Tesla Energy - <AUTHOR> http://www.teslamotors.com/presskit/teslaenergy <comment><USER4> What I'd love to see is a ROI calculator that:

* uses my zip code to figure out what my non-peak costs might be.

* allows me to optionally calculate solar energy capture (so I can see what impact having solar would be, given the average sunny days in my area)

* takes into account the wear and tear average cold weather would have on the lifetime of the batter and the payback period.

For example, I live in Michigan, and I don't know what my off peak cost is off the top of my head. I also have no idea how much sunshine I get, or how 10 degree lows for two months would impact the battery's ability to keep a charge.

Anybody know if something like this exists?

<comment><USER5> I would guess for most people it would show an ROI number that is not conducive to sales.

Also, what is the environmental impact of the manufacture of LI batteries at this scale? Lithium mining, processing, assembly, delivery... we can't just ignore that.

<comment> at-fates-hands I agree.

Strangely, all of these issues were conveniently left out of the article.

Not sure everybody knows this, but its not economically feasible to recycle these batteries:

 _" Recycled lithium is as much as five times the cost of lithium produced from the least costly brine based process. It is not competitive for recycling companies to extract lithium from slag, or competitive for the OEMs to buy at higher price points from recycling companies. "_

Add in the fact there are currently very few dedicated LI recycling companies in the world, let alone in the US:

 _" With lithium recycling in its infancy, there is currently no main recycling infrastructure in the world that treats only automotive Li-ion batteries. A few pilot plants, such as Umicore's Hoboken plant in Belgium that are at a demonstration stage exist. Lack of standardisation in battery chemistries and changing landscape with respect to different elements under research for battery production other than lithium have made evaluation of the recycled value of the components uncertain for the recyclers."_

source: [http://www.waste-management- world.com/articles/print/volume-...](http://www.waste-management- world.com/articles/print/volume-12/issue-4/features/the-lithium-battery- recycling-challenge.html)

Call me skeptical, but I'm not sure Tesla has really given consideration to these issues. Their approach to these obvious issues are not addressed at all in their press release.

<comment><USER6> So I recently needed a special cable to make some old gear work. It was only available from a single source and they charged me an arm and a half for it.

Why am I telling you all of this? Because the price of something has very, very, very, very, very little to do with how _feasible_ something is, how much work is required on a _fundamental_ level.

So what? Recycling lithium isn't profitable _right now this very instant_? Because _the price_ is too high? Apart from the circular logic here, this means nothing.

(This kind of thinking is disappointingly common here. We will never get anywhere when we do some adhoc "price" analysis on every new technology and obviously deduce it's infeasible and should not be explored. Cars were _economically infeasible_ back when you bought petrol from the pharmacy.)

<comment><USER7> Yes. Thank you. I wish I could upvote your comment more than once.

</comment></comment></comment></comment></comment><comment><USER8> Funny that something called Tesla Energy brings back direct current to the home. I wonder how many people will catch that.

<comment><USER9> I wonder if technology becomes prevalent if we will see appliances change to run on DC.

<comment><USER10> I would take a wall plug standard for low current DC. If I have a giant battery pack in my garage full of DC, why do I need to convert it back to AC to run 15 feet into my house where it then gets turned back into DC to charge my phone & laptop?

I had a boat with both AC & DC sockets, but we had the normal socket for both and the label plates showed you which was which. I don't think that solution is acceptable for the wider marketplace, the plugs should probably be physically distinct. Maybe USB-C is the solution, though I don't know how long the cables can be.

<comment><USER11> From an efficiency standpoint, the only thing that matters is how you handle the high drain equipment. It doesn't make sense to worry about inefficiencies in your 5V phone charger because its power draw is trivial anyways.

<comment><USER12> oh but think how much nicer the cable looks without the bulky box of the transformer.

</comment></comment></comment></comment></comment><comment><USER13> Nice, that came in lower than I was expecting. I was thinking $5K for the 7kWh unit. Of course that is the "installers" price so who knows what those folks will consider the 'retail' price. My wife still has her solar installer certification so we could presumably get one that way.

It also makes for a really interesting opportunity for grid tied solar inverters. Now you want the inverter to power the house first, then push power to the batteries and only if they are full push it back to the grid. Software update for sure :-) of course it might make more sense to leave it DC for the push into the battery and only have the AC conversion happen post battery, so charge controller between the battery and the DC disconnect.

