Options for packaging your Python code: Wheels, Conda, Docker, and more - <AUTHOR> https://pythonspeed.com/articles/distributing-software/ <comment><USER2> There is also zip app [1] if you already have python installed

[1] [https://docs.python.org/3/library/zipapp.html](https://docs.python.org/3/library/zipapp.html)

</comment><comment><USER3> This seems to be focused on packaging _applications_ , and suggests that wheel is not good enough if you have a dependency on a C library. I am surprised since I thought you could embed a C library in a wheel.

I would like to know, is wheel+pypi an acceptable way to go to package and distributed a Python _library_ that includes a C library (so/dll)?

I get the impression that big libraries like numpy and tensorflow use this method to pretty good effect. It seems easier than trying to compile the C libraries on the target machine, but is it quite difficult to achieve multiplatform support this way?

<comment><USER4> It depends on what you intent to do by including a C library. It's a good choice you want to use that library in your Python modules. If you expect users to link to that library directly, wheels would be a poor choice that leads to never ending headaches (not wheel's fault, but mainly due to how shared libraries are designed).

</comment></comment><comment><USER5> > The Conda package system packages both Python packages and C shared > libraries and the Python interpreter into Conda packages.

This doesn't sound correct. Conda packages don't actually include the entire Python interpreter in them right?

A prerequisite to installing Conda packages is to have Anaconda/Miniconda installed which brings in the Python interpreter and a given set of packages depending on the version you install but that doesn't mean that each Conda package will be carrying the interpreter with it.

<comment><USER6> That's not what I meant, but rather "Python is a Conda package too, a dependency." I'll rephrase to make it clearer.</comment></comment>


How Three Nobodies Built NBA's Most Powerful News Site - <AUTHOR> http://online.wsj.com/public/article/SB120605508959553157-db6pLJ6mI8qnMd7RiRcoyeTeEDQ_20090321.html?mod=rss_free

<comment><AUTHOR> "His time zone gave him a five-hour head start on his closest U.S. rivals."

I wonder how well this advantage can work in other industries.

<comment><USER2> I know someone in NYC who had to work a once-monthly week of night shift hours to handle the London financial markets opening. The shift was allocated in round-robin fashion amongst the trading desk members. In other words, the time advantage in certain industries may be neutralized because resources are allocated to address it.

<comment><USER3> That sounds really shitty. Work 1 out of 4 weeks (roughly) at night. Talk about a rough week. I feel like i'd be continually out of sync. Just when I was back to normal I'd have to work all night again..man. Or all day.

<comment><USER4> I agree, but many people do a variance of this on the weekend. Where during the week they sleep from 10 or 11 pm until 6 or 7 am. Then, on the weekend they sleep from 2 or 3 am until 10 or 11 am.

</comment></comment></comment></comment><comment><USER5> A content site. Some of the best ideas are old ideas.

</comment><comment><USER6> Cool article.</comment>


Ads are dead, long live ads - <AUTHOR> https://medium.com/@markosavic/ads-are-dead-long-live-ads-c298985a6545 <comment><USER2> Consumer is king.</comment>


Coronavirus by Derek Lowe - <AUTHOR> https://blogs.sciencemag.org/pipeline/archives/2020/01/27/coronavirus <comment><USER2> This is one of the few well-written and useful articles I've seen. Most of what I'm reading, even from scientists, is hyperbole or uninformed speculation and extrapolation based on extremely limited information.</comment>


Clean up the oil spill with hay - <AUTHOR> http://www.youtube.com/watch?v=k5SxX2EntEo

<comment><USER2> I recall reading a few years ago that human hair could be used the same way. It seems there are a lot of natural materials that work well for absorbing oil; I'm not sure if this is what's used in the "oil absorbing booms" the Coast Guard's been deploying, but these are made from wood: <http://www.clear- passage.com/absorb.html#anchor799344>.

As a side note, I think it's cool that this was presented by a guy with a Southern (US) accent and overalls. Hopefully this will do some small part to breaking the stereotype that people with a Southern accent are not intelligent.

<comment><USER3> <http://www.matteroftrust.org/programs/hairmatsinfo.html>

this group collects hair donations to be used for exactly that purpose.

<comment><USER4> My most recent haircut is participating in this exact program. It'll be floating around the Gulf soon :)

</comment></comment></comment><comment><USER5> Good write up on why the hay might not work: [http://senseofevents.blogspot.com/2010/05/hay-for-oil- spill-...](http://senseofevents.blogspot.com/2010/05/hay-for-oil-spill-is-no- plan.html)

<comment><USER6> Also think about what you'd do with the hay once you manage to somehow collect it. You'd have all this hazardous waste that you'd have to end up burying or burning.

Sounds like the existing boats + tools they have work fine for cleaning it up, it's just a matter of scale. The real problem is that the leak is huge, and there's just craploads of oil to clean up.

<comment><USER7> Granted, this is on a massive scale that I have a hard time even imagining...but Paul Stamets has shown phenomenal results using oyster mushrooms to do mycoremediation.

</comment></comment></comment><comment><USER8> This seems like a much better solution than dispersing chemical agents into the water. KISS.

</comment><comment><USER9> Simple solutions are quite often the best. I do not see a problem with this as it does make perfect sense. Oil floats but is not a solid and hay is a very textured solid that would affix itself to oil pretty strongly (think getting oil on your hands vs on a pane of glass).

<comment><USER10> From what I read somewhere (I think it was posted here, but I can't find it at the moment), a large amount of the oil is suspended in the water beneath the surface.

<comment><USER9> Huh? I can't find that anywhere. I can only find that it's traveling beneath the booms put in place to contain the oil (probably due to waves/volume).

Oil is low density and by nature floats. Oil is non-polar while water is polar (so they naturally separate). This isn't some magical oil spill - it has the same rules as pouring vegetable oil into a glass of water and stirring it.

I'm interested in what could cause oil to be suspended beneath something more dense (water). Perhaps it is just taking longer to reach the surface due to currents?

<comment><USER11> Well, it's not like it's going to go straight up. Keep in mind that if you pour vegetable oil into water and stir it vigorously enough, some of it _will_ go beneath the water (admittedly, it won't dissolve into it or anything, it'll remain in big globules). A lot of oil is below the surface due to the sheer volume coming out (and yes, currents carrying it around :)).

</comment></comment></comment></comment><comment><USER12> In one of the videos the guy mentioned that back in the 90's there was a reason that A LOT of hay needed to be sent to Montana or some other state in the northern midwest. He used that as an argument for why they could get enough hay. Does anyone know anything about that? I have been unsuccessful in my search on google.

<comment><USER13> I think it could be related to drought conditions (or, perhaps flooding) where the hay harvest failed. Google "hay drought midwest south" etc and you will see that hay has gone both ways a few times over the past decades. A list for farmers/others to share info about supply / demand is at <http://www.haylist.umn.edu/>

</comment></comment><comment><USER14> Wait a second, how are we to clean up the hay?

<comment><USER15> With spiders of course. The cows will be somewhat harder to remove.

<comment><USER16> We just need experiment happy Aliens to clean up the cows . . .

</comment></comment></comment><comment><USER17> They _are_ currently using hay bales on the gulf's beaches as a barrier and absorbant.

</comment><comment><USER18> I think we should take the annual salary of the managers who engineered, inspected and owned and operated the rig, convert it into dollar bills and use that to soak it up.

I'd like to see this work but seriously this demo is far too simple, show me a demo with a few hundred square feet with very light oil densities and much less hay available.</comment>


Deploy mobile apps from Dropbox - <AUTHOR> http://harp.io/

<comment><USER2> This looks very similar to my startup's product, Site44: www.site44.com.

I'm not sure I follow the connection to "mobile," though. Some of the examples (like a static blog or landing page) don't sound at all specific to mobile. Can someone explain? Is this general-purpose static hosting, like Site44, or is it something different?

<comment><USER3> > This looks very similar to [...] www.site44.com.

That was my first thought (site44 is pretty awesome btw). Will Harp do anything more than serve content from a Dropbox folder?

<comment><USER4> I got an email asking the same question. Without going into specifics here is what I can say at this time.

I have not used site44 so I cant speak in depth about the differences.

I can say Harp will be focused on solving domain specific problems, rather than focusing on the technical solution. This means that we look at the problems developers are having and adapt the Platform to address those needs. I believe strongly that people really just want pain removed from their development process. You can expect Harp to have things like rollbacks, diffs, preview urls, staging and production releases etc. Harp does not just turn a Dropbox directory into a website. We see Dropbox as a great way to get files into the cloud in a way that offers a low barrier of entry for beginners. Dropbox is not tied in any way to our architecture and Harp may support other competing services (or even git) if that appears to be the desire of our users.

Hope this answers your question.

<comment><USER2> This certainly helps my understanding; thanks for responding.

</comment></comment></comment></comment><comment><USER5> A mobile accessible interface is a big deal for many. A simple SSH / SFTP / etc connection for file management will suffice, rather than having some proprietary client model restricted to a couple of operating systems.

Just my $0.02

</comment><comment><USER4> Hey everyone, I'm one of the creators of the Harp Platform. If you have any questions, I'd be happy to address them.

<comment><USER6> The site is sort of sparse on details. Just gave you my email addr. Can I link this up with my own DNS?

<comment><USER4> yep. we have CNAME support.

</comment></comment></comment><comment><USER7> I was about to have a conniption, but then I saw this:

> _Learn to Program_

> _We created the absolute best Platform for learning web development. Harp > removes all the complexity, and gives you the environment you are already > comfortable with._

This is a really awesome idea for getting beginners into mobile app development. PHP did a lot to reduce the barrier to entry for traditional web application development and I think this could have the potential to do the same for mobile.