On a safety note I'd also really like to mount this outside, preferably against firebrick rather than my house. I realize the batteries are much safer than they have ever been, but still a cascading lithium battery failure inside my garage is not my idea of a party

<comment><USER14> On the grid tied solar inverter front - the spec sheet says the battery voltage is 350~450 V, so we're looking at 108 lithium ion cells (25 x 18650 cells?) at 400 VDC nominal. This is quite different from typical lead acid battery pack voltage of 12, 24, or 48VDC that's used for battery backup storage, so a lot of existing solar battery storage infrastructure may not even work... this means that people may need to buy a whole new set of supporting hardware to integrate this into the existing solar systems instead of being able to update the software on existing hardware.

Lithium Ion also has quite a different (and much less forgiving!) charging cycle that requires much more monitoring of things like temperature, though I'd imagine a lot of that would be built-in as a safety mechanism directly into the Powerwall.

What I've heard is that National Electrical Code becomes much more stringent on battery systems greater than 48V, with the line drawn at 48V due to it being used widely in the phone landline system. I'm not sure how true that story is, but I'd imagine extra care is probably warranted. 10kWh is about 9kg of TNT. :-)

<comment><USER15> Yes talk to telco Engineers from the power side of the biz and they will have war stories about accidents and close misses with the Central Offices (Exchanges) DC power.

High Voltage/Amperage DC is quiet different to AC power and i suspect that building/wiring codes are going to need to be updated if this local storage takes off.

<comment><USER16> dropped a wrench across the terminals on the deep cycle backup batteries inside a telco switching center. Had to disconnect the whole bank of batteries to fix it because the wrench welded itself to the terminals. it wasn't a tack weld either.

<comment><USER15> The one I remember is decorators placing a paint tin across the bus bars - which explosively painted the walls

</comment></comment></comment></comment></comment><comment><USER17> This is a three-pronged stroke of genius:

1) Immediate benefits to just about anyone. If you have your own solar panels, you need this (or something like it). Even if you don't, you can benefit by drawing more power during cheaper off-peak times.

2) If lots of people get in on this, we'll have the storage capacity we need on the grid to be more dependent on renewable energy. Lack of storage capacity is one of the biggest obstacles to increasing renewable generation.

3) If lots of people buy this, the price per unit goes down, and it's the most expensive component of Tesla's main product, their cars - which are effectively batteries on wheels.

<comment><USER18> > power during cheaper off-peak times

Pretty sure my rate is the same all the time. I wonder what percentage of electricity customers have variable rate pricing.

<comment><USER19> NYC has it now, but I think as generation/fuel prices rise (in the long-term) and utilities get slightly more sophisticated, we're going to see more on- demand pricing as utilities seek to apply the same price changes they pay generators for peak-demand supply to consumers.

In a situation where many people were doing load shifting, I think this could even benefit those who aren't doing load shifting themselves (by reducing peak demand across the network).

<comment><USER20> For each person that load-shifts, it slightly reduces the payoff for the next person to load-shift.

In the UK, the peak demand is already in the evening[1], because solar has eaten the cheap lunch during the day (which it was supposed to do, but it means that each additional solar panel is going to have a harder job paying for itself). And the demand difference between low and high is about 30GW to 40GW.

[1] [http://www.gridwatch.templar.co.uk/](http://www.gridwatch.templar.co.uk/)

<comment><USER19> Great point about marginal benefits of load shifting. I do think we're so far from that reduction being significant at this point that it's worth attempting.

I believe peak demand in most non-industrial areas is already evening, because residential areas tend to have less efficient energy use than commercial spaces due to density, and everyone is home at the same time, often doing energy intensive tasks such as cooking, using the A/C, opening the fridge. I heard from someone at a power company that advertisements during the Super Bowl are a major issue, because everyone opens their fridge and flushes the toilet at the same time, and power supply has to spike for 3 minutes and then return to normal.

</comment></comment></comment></comment></comment><comment><USER21> One thing that might go overlooked: Load shifting could, in theory, lower electric bills such that there's ROI without solar panels.

\---

Edit for why: On-demand power is expensive. "Spinning up" additional power during the day is more expensive than having certain types of power generation running all the time. In theory, pumping power into a battery at night during non-peak hours will cost less than consuming directly off the grid during the day.

I'm forgetting all the details of energy economics, but IIRC there would also be far less emissions by having consistent load on the grid all day long. Something about the ones we "spin up" also being the worst for the environment.

<comment><USER22> If what you say is true, then with better economies of scale and longer investment horizons, utilities would quickly erase any peak-vs-non-peak arbitrage opportunities.

<comment><USER21> It's hard to wrap your head around all the challenges in energy. If you're REALLY good at it you can find some incredible arbitrage opportunities...see Enron.

Consider the power output characteristics of some common energy sources:

Gas, Nuclear, Hydro, Wind, Solar

Our "sustainable" sources of power - hydro, wind, and solar - are also the ones with the most irregular and unpredictable power output. This creates a problem, because even if there was enough cumulative power output from sustainable sources today, it most likely wouldn't align with our usage schedule.

So there are two solutions: 1) find a way to map the sustainable power output to our usage 2) find a way to store energy

Today, our most readily available form of energy storage is gas. We just put it in a container and burn it when we need to. "Spin it up," if you will.

An alternative to gas is a crazy network of Powerwalls. The hope is that, eventually, instead of spinning up gas turbines during peak demand, we can just draw from our Powerwall.

There was another alternative on HN recently. Basically a super-deep hole in the ground with super heavy object falling into it, but suspended by a rope. You run a motor to lift the object during off-peak hours, then let it fall and spin a generator during peak hours. I can't find it right now but I remember thinking they had a great name.

\---

That said, power output is only part of the problem. If you're looking to factor the potential disappearance of arbitrage opportunities into your buying decision, you also need to consider the time until regulatory changes allow for perfect pricing, and the time until these Powerwalls have precise enough information to decide exactly when to draw from the grid versus the battery.

tl;dr: "quickly" is probably optimistic. We're a long ways away from economies of scale.

<comment><USER23> was it a gravity battery?

</comment></comment></comment></comment><comment><USER24> (Posting from my phone after the event). If you are excited about this and want to work on it then please email me at firstname.lastname@example.com. We are very excited about the technology and future!

</comment><comment><USER25> $3,500. That's crazy good for your average household, on par with natural gas backup generators with half the logistics. I might just be ordering sooner rather than later given some of the grid instabilities in my area over the past year, and through the mid-term in preparation for a solar switch here in Chicago.

While Elon might not be the best orator, you can easily derive his authenticity and belief in the product by virtue of his delivery. You can't do that with accuracy in the canned and carefully rehearsed.

<comment><USER26> $3500 doesn't include the inverter or transfer switch. Transfer switch is maybe $200, and it's not clear what the inverter might cost. It's a nontrivial part, since it would be responsible for daily cycle estimation and cost optimization.

For $3300 you can get a 17 kW generator with inverter and transfer switch [0], which will run for days on a house-sized propane tank. At my house in the woods, we do sometimes get multi-day power outages after storms. Though, to be fair, you need a concrete pad and 30 square feet to install the generator.

It doesn't seem like a competitive backup system, but load shifting is still appealing.

[0] [http://www.costco.com/Honeywell-17-kW-Automatic-Standby- Gene...](http://www.costco.com/Honeywell-17-kW-Automatic-Standby- Generator.product.100144364.html)

<comment><USER27> Some people (like me) are simply unwilling to keep using carbon-based sources of energy. At some point it just feels awful to be contributing to such a terrible problem. I'm counting the days till I can sell my worn out petrol car and get an electric car. If I had a home and dollars, I'd want one of these batteries.

<comment><USER28> Batteries are not clean; lithium mines are one ugly slight and recycling is difficult: [http://whenonearth.net/awe-inspiring-aerial-images-worlds- me...](http://whenonearth.net/awe-inspiring-aerial-images-worlds-mega-mines/)

In my clueless opinion these batteries should be used strategically in places where solar, wind, and hydro power are unavailable.

<comment><USER29> Yes the real breakthrough tech needed is a new battery! Which hopefully Tesla is on track to develop,because as is, electric cars are just not scalable.

<comment><USER27> People say that, but from what I've heard there is plenty of lithium in the world to increase use 20% every year for 30 years before we need to get more creative in how we mine it. That's a huge total increase and means that electric cars totally are scalable.