Looking forward to seeing how this pans out.

</comment><comment><USER8> Just to be clear, this only supports HTML, CSS and Javascript? So learning to program web applications doesn't include anything with a database or that requires secure access (i.e., authentication/authorization) unless (possibly) something like Parse is used as a backend and no Ruby, Python, PHP or other server-side languages.

</comment><comment><USER6> I've wanted to tackle this idea forever, it's always seemed like low-hanging fruit. I'm super excited to see someone take it on full-time. Best of luck!

<comment><USER4> Thanks! Agreed. Dropbox is a significant step forward when it comes to getting assets into the cloud. I think it will make life much easier to be able to iterate on sites within a directory on your file system with no extra bagage.

</comment></comment><comment><USER9> This is an interesting concept. I'm developing a blogging platform leveraging dropbox—that it's actually powering my website—but I've taken i different approach and I'm parsing on the server the markdown files. I haven't actually thought about using it with static html files, this approach have the benefit of greater flexibility in the type of content you can provide.

</comment><comment><USER10> This looks awesome. Any way I can get early access? Im working on a project I would love to try this on

<comment><USER4> Rather than doing a long term private beta. We are gearing up to go directly to a public beta very soon. Those that sign up on the list will be first to be notified when we go public.

</comment></comment><comment><USER11> The Public folder in my Dropbox is already my Poor Man's CVS, this is a great idea. Best of luck!

</comment><comment><USER12> This looks like an interesting project ;) I'll definitely check it out.

</comment><comment><USER5> The site crashes Dolphin on Android 2.2.x

</comment><comment><USER13> Awesome, can't wait to try this out!</comment>


Ask HN: How do you round your client's billing? Round, ceil, floor? - <AUTHOR> I am building time tracking and billing system. And I don't know how to round the time worked.<p>For example: a task done in 1 hr and 20 minutes - does it become 2 hrs, or 1 hr, or maybe 1.5 hrs? <comment><USER2> It becomes 1.3 hours. Usually the exact dollar amount doesn't matter to clients, so I just try to be precise. What downside is there in being precise?

</comment><comment><USER3> whatever you do, don't round to 1 hr all the time, unless you price that in...</comment>


Eleven babies die after Dutch women given Viagra in drug trial - <AUTHOR> https://www.theguardian.com/world/2018/jul/24/eleven-babies-die-dutch-women-viagra-drug-trial <comment> DC-3 > The women taking part in the trial all had unborn babies whose growth had > been severely limited in the womb. The children's prognosis, given a lack of > available therapy, was regarded as poor as a result.

Key point to be made. These aren't healthy babies dying.

<comment><USER2> It's a little more nuanced than that though.

The babies were delivered. This wasn't a fetus dying in the womb.

From the article:

"The hospital said: "An interim analysis by Amsterdam UMC, location AMC, showed that sildenafil may be detrimental to the baby after birth. The chance of a disease of the blood vessels of the lungs appears to be greater and the chance of death after birth seems to have increased.

"The researchers found no positive effect for the children on other outcomes. All adverse effects occurred after birth … "

Further, the incidence was much higher in the test group compared to the control group.

It was a last ditch attempt, where the prognosis for the fetus was perhaps already poor. But it is still heart breaking. There is so much we don't know about fetal development that there may be no alternatives to doing such tests. But still..:/

I feel for the parents and the scientists involved. It is a terrible burden. But perhaps that's just the nature of working with such high risk populations. I hope they find the strength to continue testing other alternatives.

</comment></comment><comment><USER3> > The trial was terminated last week when an independent committee overseeing > the research discovered that more babies than expected were being born with > lung problems.

I heard one of the researchers on the radio. What I understood from it is they decided to abort the trial before the mortality rate became statistically relevant. However they had indicators there was a chance it would.

I feel like the article is a bit sensational. Could anyone with more knowledge then me shed some light on this?</comment>


Apple, AT&T sued for lack of MMS capability - <AUTHOR> http://www.tgdaily.com/content/view/43616/118/ <comment><USER2> It's rare I see a class action suit with merit, and this is one of them. If it was just Apple advertising it, it wouldn't be as big a problem (since it does work with other carriers elsewhere), but a carrier clearly advertising something they don't support is just ludicrous.

<comment><USER3> > It's rare I see a class action suit with merit, and this is one of them. If > it was just Apple advertising it, it wouldn't be as big a problem

So only partial: the suit against AT&T makes sense (especially if they're advertising it…), again Apple not so much.

</comment></comment><comment><USER4> Apple needs to move away from exclusivity. Networks would be falling over themselves to cater for iPhone users if there was a choice in the matter.

<comment><USER5> Just guessing, but I'm sure they can't wait to get away from AT&T themselves.

When they first introduced the iPhone, they didn't have the leverage the do now.

</comment></comment><comment><USER6> "The class action suit alleges the Louisana suit will consist of at least 10,000 individuals" Enjoy your $.10 settlement and watch AT&T continue as they were.

<comment><USER7> Beats bending over for it. How do I get my $.10 ?

</comment></comment><comment><USER8> I think that maybe this could have some traction and get AT&T more in line. Though I don't know since the suit seems to be based on some fallacies. AT&T does support MMS for phones that are not the iPhone. Credible speculation seems to be that AT&T flexed their muscles with Apple (and anyone who saw the WWDC 2009 keynote can attest annoyingly so to Apple) to delay MMS on the iPhone until they upgraded their towers more to handle the load. My friends and I would send each other MMS messages from our Sony Ericsson & Nokia phones years ago. I was on T-Mobile and they were on AT&T.</comment>


How to outsource small data entry type jobs offshore? - <AUTHOR>

I have a few internet research and data entry type tasks that  I'd like to farm out. I'd think this would be perfect for outsourcing overseas somewhere. Is there a website for brokering jobs ?
Thanks,
Joe <comment><USER2> I have used odesk successfully for some small data entry jobs.

</comment><comment><USER3> oDesk, elance, fiver.com</comment>


Maybe Not [video] - <AUTHOR> https://www.youtube.com/watch?v=YR5WdGrpoug <comment><USER2> I really like this idea of composing selectable attributes as schemas (ala RDF). I've been fairly reluctant in adopting specs into my own code, mostly because in a lot of cases I just didn't see the benefit (not for the things I typically do, not saying I wasn't interested in generative testing and the likes ... those still seem very promising but also hard to get right). Especially, when dealing with "distributed" things (like the world wide web, where everything is maybe and only some things useful). And, RDF got this surprisingly right. I was sort-of half expecting him to also introduce PROLOG into it, but maybe next time. The idea of collections of subject-predicate- object statements forming an isomorphism with graphs, and sets of these statements form concrete "aggregates" plays extremely well with the idea of unification through search.

Somewhat tangentially, it also keeps reminding me somehow of Alfred North Whitehead's concepts of reality as process flows [https://en.wikipedia.org/wiki/Alfred_North_Whitehead#Whitehe...](https://en.wikipedia.org/wiki/Alfred_North_Whitehead#Whitehead's_conception_of_reality)

"In summary, Whitehead rejects the idea of separate and unchanging bits of matter as the most basic building blocks of reality, in favor of the idea of reality as interrelated events in process. He conceives of reality as composed of processes of dynamic "becoming" rather than static "being", emphasizing that all physical things change and evolve, and that changeless "essences" such as matter are mere abstractions from the interrelated events that are the final real things that make up the world."

<comment> ISO-morphism Here's Rich Hickey giving a talk in 2009 guided by Whitehead quotes [1]

[1] [https://www.infoq.com/presentations/Are-We-There-Yet-Rich- Hi...](https://www.infoq.com/presentations/Are-We-There-Yet-Rich-Hickey)

</comment></comment><comment><USER3> Hickey's `Maybe` example feels misguided (about breaking existing callers). If Maybe is an input just keep the original function around and provide a new one that wraps it.

        originalF :: x -> y

        f :: Maybe x -> y
        f None = newDefaultBehavior
        f (Some x) = originalF x

If `Maybe` is an output then existing callers SHOULD be broken, because they must now handle a new possibility of failure they didn't before. The fact that this doesn't happen in Clojure is actually a source of pain for me.

It's also rather interesting that Hickey also comes to the same conclusion that optionality doesn't belong in a data structure, but for slightly different reasons: [https://news.ycombinator.com/item?id=17906171](https://news.ycombinator.com/item?id=17906171)

<comment><USER4> If x represented a set with some values

      x = {RED, GREEN, BLUE}

It would be really swell if the optional type `Maybe x` were a strict superset:

      Maybe x = {RED, GREEN, BLUE, None}

This means functions that map `Maybe x -> y` can accept values of type `x` without issue.

But in Haskell (and OCaml) it's not. What we actually have is something more like

      Maybe x = {Some(RED), Some(GREEN), Some(BLUE), None}

which is a totally different set from `x`, which is why functions which shouldn't break, ultimately do.

<comment><USER5> The downside of that (which can be provided by union types) is that `Maybe (Maybe X) == Maybe X` which may or may not be what you're after. The particular weakness is the interplay with generics where `forall t. Maybe t` depends upon the `Maybe` and the `t` not interacting. If you've got `forall t. t | null` then this type may secretly be the same as `t`---and if you handle nulls then it might conflate meanings unintentionally.

<comment><USER6> So you're saying that the one Nothing has a different meaning than the other Nothing, and that this is something that anybody would want? Or that we have a Nothing and a Just Nothing? I'm sorry, but I don't get how that would be considered good design in any context. Do you have any example where this would be considered sensible?

<comment><USER5> I am.

In any concrete context, Maybe (Maybe A) could _probably_ be simplified to just Maybe A as we expect. Alternatively, we could be in a situation where there are two notions of failure (represented here as Nothing and Just Nothing) in which case we'd be better off simplifying to Either Error A where Error covers you multiplicity of error cases.