Do you have information supporting the idea that electric cars aren't scalable? My understanding is that they definitely are scalable.

<comment><USER30> Charging is where the scaling problems come in. If everybody in your neighborhood plugs in their Tesla at their home at night and/or at their office during the day, it will likely cause brownouts and blackouts in areas with grid service that's already marginal for current demand. Hence Musks's interest in load-shifting technology.

<comment><USER31> it isn't so much how many people charging, its the ability of people to charge where they live and the lack of ability to truly quick charge the battery.

As in, damn the kids left the car unplugged and I have to work. even thirty minutes at a super charger is not a good solution.

So it comes down to a compromise, a good range extender technology and batteries for the majority of driving. That until truly faster charging can be achieved with house hold wiring.

<comment><USER32> > _As in, damn the kids left the car unplugged and I have to work. even thirty > minutes at a super charger is not a good solution._

I don't see this as something to worry about - it's just a household habit problem. Pretty much every new device introduces some, and people quickly adapt to use the device properly.

<comment><USER33> The argument is silly. The kids could also forget (or just not bother) to put gas in the car and leave it on empty. Yet strangely we manage to make do with gas-powered cars.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER34> The competition doesn't sleep: [http://www.greentechmedia.com/articles/read/sungevity-and- so...](http://www.greentechmedia.com/articles/read/sungevity-and- sonnenbatterie-to-undercut-tesla)

In fact they seem to be ahead. Sonnenbattery offers [http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery](http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery) since 2011 in Germany.

For technical details see [http://www.sonnenbattery.com/strom-energie- speicher/sonnenba...](http://www.sonnenbattery.com/strom-energie- speicher/sonnenbatterie/technical-data/)

<comment><USER35> The article has been updated as the price is $3,000 and not the predicted $13,000.

</comment></comment><comment><USER36> Questions:

1\. How is this different from a UPS? (Similar capacities can be obtained for less money.)

2\. How many cycles can we expect to get out of these? (One assumes these are designed to be cycled more often than a UPS)

3\. What are the risks when temperature is outside the operating range? (If non-negligable, the stated operating range of -20C to +43C limits use in some applications, such as field stations without heating (or AC, depending on locale).

4\. Is this technology viable on the scale of an entire powergrid? If it's advantageous for individual users, one would think economy of scale would make this more efficient to implement grid-wide.

5\. Do these present an additional hazard in the case of fires, floods, etc.?

</comment><comment><USER37> A notable beta user:

AWS will be running a 4.8 megawatt hour pilot program with Tesla's batteries in the us-west-1 AZ (Northern California).

Hopefully this allows AWS and other hosting providers to use intermittent, renewable sources of energy more often.

EDIT: I'm guessing AWS will be using a cluster of 48 power packs (100 kilowatt hours each).

<comment><USER38> This might be a reason to move your production environment out of us-west-1 for a few years.

I wouldn't want any experiments going on around my main servers.

<comment><USER39> If you don't want experiments going on around your servers you better host them in your own data center. Amazon is guaranteed to be running many experiments in all of their data centers (and not just with power, with the actual server hardware!).

</comment></comment></comment><comment><USER40> This was offered to SolarCity customers in late 2014, I see that the image here [http://www.solarcity.com/residential/backup-power- supply](http://www.solarcity.com/residential/backup-power-supply) now reflects Tesla branding.

<comment><USER41> Iinteresting how they are branding it as a backup solution, while Tesla is branding it as a complete replacement.

 _" What if we could move the electricity grid off of fossil fuels"_ (Tesla)

vs

 _" Be prepared the next time the power goes out."_(Solar City)

<comment><USER42> "Models

10 kWh $3,500 For backup applications

7 kWh $3,000 For daily cycle applications"

From [http://www.teslamotors.com/powerwall](http://www.teslamotors.com/powerwall)

Maybe Solar City has been using the ones meant for daily cycle - that would make sense.

</comment></comment></comment><comment><USER43> Doesn't include inverter or installer markup and can only provide 2kW output.

It will get expensive by the time you actually have all the bits you need inside your house.

How is this better than deep-cycle batteries (with 20+ year lives) again? Why does it need to be slimline?

<comment><USER44> "and can only provide 2kW output."

 _only_ 2kW? 2kW is enough to power any residential, single-family house for 95-98% of the time; you only need (a little bit) more than that at very short (few minutes) peak intervals - when heating up an oven, or some cycles of doing laundry. A second unit would provide that headroom, and otherwise (when the extra $5k for a second unit is prohibitive) you could still draw from the grid for peak loads and just not run an oven and washing machine at the same time during grid blackouts.

It does require a 21st century house - led lighting (but it's 2015 - who still uses incandescent except for those places where you don't turn on the lights more than 4 times a year anyway?), energy-conscious appliances, moderate need for A/C (sane insulation and ventilation, localized and intelligently controlled A/C needs - i.e. no 'bring all room in my 3000 square feet sheet rock and tin roof house down to 75 degrees when it's 110 degrees outside'). But whoever doesn't have that, has options to start reducing their bills that are much better than buying energy packs.

<comment><USER45> I use incandescent lights. They produce a much more pleasant spectrum than "white" CFLs or LEDs.

<comment><USER44> LED's are available in various color temperatures, including 2700K (commonly referred to as 'warm white' which is basically the temperature of incandescent). It's true that the dollar-bin Chinese LED's have all sorts of bad characteristics that used to be associated with all things LED - <USER2> color, bad spread, bad (or no) dimming capabilities, etc.

It's 2015 though - take a 20$ Philips Master LED for example (I decided upon those for myself so I looked into them more heavily; I have about 20 in use now, with another few boxes in my basement awaiting installation). The GU10 socket halogen-replacement version is available in 3 temperatures and 3 spread bundles, has a 20k burn hour rating (vs 1-2k for incandescent!) and can be dimmed very well using a 50$ leading edge electronic dimmer.

I'm no tree hugger - even purely economical (apart from the convenience of not having to replace lamps every year), in 2015 it doesn't make any economic sense to buy incandescent (in those places where it's possible to buy them at all...) for all purposes where the light is used on a 'regular' basis (more than an hour a day or so).

Of course it does require an initial 'investment'. But one that would be spread over 1 or 2 years - the normal replacement cycle of incandescent bulbs. Throwing out working incandescent bulbs to replace them with LED is not rational either, of course.

<comment><USER46> Color temperature is nowhere near everything. Or rather, it would be, were LEDs actually anywhere near a blackbody in terms of radiation output over the visible spectrum. But they aren't. Nowhere near.

<comment><USER44> There is no every-day use case where the difference in light perception from an incandescent bulb is different, or even distinguishable without measurement, from an LED bulb. Feel free to try it yourself in a light studio, or otherwise, please cite any studies with modern lamps that conclude that the 'light quality' (by whatever metric) of an incandescent bulb is higher (that is, 'higher' as in 'makes a material difference for normal use cases', not 'in the lab using our spectrometer we measured a difference').

As always, there are people (analogous to 'vinyl produce a richer sound' idiots) who have 'opinions' on light quality, but well, we all know what they say about 'opinions'. In 2015, it's plain nonsense to take 'light quality' as a reason not to use LED light for domestic purposes, full stop.

<comment><USER47> The subjective experience of a home lit with incandescents is very different than one lit with LEDs. I don't care if the color temperature is the same. Things just look different. The bulbs cast their light differently.

There may not be a difference in "light quality", photons are photons, but if you convert a home from one to the other things will look different, and you may prefer one way or the other.

And don't forget about fixtures that were designed to work with clear incandescent bulbs for aesthetic reasons. LED bulbs will look downright hideous in those even when the lights are off.

There are people who like how vinyl sounds better because they like the hiss and the pops, not because they fall for audiophile silliness. The same holds for lighting.

<comment><USER48> Yes, but being unwilling to spend 1 day adjusting to a different look is a pretty silly reason to continue to run a bunch of spaceheaters in your house that, as a byproduct, happen to produce some light.

Particularly if you ever use air conditioning.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER49> Live Stream:

0\. Tesla will open source its patents for the Gigafactory.

1\. Elon thinks all the world's energy needs can be served with 2 billion Tesla GW powepacks.

2\. Elon: "This is something we can do, need to do and should do."

It's over.

<comment><USER50> Tesla doesn't own most of the patents related to the Gigafactory. They're licensing the battery technology and manufacturing techniques from Panasonic.