But while these are all obvious in a concrete context, what we often are doing is instead compositional. If I want to write code which works over (Maybe a) for some unknown, library-user-declared type `a` then I may very well end up with a Maybe (Maybe Int) that I can't (and mustn't) collapse.

As a concrete example, consider the type of, say, a JSON parser

        ParserOf a = Json -> Maybe a

We hold the notion of failure internal to this type so that we can write

        fallback : ParserOf a -> ParserOf a -> ParserOf a

which tries the first parser and falls back to the second if the first results in error. We might also want to capture these errors "in user land" with a combinator like

        catch : Parser a -> Parser (Maybe a)

If we unwrap the return type of `catch` we get a Maybe (Maybe a) out of a compositional context (we can't collapse it). Additionally, the two forms of failure are distinct: one is a "handled" failure and the other is an unhandled failure.

<comment><USER7> > In any concrete context, Maybe (Maybe A) could _probably_ be simplified to > just Maybe A as we expect.

And doing so is just what `join :: m ( m a ) -> m a` specialises to for `m = Maybe`!

<comment><USER5> That's just one way to do it. Another might be

        collect :: Maybe (Maybe a) -> Either[Bool, a]

<comment><USER7> But you mentioned simplifying `Maybe (Maybe a)` to `Maybe a`, which your `collect` doesn't do (at least not directly).

(Also, shouldn't `Either[Bool, a]` (which I don't know how to make sense of) be `Either Bool a`? Even with this signature, I'm not sure what the implementation would be, and Hoogle doesn't turn up any obviously correct results ( [https://www.haskell.org/hoogle/?hoogle=collect](https://www.haskell.org/hoogle/?hoogle=collect) [https://www.haskell.org/hoogle/?hoogle=Maybe+%28Maybe+a%29+-...](https://www.haskell.org/hoogle/?hoogle=Maybe+%28Maybe+a%29+-%3E+Either+Bool+a) ), but that's probably my fault.)

<comment><USER8> I think the obvious implementation is `maybe (Left False) (maybe (Left True) Right)`

If we have a value then we clearly have both layers. If we don't have a value then we need to distinguish Nothing from Just Nothing by way of the book.

<comment><USER7> Oh, I see; we're thinking of `Maybe a` as `a + ()`, and then identifying `(a + ()) + ()` with `a + (() + ())` and then `() + ()` with `Bool`. Thanks!

<comment><USER8> Right, exactly!

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment> Avi-D-coder Could the title be changed to include "\- Rich Hickey". I know I am certainly more likely to click the link when it's one of his talks.

<comment><AUTHOR> It did originaly. It is the full title and, without it, it's very vague. Maybe if I had remembered to put [video] in there, the mods wouldn't have touched it. Or maybe not.

<comment><USER9> It's pretty meaningless currently ("Maybe Not [video]"). It would be nice to know, at the very least, that it's a video of a _talk_ , but info. about the actual content of the talk would be preferable.

</comment></comment></comment><comment><USER10> Great talk, really excited to see how he is going to solve imports and reification for Clojure [so far only rust and haskell have this figured out].

I'm just so glad that Clojure exists, it is doing all the good design things to make programming pleasant but it has a different approach from the usual suspects which is incredibly valuable!

Being dynamic and interactive is great for UI/UX design since that, especially, benefits from the tight feedback loop and I'm becoming more and more bullish on making the type system separate like this and thinking of it as synonymous with tests, it makes a lot of sense (separation of concerns...)

Also coming from mathematics I can see a analogy to the preference of working in open sets (so that you can always take a point arbitrarily close to the edge and still make an open neighborhood around it) and what he is calling an open system. This preference for open sets over dense ones seems counterintuitive at first sight but is the basis on which analysis is built. Type systems feel a bit 'dense' in the sense that they force you to write programs that are overspecified?

Anyway I just look forward to seeing experience accumulate with these different technologies so that we may learn more about how we ought to design systems !

</comment><comment><USER11> "I got six maybe sheep in my truck."

</comment><comment><USER12> I have this strange feeling, that first half-hour was totally unnecesary for what the sencond half is. I mean, that it feels that he have to rant always about. Like ok, this ideas are wrong, this is my idea that is totally new(not really) and is the right thing to do. Nowadays, that ranting about Java is not so cool, he have to rant about types. Only to finish saying that he is going to add to Spec something that have already been implemented in Clojure [https://github.com/plumatic/schema](https://github.com/plumatic/schema). So at the end of the talk, what's the point?

</comment><comment><USER11> Punchline of the talk starts at 38:00

</comment><comment><USER13> I'm really excited about the way this is progressing. As a way to think of it (and not demote it in any way) is that it's like PropTypes with React done with reusability and less verbosity. The reference to GraphQL really makes it clear that we want deep separated specification.

</comment><comment><USER14> Great talk! I've watched a lot of Hickey's talks over the years, and thought he might have "run out of steam" by now. But there are some new insights here that I enjoyed.

One of his main points is that Maybe is context-dependent, and other aspects of schemas are as well. This is a great and underappreciated point.

It's related to a subtle but important point that Google learned the hard way over many years with respect to protocol buffers. There's an internal wiki page that says it better, but this argument has spilled out on to the Internet:

[https://stackoverflow.com/questions/31801257/why-required- an...](https://stackoverflow.com/questions/31801257/why-required-and-optional- is-removed-in-protocol-buffers-3)

In proto3, they removed the ability to specify whether a field is optional. People say that the reason is "backward compatibility", which is true, but I think Hickey's analysis actually gets to the core of the issue.

The issue is that the shape/schema of data is an idea that can be reused across multiple contexts, while optional/required is context-specific. They are two separate things conflated by type systems when you use constructs like Maybe.

When you are threading protocol buffers through long chains of servers written and deployed at different times (and there are many of these core distributed types at Google), then you'll start to appreciate why this is an important issue.

(copy of lobste.rs comment)</comment>


Hands-on with Baxter, the factory robot of the future - <AUTHOR> http://arstechnica.com/gadgets/2014/06/hands-on-with-baxter-the-factory-robot-of-the-future/ <comment><USER2> I recently did some research on robot state-of-the-art, and Baxter is one of the standouts. Baxter combines advanced sensors with an interesting approach to learning a mechanical routine, ostensibly trained by a factory line worker, not a programmer. The founder was also one of the iRobot founders: [http://newsoffice.mit.edu/2013/rodney-brooks-rethink- robotic...](http://newsoffice.mit.edu/2013/rodney-brooks-rethink- robotics-0809)

This isn't totally uncharted waters. There are similar robots/arms out there, cheaper even than Baxter's ~$20K price tag: [http://www.universal- robots.com/](http://www.universal-robots.com/)

I think the semi-human factory robot is going to be a big robot segment eventually, and part of the path to robots moving around within society. Companies like Rethink Robotics end up working on necessary problems like how not to whack humans with giant robot arms, and make humans feel comfortable with the robots next to them.

</comment><comment><USER3> My firm does industrial automation consulting. I've seen one of these in the wild at an in-house demo for a furniture manufacturer and we have an auto parts supplier who is looking at using them in production.

They seem to have a ludicrously low weight limit (I remember reading 5 lbs) and don't seem capable of tasks where you need a programmer for automation (welding, quality checking, etc, etc.)

I would not discount the likelihood of managers and owners getting unduly excited and buying ten of them before having to quietly admit to themselves it was a mistake.

</comment><comment><USER4> I think they may a decent set of sales, but that's more about cutting out the programmer from the process (it's a fairly basic packing robot by the looks of things and if your factory is laid out well enough to fit it in, you will probably have a more specialised robot doing that work anyway. This seems too generic too be effective.

I think the biggest open market here is turning things that are not factories into factory-forms. For example my house is a new build and it was stuffed up (forgot to put in insulation). Now as the CEO of the building company I would rather have put QR codes on all my planks of wood etc, have them photo graphed in place then put the plaster on top, thus being able to record the processes, add analytical to something that is "in the field".

The major benefits will not come from replacing humans with robots but with replacing lack of control with control.

</comment><comment><USER5> I got a chance to see and play with one of these not too long ago. Cool technology, not really ready for prime time.

</comment><comment><USER6> Anybody else getting flashbacks to Fallout New Vegas?

</comment><comment><USER7> This isn't a "factory" robot. Maybe a toy for some hardware startup to waste VC funds on but not something you'd want in a proper factory.</comment>


Ask HN: SMS to verify users - <AUTHOR>

Is sending a user a code via SMS a good way to prove they are a real user?  Couldn't a bot be attached to a phone which fills out forms and waits for codes for that site? <comment><USER2> I forgot my password on Google and asked for the code that would allow me to change it to come via SMS. Took 2 weeks :(

I'm from Brazil, maybe that's why it took so long.

</comment><comment><AUTHOR> Thanks for the comments. I appreciate everyones incites.

</comment><comment><USER3> just add a unique-constraint to your phone-number-column and it should be fine.

<comment><USER2> You're right about some kind of constraint, but what would happen if the user says the SMS never came and needs another? :) Some kind of rate limiting (one per day?) is necessary.

</comment></comment><comment><USER4> It seems a lot more resource intensive to have a bot responding to SMS messages from many different phone numbers than more traditional ways of gaming the system.

So unless becoming a user on your site is worth much much more than the average site, just the increased barrier, even if not totally secure, should be enough to keep the vast majority of bots away.</comment>


"Real developers don't use UIs": The value of web UIs for CLI-oriented users - <AUTHOR> https://medium.com/design-ibm/real-developers-dont-use-uis-daea7404fb4e <comment><USER2> That was a well written and entertaining article. A bit long for my taste and I feel like it could have been said in fewer words, but like I mentioned, it was entertaining.