</comment></comment><comment><USER51> I have four rack-mount uninterruptible power supplies that provide battery backup to my workstations and servers in my house. My curiosity here is whether this Tesla battery pack will obviate those UPSs, providing automatic and immediate in-line switching to battery whenever there is an interruption.

That alone would be compelling at this price.

Edit: Incidentally, when I submit the reservation form, there is no confirmation.

<comment><USER52> That would be determined by the inverter, not the batteries. And yes, almost all grid-tie inverters will serve your load with a switching time fast enough that computer equipment would continue running.

</comment></comment><comment><USER53> The wall mount surprised me, but 10KWh at the same density as the Model S battery should be only 155lb. That's not too bad, although you need a solid connection to the building structure. Having it above floor level is a good thing, since it won't be shorted out by minor flooding.

If you get a new solar installation, installing one of these seems an obvious win. The solar installation already includes the inverters and control gear. Without solar, it's probably not worth the trouble for residential.

The average American house uses 30 KWh per day. If you have daily sun and a low nighttime air conditioning load, 10KWh should get you through the night. Hawaii - perfect. Southern California - looks good. Texas - get two to get you through the night with A/C.

<comment><USER54> As I've learned more about heat pumps I've been wondering why we all use air- source cooling for central A/C. We are cooling our condensers with hot summer time air when the temperature is much lower just four feet under the yard.

The energy requirements would drop way down by cooling the condenser with a water ground loop.

Ground loops are seen as expensive for installation, but I don't understand why. It's just plastic tubing buried in the yard. I've been wondering if a hole digging robot could lower the price. The carbon and money savings would be huge if we could bring down the cost of ground loop installation.

<comment><USER55> I very briefly looked into this. It seems to be the same reason that simple and obvious things like solar water heating systems are so expensive in the US, but not elsewhere: Lack of awareness & low demand but few installers who target the eco/luxury niche product at a high price. These systems usually get installed only in high-end homes.

<comment><USER53> Climatemaster has about a million US ground-heatsink heat pump installations. In their system, the ground loop is water with antifreeze, not Freon, so there's an additional heat exchanger.

Rheem, the big water heater manufacturer, sells solar water heating systems. That's progress; previous solar-only sellers were kind of flaky. (See "hot2o.com", which disappeared.) Solar water heating systems have a reputation for leaking. Buying something that is supposed to last 10-20 years from a small company is a problem.

</comment></comment></comment></comment><comment><USER56> I am just going to cut and paste my previous comment on Musk.

The Musk M.O: 1\. Identify industry with big inefficiencies that depends on huge government subsidies. That's cars, commercial space vehicles, mass transit and now: colonizing another planet with the 0.1%. 2\. Convince the media and envious government officials you are Tom Swift, boy inventor. Have these governments fight over how many billions to give you to build your space car factory. 2\. Use these taxpayer dollars and gigantic tax breaks to create iconic products and services for the elite class, effectively transferring huge dollars from the poor to the rich. 3\. Rinse and repeat.

I see no evidence at all that Musk cares any more about technologies to enable several billion of us to live together without slaughtering each other than he does about money.

Add the utility business to the growing list of government supported industries Musk wants to "disrupt" by which I mean establish a publicly funded, government subsidized mechanism to siphon off dollars for himself, just like Tony Stark in fact. The electricity generating and distribution system is one of the most provably useful "common goods" in the history of the human race-- why not convince people to spend more than 10 grand to power their house for 24 hours?

His reasons:

Load Shifting - residences generally have NO economic incentive to ride the demand curve, only businesses do in some cases. It is one of the most important things about the electrical system--these huge monopolies manage that curve collectively for us. Sure, transmission is inefficient, but so is decentralizing that task, while adding the risks of keeping your battery from breaking/catching fire.

Increasing self consumption- a battery does not stimulate this at all - <USER3> grid needs your power most when the sun is shining. Solar power and an inverter provides that incentive today.

Backup - One day of power in the event of a true natural disaster for $10,000 is expensive and not sufficient.

I am not a Luddite and I am a libertarian, and certainly our society needs technology visionaries right now, but I find Musk's increasingly cynical ploys and the adulation they receive pretty annoying. They seem designed to distract from the overall failure of his businesses, even if he continues to generate ideas and hype.

<comment><USER57> Your comments on his reasons are clearly counter-factual:

Load shifting on a consumer scale has been happening for decades in various places around the world (e.g. cheap nuclear energy at night powering storage heaters)

Self-consumption: in a grid increasingly fed by solar power all those peaks hit at the same time and there's been multiple recent news stories about power prices going negative at those peaks.

Backup - no-one said anything about "true" natural disasters. Backup from short power outages is already an established market in many outlying areas and a fringe benefit for almost anyone. And no-one said that you had to buy it and use it for this single purpose.

This whole area has been predicted as a growing market for years, there's others in this thread complaining that it's nothing new compared with less famous competitors, so complaints that it's a product dreamt up to soak up subsidies is a bit odd.

Having said that, if I was in charge of a government, I'd be subsidising these kinds of decentralised grid backup right now as they are already useful when viewed at a national scale. It seems likely that in a few short years they'll make economic sense for more and more people without any subsidy though.

<comment><USER56> Not at all trying to pick a fight. But:

>Load shifting on a consumer scale has been happening for decades in various places around the world (e.g. cheap nuclear energy at night powering storage heaters)

Sorry, but as a consumer I pay the same rate day and night, and I think most in the US are like me. I personally have no incentive for load-shifting. Why do I need PowerWall?

>Self-consumption: in a grid increasingly fed by solar power all those peaks hit at the same time and there's been multiple recent news stories about power prices going negative at those peaks.

Solar, including concentrated solar which is outside this discussion, is currently 0.48% of all US electricity generation. Not a big effect for many years, unless one of the other Musk businesses (Solar City) gets a big boost.

>Backup - no-one said anything about "true" natural disasters. Backup from short power outages is already an established market in many outlying areas and a fringe benefit for almost anyone. And no-one said that you had to buy it and use it for this single purpose.

Okay, but it seems like a pretty expensive way to ride out a few hours of blackout.

> This whole area has been predicted as a growing market for years, there's > others in this thread complaining that it's nothing new compared with less > famous competitors, so complaints that it's a product dreamt up to soak up > subsidies is a bit odd.

I've been called worse, but my point here is that these predicted schemes haven't taken off because they would depend on MASSIVE subsidies, and Mr. Musk does dream big.

The main point is that everyone should probably have a battery in their garage, but that battery should be in a car, and since business is not working out so well for Musk he is trying to access another source of regulated government support. The economics/policy of electric cars seem much better than home electricity storage, and all the benefits of PowerWall, if they materialize, can and hopefully will be delivered by lithium under your hood. Battery-powered cars will take over America, I just doubt most of those batteries will be made by Tesla.

<comment><USER33> > _Sorry, but as a consumer I pay the same rate day and night, and I think > most in the US are like me._

Where do you live? I pay the same rate 24 hours/day as well, but I could switch to a plan with different rates if it provided value to me. I suspect most power companies provide the option at this point.

> _Okay, but it seems like a pretty expensive way to ride out a few hours of > blackout._

Is there actually a cheaper option, aside from sitting in the dark with flashlights and making sure that no one opens the fridge or freezer? If you want to ride out a blackout without basically sitting in the dark, you need either a big battery backup or a generator. My in-laws put in a whole-house generator and I think the total cost was nearer to 30K than 3K. (Edit: Actually, just looked at generators and they seem closer to 3K, so I have no idea why their setup would have cost nearly 30K. Edit2: They probably installed something closer to a 25kW generator, which would explain much of the cost.)

> _The economics /policy of electric cars seem much better than home > electricity storage, and all the benefits of PowerWall_

A battery in my car will spend a large chunk of its time somewhere else. It's in intriguing idea to use the car battery this way, but it means when I take my car out, my backup power is gone. If I have solar panels, it also means my daylight charging is also gone (assuming I'm gone, with my car, during the day). So I think this would be great, but would not obviate most of the value of a home battery.

<comment><USER58> With respect to blackouts, I guess it depends on what's the typical pattern where you live. If it's a short outage (<= few hours), my personal reaction is "who cares?" The main one I worry about, living in the Northeast, is an extended outage in winter that could result in frozen pipes. Spoiled food due to an extended outage in the summer would be annoying but that's a much more bounded cost associated with a rare event. And a battery probably wouldn't last long enough to help in a > 24 hour outage situation--which is when protection would be needed.