What this makes me wonder is how much effort should go into each User Interface. You describe a web GUI (in this domain) to be a good place for people to learn about something new and maybe kick the tires. It can also speed up their interactions via visual tricks. However, you mention that productive, at scale, and "more money" use occurs more in the CLI. Does that mean companies should make their UI better at educating the CLI and worry less about doing things in it and make the CLI be the encouraged primary form of "Doing"?

On top of that, making a GUI requires front end/backend development, UX, visual, research, and a whole lot of time while a CLI requires UX (maybe) and backend development and is overall simpler. I feel like the positives and negatives described in this article don't really support making a UI do anything more than discovery and education on the CLI. And CLI are finally attempting UX improvements like your example from Yeoman. They are taking the best bits from the Usability of GUI (color, shapes, iconography, recommendations, etc)and putting them in the CLI. Does that diminish the relevance beyond education and marketing of a GUI in this domain even further?

<comment><USER3> >making a GUI requires front end/backend development, UX, visual, research,

Doing a CLI also requires, at least, back-end development and research. Doing a decent one requires a tremendous focus on UX.

<comment><USER2> Definitely back-end and it is exciting to see all that UX is bringing to CLIs, but relative to a full front end GUI it is much more straight forward. (Not to discount the hard work CLI developers do since it is still plenty complex)

</comment></comment></comment><comment><USER4> Kind of a turn-off that it jumps immediately from CLI to web UI, without even considering native UI. Macintosh developers worked quite effectively for almost two decades without any sort of standard, out-of-the-box command line environment; sure some used Macintosh Programmer's Workshop, but the vast majority lived in IDEs like THINK Lightspeed Pascal and C (later Symantec THINK Pascal and C) and Metrowerks CodeWarrior, and were extremely satisfied with their experience.

</comment><comment><USER5> The article is a beast but there is a lot of good information in there. I find that I try to do as much as possible from the keys when I'm doing programming related tasks. An IDE like vscode is a good mix of UI and CLI for me.

That being said, I've been excited in the past seeing a new take on IDE's with things like LightTable (I'm not positive that's the name...) which have pushed the needle even further on the UI/CLI balance.

</comment><comment><USER6> There's a ton of great info packed into this article. It's definitely been a struggle over the years to find a balance between when to prioritize CLI over UI development for Cloud services, but I think they arrived at a sweet spot when it comes to building complementary experiences that help one out where it is most appropriate.

Disclaimer: I work for IBM Cloud

<comment><USER7> I used to work on a product UI that provided the equivalent CLI command for every action you perform in the UI. Use the UI to learn the CLI - complementary experience.

</comment></comment><comment><USER8> I always feel like CLI is for power user's for people that already know what they are trying to accomplish and want to batch together scripts to do it. A UI is better for beginner user's to become familiar with a products functioning.

From a design perspective I feel like the CLI is far too often forgotten.

</comment><comment><USER9> If we're talking about the crappy web browser ssh interface to GCE instances then yeah, it really sucks.</comment>


Programming Contest: Win a Motorola Droid and $1k in Cloud Credit - <AUTHOR> http://www.engineyard.com/blog/2009/win-a-motorola-droid-programming-contest-worst-app-server-technology-ever/

<comment><USER2> Obviously they are admitting this is the "worst app server tech", but seriously, since all of the communications are public and unencrypted, a rogue-agent could torpedo all entries by POSTing corrupt/meaningless data to the "output" endpoints during the calculation processing just by watching for properly formatted WASTE messages. A "correct" entry could then never be found.

Also, it could be the case that no combination of WASTEpoint steps could solve the problem (though they may tailor the calculation problem based on the registered WASTEpoints). I also wonder if some of the accounts may be suspended as spam mid-way through the contest?

This is an interesting idea, but I think the transport mechanism is too open.

<comment><USER3> Yup. If all the points followed each other and then just DM'd, then it would be one step better.

</comment></comment><comment><USER4> Hahha WTF? That is a very interesting... and head-scratching contest indeed.

<comment><USER5> Yeah, why on earth are they interested in this?

<comment><USER6> "they" as in Engine Yard? Promote Ruby development? Get publicity from #wa-ste if it trends, and get publicity anyways for running such an odd contest?

I think the concept of using Twitter messages to create an app is hilarious and fascinating at the same time. Even if I don't participate, I'd love to see how the contest turns out.

The thing that interests me the most is the 5-limit on WASTEpoint submissions, and the requirement to use at least 10 WASTEpoints from at least 4 different submitters, which will force contestants to rely on other people's submissions and not just their own. I wonder if this will cause potential contestants to delay building their own WASTEpoints, to wait and see what other WASTEpoints are available for use before supplementing with their own in order to complete the contest. -- On second thought, I guess that's why second and third prizes are for the WASTEpoints submissions.

Hmm, now that I think about it, to win first prize, you don't even need to code anything; just create a program listing of WASTEpoints that other people build.

<comment><USER7> > _now that I think about it, to win first prize, you don't even need to code > anything_

True, but you also need to be the first to figure out the combination of pre- existing WASTEpoints. A 'funny' progression:

1\. Contestant #1 figures out how to do the computation using 9 existing WASTEpoints and one personally created one.

2\. Contestant #1 registers said WASTEpoint to use it to submit their program listing.

3\. Contestant #2 figures out how to use Contestant #1's WASTEpoint + the 9 others, and submits the winning program listing before Contestant #1 does. Thereby winning the contest on the back of someone else that had already figured out how to win the contest.</comment></comment></comment></comment>


Ask HN: Handle or Show Errors in an Application - <AUTHOR> Someone in my team is a huge fan of "catching" errors and pretending it's works okay.
People should check the logs and see if there is something wrong. Data that is send through the stack is sometimes "invalid" because of all the handling.
I'm a fan of showing the error. Something goes wrong, it has to be fixed. And since something goes wrong, it may be shown in the frontend.
We both use logging of course :)
What is your preference? <comment><USER2> Both

Detailed errors to log files or what have you

Friendly errors to the user.

If it's an internal project, I like to get specific. "Please contact the developers at ext: xxxx and tell them this: ..."

If it's an internet facing / external user app / project - be friendly, without letting them know specifically what happened. "We had a problem retrieving your contact list. The admins have been notified. Please try again in x time" vs "couldn't connect to server... this function failed..."

<comment><AUTHOR> Handling = continue like nothing happened. So no errors/friendly messages to the end user.

<comment><USER2> But you said yourself "I'm a fan of showing the error."

Showing an error and allowing the user to decide what to do is apart of the handling process, no ?

You can try / catch all day long, but if the app crashes or doesn't produce the right data - the user must be informed, no ?

<comment><AUTHOR> Yes, showing a friendly error. Is also showing the error.

The difference was silent fail ( not informed) or not.

Like I said before, where I explained the definition of handling in this context:

> Handling = continue like nothing happened.

You agree with me in a question, so it seems.</comment></comment></comment></comment>


How to Negotiate with a Liar - <AUTHOR> https://hbr.org/2016/07/how-to-negotiate-with-a-liar <comment><AUTHOR> On point, indeed.</comment>


Google Earth Beaten By Autorendering From Photos - <AUTHOR> http://news.slashdot.org/article.pl?sid=08/06/07/2024254&from=rss

<comment><USER2> Re: aerial photos. A civil engineering/surveyor friend of mine told me that he nicknamed the small aerial plane he tagged along on once to do these aerial surveys the vomit comet - because of the quick back-and-forth required to not miss coverage.

</comment><comment><USER3> I've lived in Stockholm and I've got to say this is an amazingly good representation. It's really, really slow.

The buildings seem to rise from the ground like zombies as they're progressively rendered in more detail. Once again, way cool.</comment>


Firefox 16 unprefix CSS Gradients, Animations, Transitions & Transforms - <AUTHOR> http://hacks.mozilla.org/2012/07/aurora-16-is-out

<comment><USER2> > IndexedDB has reached Candidate Recommendation status and has been > unprefixed too. This is amazing.

Folks, this is far more important than CSS. Firefox has the most complete implementation of IndexedDB. More than anything else, it is what will enable us to write completely client-side applications.

<comment><USER3>
      > More than anything else, it is what will enable us to
      > write completely client-side applications.

It seems to me that developers have been writing completely client-side applications for forty years.

</comment></comment><comment><USER4> The new developer command-line interface (Shift+F2) looks really neat, though I'll have to play with it to see if it really turns out to be useful. Here's a list of commands:

      addon - Manipulate add-ons
      break - Manage breakpoints
      calllog - Commands to manipulate function call logging
      console - Commands to control the console
      cookie - Display and alter cookies
      dbg - Manage debugger
      edit - Tweak a page resource
      export - Export resources
      firebug - Web Development Evolved
      help - Get help on the available commands
      inspect - Inspect a node
      pagemod - Make page changes
      pref - Commands to control settings
      resize - Control Responsive Design Mode
      restart - Restart Firefox
      screenshot - Save an image of the page
      tilt - Visualize the webpage in 3D

<comment><USER5> Thanks! They should disable the flyout completion for now, though. It causes the input box to lose focus, can't type a command with that.

</comment></comment><comment><USER6> For all the lovers of the "prefixes are not useful, just do without them":

> Also the <angle> changed: before, 0deg pointed to the right; now it points, > consistently with other angles in the CSS spec, to the top.

<comment><USER7> Which is consistent with how all the other browser does it.

And I don't doubt that the prefix debacle is the reason they are getting rid of them now.

<comment><AUTHOR> No, Opera and Microsoft are implementing the new syntax too (IE 10 unprefixed and Presto 2.12, which is under development, too).

Hopefully WebKit will follow soon (if somebody has the bug#, I'm interested)

</comment></comment></comment><comment><USER8> My blood boils every time I see an odd change in a perfectly fine way of doing things.

Compare this:

        linear-gradient(top,#fff,#000)

to this

        linear-gradient(to bottom,#fff,#000)

Why?

<comment><AUTHOR> The CSS WG wanted that both the <angle> and the keywords to be consistent: both are indicating a direction now. The 'to' was added in order to let the old and new syntax coexist during the transition time.

</comment></comment><comment><USER9> Proving what time of day you submit on HN is critical

<http://news.ycombinator.com/item?id=4278862>

Still, good information to know.

<comment><AUTHOR> And I did a search before to post!

<comment><USER9> No worries.

</comment></comment></comment><comment><USER10> I can't tell from the post, but is the <angle> argument for linear gradients still optional? Ie. is the following still valid?

        linear-gradient(#fff, #eee)

<comment><USER11> Yes, that works in my Firefox 16.

<comment><USER10> Great, thanks! I find I use top-to-bottom gradients about 90% of the time, so I'm glad the succinct form is still valid.

</comment></comment></comment><comment><USER12> Bad timing on the naming... Aurora?

<comment><USER13> Firefox Aurora has existed for the last few years. It's their preview release of stuff, equivalent to Chrome Canary.

<comment><USER12> Yes, but in light of the current events, you'd think it'd be changed.

<comment><USER14> Why, this is a browser, not some evil plot? They could dedicate it if they wanted to.

<comment><USER12> No, but at the same time, it's just respectful to not keep the codename of a project that is related to such a tragic event.

<comment><USER15> My heart goes out to the victims and their families of the Aurora incident.

However, "Aurora" as a name is simply too common to be replaced.

</comment></comment></comment></comment></comment></comment><comment><USER16> Ohhh, how long have I waited for this moment.

</comment><comment><USER17> ugh...

i'd like to see firefox slow down with the features and focus on stability.

firefox seems to be in the same boat as microsoft office, eclipse, gnome, and almost all GUI software. each new version adds meaningless features while bugs proliferate unchecked. (Given that this problem affects GUI apps of all kinds, perhaps it can't be solved?)

the latest thing that drives me up the wall about Firefox is that it's continually alerting me that my "plug ins are out of date" but as of the last few months the "plug in update" procedures are all broken -- I'm scared to update Java because the last time I did that I broke all my Java apps, and it seems like updates to Adobe products on windows don't work at all today.

<comment><USER18> "Each version adds meaningless features" This is because the new rapid-release system lets them publish each feature as soon as it is ready. Since big features generally take longer, it's not surprising that each little release has fewer big features.</comment></comment>


Steve Bannon as WH chief strategist (Preibus is Chief of staff) - <AUTHOR> http://www.cnn.com/2016/11/13/politics/donald-trump-reince-priebus-white-house-chief-of-staff/index.html <comment><USER2> Bannon's Alt right website Breitbart.com headline:

Bill Kristol: Republican Spoiler, Renegade Jew

[https://www.google.com/amp/www.breitbart.com/2016-presidenti...](https://www.google.com/amp/www.breitbart.com/2016-presidential- race/2016/05/15/bill-kristol-republican-spoiler-renegade- jew/amp/?client=safari)

Edit: not sure if that was before or after he took over Breitbart

<comment><USER3> I believe he is not day to day running the website any more but another person is who goes to extremes on the headlines to get more clicks. Even more extreme I mean.

</comment></comment><comment><USER4> Robert Mercer (Renaissance Technologies hedge fund) is connected to Trump in so many ways:

\- Keep the Promise super-PAC (supported Ted Cruz)

\- Defeat Crooked Hillary PAC

\- Cambridge Analytica (Trump started using their services)

\- Kellyanne Conway

\- David Bossie

\- Breitbart News Network and Steve Bannon ($10 million equity investment according to sources)

Hedge fund CEO bought himself a president? How The Space Merchants (1952, Frederik Pohl and Cyril M. Kornbluth) of him.</comment>


Is Flipboard Legal? - <AUTHOR> http://gizmodo.com/5594176/ <comment><USER2> I made some comments about this on my blog:

<http://yongfook.com/is-flipboard-legal>

I think Flipboard will get a free ride for a while. It's definitely in grey territory, but I think the excitement around it means that it represents too much opportunity to try to stamp out (if you're an old-school publisher being scraped).

It will definitely begin to get a little sticky if Flipboard's eventual business model is advertising over this content which is owned by other people _and_ has had its original ads stripped.

</comment><comment><USER3> I don't think Gizmodo is in a position to dish out legal advice.</comment>


Powerwall 2 and Integrated Solar - <AUTHOR> https://powerwall.tesla.com/?powerwall2 <comment><USER2> Quick question for the people living in the US (Target customers of the Powerwall). What is your yearly power usage?

On the website[0] they put for sizing 10kWh/day/BR. Which means 14600kWh/year for a 4 bedroom house. Here in Germany, working from home with a 4BR+office house, we are using 2550kWh/year. So, I suppose the Tesla sizing is to support a "peak day" usage, but still, I am surprised by the calculations. This is why this totally informal and unscientific survey :)

[0]: [https://www.tesla.com/powerwall](https://www.tesla.com/powerwall)

<comment><USER3> The reason their calculations are so high is because in the US, typical houses are made as cheaply as possible, pretty much with paper, plastic and vastly insufficient insulation.

That may have changed in the recent years, but holds true for most residential properties built before 1980.

<comment><USER4> What a sweeping generalization.

Furthermore, unless you're in an area of the country that requires the use of a lot of AC--or you have electric baseboard heat--insulation doesn't even play that much into electricity usage.

<comment><USER5> I can see why one would bristle at the term 'cheap', but where energy efficiency is concerned there is a big difference between the EU and US. Energy costs are higher, regulations tend to be stricter, and usage lower in the EU.

On insulation, I'm assuming you mean in areas where AC isn't heavily used insulation doesn't help electricity bills if heat is provided by gas/oil?

<comment><USER4> >On insulation, I'm assuming you mean in areas where AC isn't heavily used insulation doesn't help electricity bills if heat is provided by gas/oil?

Correct. Heavy use of electric heat is fairly uncommon as it's relatively expensive. (In the Northeast, it would be considered a serious negative if a house had only electric heat.) Of course, insulation helps with overall energy usage if there's either a lot of heating, a lot of cooling, or both--however it's provided. I'm also sure the US tends to have larger houses, more large electric appliances, and other home features that increase electricity use.

</comment></comment></comment></comment></comment><comment><USER6> For those who are looking for something similar but (being the kind of people who read HN) would like something more configurable and hackable, you might check out the products of Victron Energy[0]. They've also have an optional remote management portal[1] which allows you to set up and monitor everything remotely for years now, and most the software running locally on the devices is open source and fully modifiable (such setups are even supported!).

Full disclosure: I'm one of the developers of the mentioned Remote Management portal.

[0]: [https://www.victronenergy.com/](https://www.victronenergy.com/) [1]: [https://vrm.victronenergy.com/](https://vrm.victronenergy.com/)

</comment><comment><USER7> Solar panel roofing tiles have been around for a long time. I wonder what this will do different? Pricing? Or perhaps they are relying on brand strength alone.

Edit: I understand the urge to downvote because I'm not singing praise, but I promise I'm not trying to be overly pessimistic or critical of what Tesla is doing. Fact of the matter is, solar tiles have been done before, and failed miserably.

<comment><USER8> Marketing and business model, primarily. Previous solar tiles were more expensive than conventional solar and so are these. The difference here is that Tesla and SolarCity are marketing it as no more expensive upfront than a conventional roof replacement by keeping ownership of the roof and having buyers sign a contract committing them to buying power from it at ever- increasing prices.

There also seems to be some efficiency and aesthetic improvements over previous tiles, but those alone wouldn't be enough to make it viable.

<comment><USER9> > Marketing and business model, primarily.

And from that, hopefully, scale. Solar tiles have always seemed to be a very poor relation of solar panels. The approximately 1x1.5m panel is a sort of informal global standard, and that's meant that solar tiles have been much more fragmented, much lower scale, and much more expensive.

On the other hand in theory these solar integrated building materials should greatly reduce the associated costs of installing panels - labour is usually something like half the cost of installing rooftop solar, but if you can install a solar roof without much more effort than a normal roof, those extra labour costs are massively reduced.

If you can leverage this labour cost advantage to ramp up scale of the tiles, and get them close to the per watt cost of traditional panels, this is how you can really make rooftop solar competitive. These labour costs are why rooftop solar is so much more expensive than utility solar. If you can greatly reduce them, total costs are much more tied to the cost of the tiles themselves, the inverter, and so on, where there is enormous leeway for ongoing reductions. Very exciting.

</comment></comment></comment><comment><USER10> the cool thing is that they look good... they look like a normal roof at the angle you would see from the street in front of the house, but from above... from the angle of the sun they are transparent and you can see the solar cells.

I know some rich people that want solar but their neighborhood associations won't allow it, but I don't think they would not have an objection to these roofs. they look really nice....

I have been curious how they were going to compete with cheap chinese solar. this seems like a good strategy but one that may be easily copied.

<comment><USER11> In CA, it is illegal for HOA to block solar installations

<comment><USER12> What is HOA?

<comment><USER13> Just google it. I'm getting tired of seeing so many low effort comments. I used to come here to be informed..

<comment><USER14> Just imagine if they wrote encyclopedias in your communication style. Completely fictional example:

From Ye Great Book of All Scottish things, 856 year of the Lord, page 17: \- yepswatter : a very commonly used household object, just ask anybody around to show you one.

</comment></comment></comment></comment></comment><comment><USER15> The thing is cloud-connected, remote-controlled by Tesla. That presents a problem. Will the cloud service behind it last the life of the system? Most cloud services evaporate within five years.

<comment><USER16> "The thing is cloud-connected, remote-controlled by Tesla. "

If your use-case is backup power in case of utility failure, how does that work ? If utilities fail, the network connection to the battery may also fail, right ?

<comment><USER17> It's not hard to imagine the solution: fall back to sane defaults like every other system not connected to the cloud.

<comment><USER16> "It's not hard to imagine the solution: fall back to sane defaults like every other system not connected to the cloud."

Almost nothing behaves like this - even if it claims to.

A good example is the sonos music system. They _claim_ that it will work properly (with your local music source) without Internet access. That is false.

<comment><USER18> One example is Tesla cars. They work fine when not connected to the cloud, although you'll want to occasionally connect to install new firmware.

This whole thread is based on speculation -- the details are not yet known.

</comment></comment></comment></comment></comment><comment><USER19> [https://www.tesla.com/solar](https://www.tesla.com/solar)

For people like me who missed the solar roof.

<comment><USER20> Thanks! Can someone tell me what kind of architectural style does that house on the landing page represent?

<comment><USER21> You got 4 different answers. Something just isn't right with that:

        Modernist
        Deconstructionist Modern Style
        Muskhaus
        Contemporary

<comment><USER22> Pretty sure the Muskhaus answer was a joke, as Tesla is run by Elon __Musk __.

</comment></comment></comment></comment><comment><USER23> I have no particular desire to sign up just to watch the video, but I hope that the Powerwall 2 is compelling enough to beat out the LG Chem RESU.

For reference, the RESU is a wall-mounted Li-ion battery meant to be connected to a solar inverter. It seems to beat the Powerwall in basically every respect. It's a bit cheaper, it has a better warranty, and it has slightly lower advertised capacity but higher warranted capacity under basically all advertised conditions. But it's not cool and doesn't have a shiny video.

<comment><USER24> Tesla version integrates the inverter and has double the capacity(14kwh) for the same cost as LG Chem REsu 9kwh version

One 14 kWh Powerwall battery $5,500 Installation and supporting hardware starts at $1,000

<comment><USER25> 14/9 is not double.

<comment><USER26> The powerwall went from 7 to 14. Double.

<comment><USER25> Doh! I stand corrected.

</comment></comment></comment></comment></comment><comment><USER27> I haven't looked into it yet, but I'm curious about using utilizing my Teslas in case of emergency for power. With 75kwh+ each (leased so no concern about cycles) I don't think I'd need a powerwall at home.

<comment><USER28> Can you explain to me your economic thinking behind leasing two Teslas? Are you super rich or do you have some other thinking that went into that decision?

<comment><USER29> It's actually not a bad financial decision at all relative to other cars. Reasonably specced Model S montly lease costs after tax benefits come out to well under $1000/month. That's on par with a mid-high spec E-class or 5-series. Now factor in fuel savings and small business lease write off. Plus access to carpool lanes during peak hours and prime parkin spots.

</comment></comment></comment><comment><USER30> For $3000 this would be easy to justify just to keep my computer and network operating. I work at home and our power goes out too frequently. Is usually just for 10-20 seconds and my UPS takes care of that. But sometimes it is out for several hours - I'll say several times per year. If I can't work, I can't bill.

<comment><USER31> Where are you seeing $3000? When I set it to 1 Powerwall it tells me:

 _One 14 kWh Powerwall battery $5,500 Installation and supporting hardware starts at $1,000 Total estimate $6,500 Requires $500 deposit for each Powerwall_

<comment><USER32> Hm for that price I can install a natural-gas generator. Have power for days if necessary, full power on all circuits.

<comment><USER31> Which still ties you to the 'grid' insofar as you need the natgas supply chain, even if you have a huge reservoir you'll eventually run out. Having said that, batteries and solar panels don't have an unlimited life span either.

I'm looking at buying a petrol powered generator for reasons other than home power generation, but it will be reassuring to know we have backup power at home, but I don't think I'm allowed to store any more than 25L in one container on my suburban property. I guess that would be 25L plus each of our two cars with full tanks.

It would be fairly trivial to convert a petrol powered generator to run on propane from the barbecue gas cylinder, I've had experience installing gas kits on carburettor engines in cars.

<comment><USER32> Good points. But for me, I live on 80 acres and it happens that the county natural gas pipeline runs under it. The easement (signed in the 60's) included the right to connect to the pipeline at will. When we built the house, we exercised that right.

So even though I am rural, I don't have to buy liquid propane to heat my house. I'm tapped into a 100,000 home supply line. Its been depressurized maybe twice for maintenance in 50 years.

Not a solution for everybody. But a pretty good one for me! And everybody else on the line.

<comment><USER33> Nice setup! How much did connecting to the pipeline cost? Making an individual connection to something so large sounds expensive, but obviously I have no actual clue.

<comment><USER32> Fortunately there was a hairpin(?) connection across the road, so I agreed to connect there. That means they didn't have to depressurize just for me. Cost nothing (easement terms). However they charged me for the pipe to run the 200' from there to the house! I could have negotiated that better.

</comment></comment></comment></comment></comment></comment></comment><comment><USER34> I signed up for the original powerwall and as it turns out it's not Tesla - it's solarcity (I get it, they are the same now). Oh and by the way you have to have the solarcity solar panels installed and running for the powerwall to be installed, which has a cost of it's own.

My guess is that this isn't any different given this text:

 _Powerwall 2 is a battery for homes and small businesses that stores the sun's energy and delivers clean, reliable electricity when the sun isn't shining._

<comment><USER35> Powerwall makes a whole bunch more sense for solar storage.

If you're just using it for backup power off the grid, you have to convert AC -> DC -> AC again for use. I don't know the all up efficiency of that system, but it's far from great. Probably <70%

<comment><USER36> The specs list it as 90% efficiency round trip.

</comment></comment></comment><comment><USER37> Looks amazing! I wonder how they get wired together? How are they attached to the roof?

</comment><comment><USER38> Interesting to see Tesla of all people estimating energy consumption on the basis solely of how many bedrooms your house has, and not adding on how many electric cars you need to charge...

<comment><USER39> Bedrooms generalizes better for new customers.

...additionally, who's to say a Model S isn't a bedroom in your garage? /s

</comment></comment><comment><USER40> Many Powerwall 2's can be combined to reach potentially unlimited scale. Tesla working with SCE to build an 80 mWh Powerwall 2 stack.

Utility power required to partner with local generators. Bright future for both rooftop and Big Utility.

Solar Roofs

Solar roofs superior to normal roof? Can they look better and costs less. Maybe.

Make solar panels look like roof shingles. A textured glass tile contains/covers (?) the solar cells.

Hydrographic printing allows each tile to look unique, so the roof/house looks beautiful. No two roofs will be the same.

From street-level, it looks opaque, but is transparent to Sun.

</comment><comment><USER41> Is the patent for Powerwall v2 available somewhere as well? As per [https://www.tesla.com/blog/all-our-patent-are-belong- you](https://www.tesla.com/blog/all-our-patent-are-belong-you)? Just windering if it contains enough info for anyone to built a unit themselves.

<comment><USER42> The software is the special sauce. You could build your own PowerWall easily: it's just a battery box. The battery management system is the hard part.

<comment><USER43> It's not just a battery box. There's some pretty advanced liquid cooling and an inverter in there.

</comment></comment></comment><comment><USER44> Direct 1080p video link:

      https://uhsakamai-a.akamaihd.net/sjc/omega/vod/sjc-566a4ba6-8cb9-4eef-9ff4-f91aa8d13adb/84771680112000/96870994920000/plain/improved/1/chunk_NUMBER_84a103284c.flv

Replace NUMBER with 1 to 190 or get the playlist:

[http://pastebin.com/raw/YeNr726v](http://pastebin.com/raw/YeNr726v)

</comment><comment><USER45> Brilliant. Can't wait to order one. Wonder when it will ship since I was planning on reroofing next 4 months or so.

<comment><USER18> Not for a while -- he said next summer, starting in California. And all 4 styles won't be available at start.

</comment></comment><comment><USER46> How long are the batteries going to last? With phones, we expect the battery to deteriorate after a couple of years. This is an investment. Will it need to be replaced in a few years' time?

<comment><USER47> The problem with phones is that they don't have good management - the battery doesn't have active cooling, or heating when needed. They're also charged to full capacity or depleted to empty a lot of the time.

These things are what kills battery life.

<comment><USER48> Phone batteries get hot, but they have plenty of thermal connection with the environment. This is nowhere close to the magnitude of a heat problem you would have within a massive multicell pack, where the direct environment of one hot cell would be a few other hot cells. Active cooling is not something you add to a pack the size of a Tesla to make it survive a few more cycles, it needs it to survive the first cycle. But sure, once you have active cooling you might just as well try to make it powerful enough to create an environment that is even better than that of a single cell phone battery. Just don't hook overboard and have the cooling power demand cut noticeably into total cycle efficiency.

About cycle depth: Does Tesla come with an UI where you can do something along the lines of "I need to go 200 miles the day after tomorrow, do whatever you think is best for the battery in the time until then"? Or at least a setting "feel free to optimize from what you learnt about my driving patterns, except when I press the prepare-long-distance button"?

If not, most of that battery management technology will just be about not being worse than a single cell system. In that case, the difference in perceived durability mostly comes from a wildly different balance between depth of discharge and expected lifetime. Phone makers are quite happy with your batteries getting worse after two years, so they drive them over a wide voltage range, Tesla is in a market where they can't do that.

I suspect that drivers want their "fully charged" just as much as phone users, but I might underestimate Tesla/owners here. Maybe "battery wisdom" just needs some time to sink in. Sony is advertising a "top off the battery only just before the morning alarm goes off", this is the right direction (to bad that the new compact is a downgrade)

<comment><USER47> > Does Tesla come with an UI where you can do something along the lines of

No, not like that.

The charge UI interface has a 'daily' indicated range that you can set, and the top ~10% is marked 'Trip'.

Example from a screenshot of the mobile app shows what i mean[1]

The advice given to owners is to normally set the charge limit to somewhere in the daily range depending on their expected driving needs the following day.

As stated by others, it's most damaging to cells to be kept at the extremes of their charges. Controlling temperature is another big factor in it too, that's why Tesla has active temperature management in the cars and stationary storage products.

Here's real-world numbers from owners[2] and shows that the degradation even after a lot of miles and with older packs isn't terribly much.

[1] [http://imgur.com/a/Cr0Cq](http://imgur.com/a/Cr0Cq)

[2] [https://electrek.co/2016/06/06/tesla-model-s-battery-pack- da...](https://electrek.co/2016/06/06/tesla-model-s-battery-pack-data- degradation/)

<comment><USER48> Actually, that UI is pretty much exactly what I had in mind. All devices that control their own charging should have that "trip" switch. It's a shame that Android does not have an API to customize charge depth like that. I occasionally spend some idle thought on wondering how difficult it would be to overcome this limitation with a bluetooth-controlled charger. Well, I'm not an electrical engineer and "bringing the joys of self-asphyxiation to your phone" maybe would not be the most successful kickstarter ever either.

<comment><USER49> Most decent smartphones are already doing battery management and avoiding extreme draining or charging of the cells.

Think about it this way: If your phone has 8 hours of use, chances are the battery could really give you 9 or 10 hours if it was fully charged, but the manufacturer is software limiting it to prolong the life of the battery.

<comment><USER18> All things with a LiIon battery do battery management to avoid extreme draining or charging. I've never seen a phone that offered a choice of "more battery cycles vs slightly longer run-time".

For cars, it's not an unusual feature to be able to choose. The Leaf has that feature, and since it cycles its small batter frequently, it's an important consideration for owners. See:

[http://livingleaf.info/2012/07/care-and-feeding-of-the- nissa...](http://livingleaf.info/2012/07/care-and-feeding-of-the-nissan-leaf- battery/)

</comment></comment></comment></comment></comment></comment></comment><comment><USER50> The video: [https://www.youtube.com/watch?v=dRqSkR4ENAg](https://www.youtube.com/watch?v=dRqSkR4ENAg)

</comment><comment><USER51> His argument about the solar roof starts by equating the situation to how Tesla started out - electric cars were slow and ugly and needed to be sexy and cool to be attractive, and the same is true for solar. Except I highly doubt this is true here - do people really mind the look of typical roof-mount solar? My impression is that the upfront cost is just too high and cost recoup is just too slow. The argument for the solar roof is then 'using a solar roof in the first place = way cheaper than installing on top of existing roofs (and also it looks as good and works better)'.

Maybe? I'd like to see the quantitative argument here. Having a house pre- built with a fancy solar roof AND a powerpack seems like it would still be pretty much for rich people. Still, maybe the aim is for a similar trajectory as Tesla - start with a product for rich people, make it attractive, lower cost so everyone can have it and WANTS to have it.

Unrelated: gosh, I like the content of the video presentation but it would be nice if Musk was a slightly better presenter.

<comment><USER52> Every time Elon presents something we have this coversation. I for one love listening to him talk compared to say the presenters at Apple and Microsofts recent event. He's genuine, doesn't feel like a salesman, talks about the reasoning and science behind it all in a great way.

<comment><USER53> The content of his presentation is always interesting. The delivery is always incredibly awkward and cringy.

<comment><USER52> I dont agree. Not cringy and awkward, but human and real. Who cares if he stutters and doesn't bring a polished salespitch. And he's nerdy for sure, but why have it any other way. Also the few jokes thay occur are typically funny as they are genuine and not silly jokes practiced before hand like Apple seems to like.

<comment><USER53> That sounds like a false dichotomy. Recent Apple keynotes are more polished, but the content is often cringy too (that whole "courage" thing will go down as one of the most ridiculous things ever said in an Apple keynote). Not a good counter example.

But Louis CK sounds human and real _and_ he can deliver something without stuttering, bad comic timing, and awkward pauses. You might say it's his job — but that's the point. It's a job. It takes skill.

Musk is just not a good public speaker, that's all. I don't think even he would disagree with that.

</comment></comment></comment></comment></comment><comment><USER54> Sounds great, I'd like to see the assumptions in the financial model that show how it is cheaper than conventional roofing material.

<comment><USER18> Note that what he said is that the solar roof plus the electricity that it generates is cheaper than a conventional roof. The up-front cost is higher for the solar roof.

So, yes, there are assumptions in there: how much power can be generated, how valuable will it be 10 years from now, etc.

<comment><USER42> You also now get a 30 percent tax credit to replace your roof. Before, you'd be entirely out of pocket for the roof, separate from the solar install.

<comment><USER55> This is big. My roof cost nearly double what my solar installs did, and getting the tax credit on the roof might have paid for the additional cost of the solar tiles over standing seam metal. (Not that I don't love the metal; it's awesome.)

</comment></comment></comment></comment><comment><USER56> Any idea why the solar cells aren't packed more densely? It looks like there's a lot of wasted space on due to a square cell centered on a rectangular tile.

<comment><USER57> A little over 50% of a roof tile is covered by other tiles to provide the weatherproofing. The square solar part covers nearly all the exposed area.

<comment><USER56> That's not really how it looks in the pictures on their site. It looks more like they are butted together with no overlap. Also, I'd think you'd want just as much overlap on the long side for weatherproofing. This does raise an interesting question; how are they weatherproofing this installation?

</comment></comment></comment><comment><USER58> I'm interested in both but could not find any details what kind of output a solar roof would generate.

Also, I would be interested in know if it's possible to walk on top of a solar roof. People still need to be able to get on the roof to do work.

</comment><comment><USER59> Someone posted a link about Boston.gov being released as an open sourced project on GitHub. I'd like to take a moment to point out that this Tesla website is built on Drupal 7 too. The big thing that both websites get out of the box is i18n support for translation on top of all the tools required from content management. I wouldn't recommend it for websites and services that need many people to constantly update content but to build static pages that are cached is pretty awesome stuff.

</comment><comment><USER50> Musk & co changing the world one step at a time. I used to be a Tesla sceptic. Not anymore, having owned one and witnessed the relentless improvement in battery tech.

</comment><comment><USER60> Is there a summary for anyone that doesn't want to sign up?

<comment><USER10> [https://electrek.co/2016/10/28/tesla-solar-roof-powerwall- en...](https://electrek.co/2016/10/28/tesla-solar-roof-powerwall-energy- solution/)

</comment></comment><comment><USER61> Any idea how much power these things put out when compared with a conventional solar setup? 1:1? .5:1?

<comment><USER62> That was my question as well, this from the Techcrunch article:

 _" The current versions of the tiles actually have a two percent loss on efficiency, so 98 percent of what you'd normally get from a traditional solar panel, according to Elon Musk. But the company is working with 3M on improved coatings that have the potential to possibly go above normal efficiency, since it could trap the light within, leading to it bouncing around and resulting in less energy loss overall before it's fully diffused."_

Which suggests that on a square footage basis it is similar. The difference being that on a manufactured panel the cells are all exactly next to each other with no seams, and with the Tesla roof they appear to have a moat around them that varies a bit with roof tile style.

That said, assuming you cover your entire roof which will include both "ideal" south facing (or north facing in the southern hemisphere) and "non-ideal" north facing parts of the roof you may get enough additional generation from the extra tiles to push it over a more 'traditional' solar install.To be honest I'm thinking about replacing my perfectly fine (if nearly 15 year old) solar panel set up with those roof tiles. That and a couple of power walls and I just might be able to go 'gas only' with PG&E.

<comment><USER37> Normal shingles have a lot of overlap right. Wouldn't most of that moat be the overlap?

<comment><USER63> You're right. In the second tile he shows it look like 60-70% is just the moat.

</comment></comment></comment></comment><comment><USER64> "Powerwall uses an internal inverter to convert DC energy to the AC energy required for your home, lowering cost and complexity."

Does this mean that you don't need to buy a regular solar array inverter if you are deploying it with a new solar installation?

</comment><comment><USER65> A bit late to thread but;

1) I'm wondering why the tiles weren't larger? Wouldn't this make laying them much cheaper in a world where labor is such a significant cost for building. Aside from the shingle look I'm surprised these dont come in 1mx1m type sizes plus some smaller sizes for edges. I cant imaging this want discussed so curious if I'm missing some obvious logic here.

2) If you didn't have a ceiling would these let light through and further reduce electricity usage?

3) The cells seems to be a small proportion of the tile. Is this something they expect to increase so they will increase power generation ability significantly over future releases?

</comment><comment><USER66> X-post from reddit as it might get an answer here...

[http://m.imgur.com/pgskG9q?r](http://m.imgur.com/pgskG9q?r)

This LNG ship got me wondering about a battery equivalent, charged up in a desert solar farm and shipped to a major city.

I get 16 Powerpacks per 40ft container 5100 containers per Panamax ship =81600 powerpacks per ship At 95kWh per pack = 7752MWh per ship ( based on powerpack v1)

So is that like two Hinckley C nuclear reactors worth of energy? How long would that last before having to go back for recharging? How long would it take to charge from a massive solar farm etc etc. so many questions but basically, is it remotely viable?

<comment><USER67> It's not "two Hinckley C nuclear reactors worth of energy" unless you confuse MW and MWh. 7752MWh per ship = _two hours_ of Hinckley C.

</comment></comment><comment><USER68> Arbitrage economy 7 in the uk-- halve your electricity orice. Not bad at all....

</comment><comment><USER69> I was pleasantly surprised to see prices quoted in £GBP - the Powerwall is available in the UK! But, we don't have enough sunlight here to run a typical house off-grid year-round, do we?

<comment><USER9> In the UK we get about a quarter of the incident energy from sunlight in Winter than we do in Summer. You could do it by overbuilding your solar array by 4 times over what's required in Summer. That might actually be reasonable if solar prices carry on going down. Or you could do it by having some sort of micro-CHP system which produced electricity and then uses the waste heat to heat the house.

But, yeah, I think this is the major outstanding issue with renewables at the moment. Solar with battery storage looks like it will get parity with the grid anywhere near the equator, where you don't need seasonal storage. The UK needs additional solutions. I think we should be putting more money into developing micro-CHP personally. British Gas were trying out a Sterling engine system a few years back, there are also some in development using Fuel Cells.

</comment></comment><comment><USER70> I'm not following the calculations, maybe I'm sleepy. "can power a two-bedroom home for a full day". They say that is 20kWh (it doesn't change when you say sockets vs entire home...). They say the battery is 14kWh and only recommend one. Huh?

</comment><comment><USER37> @elonmusk Just a thought. How about A prebuilt shed built with these shingles might make a good product.

A lot of people buy prebuilt sheds and if it only cost $x extra and you could start lowering your electric bill.

<comment><USER64> You also need the inverter etc etc. So unless it was a big shed, maybe its not viable?

<comment><USER37> Good point. I'd imagine you could charge an electric car without an inverter. Perhaps it could be just for that purpose. Bury a line running to your garage.

<comment><USER64> Would it not make more sense to make houses DC?

</comment></comment></comment></comment><comment><USER37> Is anyone else having trouble with the tesla website? - bunch of words are in a different language and the prices are in a foreign currency.

</comment><comment><USER71> I suspect that Tesla will exponentially improve the capacity and performance of these Powerwall units every couple of years.

<comment><USER72> Exactly the reason that many people are wise to hold off on installations. The long term cost savings are wasted if future products are exponentially better in the short term. Non-financial benefits aside, naturally.

</comment></comment><comment><USER73> It looks so cute with its 110kg (220lbs)...

</comment><comment><USER74> Does anyone know where the video was filmed? It looks like it might be a neighborhood in the Bay Area.

<comment><USER75> The "Colonial Street" set at Universal Studios in Burbank, California. Most famous as the set of Desperate Housewives.

[https://en.wikipedia.org/wiki/Colonial_Street](https://en.wikipedia.org/wiki/Colonial_Street)

</comment></comment><comment><USER76> I thought Straubel said that the Powerwall was meant not for offpeak storage but for emergency backup.

<comment><USER42> That Powerwall was of a different chemistry, and has been discontinued.

EDIT: This is a baller feature:

"Always Connected: Monitor your solar energy use in real-time and _receive alerts when Powerwall is preparing for cloudy or severe weather._ "

They're performing weather forecasting, and then ensuring the Powerwall has charged up for a possible outage event. Brilliant.

<comment><USER32> I cannot imagine what preparation they could be making. Surely the default process is to charge the powerwall at all times if feasible. What extra operation could it do in the event of a bad weather forecast? Other than tell you about it.

<comment><USER77> To get better lifetime out of the cells, you don't fully charge them. I bet when bad weather is occurring soon, it charges to maximum storage capacity, not to max cycle level.

This lets you have best of both worlds, with a minor tradeoff in unpredictable outages you have slightly reduced runtimes.

</comment></comment></comment></comment><comment><USER71> I'm very impressed by the solar roof shingles, especially the French slate style.

</comment><comment><USER78> As much as I like the idea after reading about the Note 7 and then a battery fire at DARPA I'm not fond of a giant battery lithium-ion battery in my house.

<comment><USER79> The problems with those batteries are that cell phones pushed the limit such that they were dangerous due to thin walls between part of the battery(ies), and hoverboards didn't keep batteries from overcharging, which causes a chemical reaction forming spikes that penetrate the thin walls between the parts of the batteries that cause fires. The batteries tech itself is not a problem; it's the design around it.

And if you think this is bad, just wait until batteries get more powerful and there are problems. Be thankful that it only starts a small fire!

</comment></comment><comment><USER80> Correct me if I am wrong, it estimates 12,000$ for a single day of energy backup of your home? For 12,000$ I dont mind staying one day without electricity.

<comment><USER81> If you generate more electricity than you use during the day, you all of a sudden don't have an electric bill... or a drastically reduced one.

The funny thing about solar... it's not constant. Half the day is night... then clouds/rain/etc. 24/hours of electricity is for those dry periods.

<comment><USER80> But my electric bill is like $30-40/month, Why would I want to shell out $12,000 for something that will become old tech in couple of years like the 1 powerwall.

<comment><USER82> 30-40$ is probably a very small apartment. A house (2 levels) in Quebec during winter can go easily around 500$ because of the constant heating required.

<comment><USER80> But you won't get much solar electricity during winter in Quebec anyway would you?

<comment><USER83> Cooling a house during the summer in Texas can easily cost the same amount if not more, and you get a ton of sun during that time. The point is that for single family homes electricity does not usually cost $40/month.

<comment><USER80> But the price for the equal amount of power walls needed for a bigger house vs a small 1 bedroom raises too, according to the calculator on their site it will cost $30k+ to install it for 4 bedroom house.

</comment></comment></comment></comment></comment></comment></comment><comment><USER84> Are the solar cells and powerwall shielded by any kind of solar storm? I couldnt find any detailed information confirming or denying it. I would not like for any of us to be in a situation where the 1st solar outtage is our most damaging, and thats what causes any producer of electronics to adopt labeling and marketing for it.

<comment><USER85> Radiation spikes caused by solar storms

1\. Are not in the visible spectrum

2\. Do not reach the earth surface in appreciable amounts

</comment></comment><comment><USER86> You can buy 12v 250ah deep cycle AGM batteries from China for around $5 per battery -- lets assume another $15 for world-wide shipping. These kind of batteries would have around 3kwh of storage per battery but since you shouldn't discharge them to more than 50% lets also say that you need to double the number of batteries to achieve 14kwh of usable power for 28kwh of total capacity. At that capacity level, you would need only 9 batteries for a sub total of just $180 USD (including shipping.)

Lets proceed with these calculations and say that you also want a good quality "grid-tie" "pure sine wave" inverter (to feed your stored energy back to your home grid) which will set you back any where from $100 - $1000. Your total cost for energy storage is still only going to be around $1180 (worse case.) Now consider that the life time for the Tesla batteries and standard AGM batteries seem to be very similar and I honestly have no idea what the customer is actually paying for.

Is the compact size and sleek appearance really worth the extra cost to the customer? Maybe it is. Maybe people don't want to have a nerdy battery bank in their homes but to me the benefits all seem a little petty. (Granted, I definitely do see the benefit for tech like this in electric cars though, don't get me wrong.)

<comment><USER87> And once your self made cheap chinese battery pack ends up catching fire and taking your whole house with them you understand why you want to pay for some actual company to do this and have some quality control/insurance.

<comment><USER28> Yeah because Lithium Ion batteries never catch fire.

</comment></comment></comment><comment><USER88> So I used the calculator on Tesla's web site, in my case, I'd want 3 powerwalls and I'd want a solar installation to complement it: $18,000 USD.

That's still way too high: $1,800 - $2,500 would have been acceptable. That is how much I'm willing to pay for some solar panels, three batteries, and a little bit of electronics (processed sand) to control the lot.

As far as I'm concerned, this is all still hype. Prices need to go down, waaayyy down, and the profit margin and the engineering needs to be recuperated through volume. The days of fat profit margins and the early adopters amortizing the research and development have come and gone. The computer industry learned that lesson the hard way; it would be a shame if Mr. Musk repeated the same mistake, instead of learning from history.

<comment><USER89> A more interesting metric might be months of pay back time. $1,800-$2,500 seems like an arbitrary number you made up.

Like if your power bill averages $150 (I realize it probably doesn't) and you plan to stay in place for a few years, then something like 50*$150=$7500 is easy to consider and is much higher than the numbers you tossed out (that's just over 4 years to pay you back).

I mean, I agree with the point you are implying, that people won't be overwhelmingly excited with solar until the payback goes below 2 or 3 years, but I think it also makes sense for longer payback times.

<comment><USER88> _A more interesting metric might be months of pay back time. $1,800-$2,500 seems like an arbitrary number you made up._

It _is_ an arbitrary number I made up!

Which part of _that is how much I am willing to pay_ requires additional clarification?

 _I mean, I agree with the point you are implying, that people won 't be overwhelmingly excited with solar until the payback goes below 2 or 3 years,_

That's exactly right, and more: I am _not willing to amortize their research and development costs outright_. That's something Tesla (or any other company, for that matter) will have to do over years, at least as far as _my wallet_ is concerned. Amortizing research & development costs outright is just pure greed; I won't support it.

<comment><USER89> _It is an arbitrary number I made up!_

My point is that this is not really a good way to make financial decisions. If you've bought a house and plan to stay, spending up front to save over a decade is something to work at. Consider the rule of 72. Something that pays back in 10 years is yielding a roughly 7% return. That's a great return. As I said, I'm right there with ya on waiting until it makes good financial sense to make such purchases, I just think it is also a good idea to do some analysis to figure out what that means (and if the purchase makes sense, who cares what it means to the company selling).</comment></comment></comment></comment>