I agree that $30K sounds like a lot for a generator. I periodically think about looking into it; I've never seriously priced the whole thing out-- generator, connection to house, installation, enclosure--but my expectation us that it would be less than $10K. In such an event I certainly have no problem minimizing my electricity use so long as there's enough juice for the furnace in the winter and the refrigerators.

I'm not aware of an option for non-fixed rate electricity where I live.

</comment></comment></comment></comment></comment><comment><USER59> This is much more groundbreaking than it may appear. The innovation is entirely in the price.

At $3500, you can put in two and be entirely off grid. Solar panels are cheap enough you only need batteries to last one night, as you can size the array to operate your loads even on cloudy days.

<comment><USER43> 2 is not enough. 4kW seems to be the maximum potential drain from the battery. That wouldn't power an oven… let alone anything else at the same time.

4kW inverters seem to be around the $1000 mark… but they don't seem to increase linearly (10kW inverter $4000 for example).

Of course you could go totally off-grid, but the cost isn't going to be just $7k… it's likely to be at least $15-20k by the time you get everything you need and installed. At that price, you could've bought a larger capacity deep- cycle storage solution already readily available on the market with batteries that will last 20+ years.

<comment><USER44> " 4kW seems to be the maximum potential drain from the battery. That wouldn't power an oven… let alone anything else at the same time."

4kW is enough to power an entire home continuously, without thinking about energy use, even a large one with a home office with several people working in it + washing machine + oven + electrical stove _at the same time_. I have the data to prove it, too - 10 second interval power consumption logs for the last 4 months for my house/office, and I never had a load of more than 3.5kW. To be fair, this is all with modern, top of the line appliances, so yes that 199$ no-brand Chinese oven will probably draw a lot more power, but still.

Worst case, you'd need a second 'peak power' supply, which could provide e.g. 6 or 8 kw for 10 mins max, maybe using some sort of XXL capacitor. I don't know about the EE side of this, or whether such a thing exists already, just saying - 4kW is perfectly feasible and even heavy users would maybe need just a little bit more.

(of course this also assumes you have a better quality house than the standard American cardboard 'house' in which you need A/C running 24/7 just to not die in summer).

<comment><USER60> My air conditioner is 12 kW. No chance.

<comment><USER44> If your air conditioner actually draws 52 amps at 230 volts (or 110 @ 110 if you're in the US), you must be air conditioning a gym hall with a black, tin roof somewhere in a desert.

But you're probably not, and that was my whole point - my stove top is rated at 10kW, too, yet _even when using alongside all other appliances in my house_ I have never gone above 4kW actual use. Actual need != summing all the nominal maximum rated loads of all appliances. In other words, it's not because your AC is rated 12kW, that you'd need 3 of these battery packs just for the AC. You might need 2, or maybe 3, I'm not saying that 2 (or 4) kW is enough always, everywhere for everybody - but there is no 'normal' (middle to upper middle class) home anywhere that would _need_ 5 or 10 of these units, as is suggested at various places in this thread.

<comment><USER60> To be honest, I don't know. It has 12kw on the outside. It's a DC inverter ducted system. I had to get the wiring to the house upgraded with 3 phase when it was put in. It doesn't use 3 phase but one of the phases is dedicated to the aircon. My electricity bill in summer is 20% higher.

</comment></comment></comment></comment></comment></comment><comment><USER61> Wow

This thing could sell like crazy in places like India. 10 kwH is enough to power an Indian home for more than a day and at 3500 dollars most middle class people would consider buying it seeing how frequent power cuts here are.

<comment><USER62> Really? According to wiki, India's middle-class makes anywhere from $10 to $50 per day. When you factor in that this will cost a lot more than $3500, would these really sell like crazy?

<comment><USER63> They can afford scooters, which cost one quarter that much. On $50 a day, it could be saved for in less than a year even if it costs $5000. Relative to their income, Indians have a lot of savings, due to their high savings rate (30%+). India's accumulated household wealth per adult is $5500. If you have two pairs of parents and one pair of grand-parents in one house, that is 6 * $5500 = $33000. Could be worth it, IMO it depends what is the lifetime of one such installation.

EDIT: Thanks for the correction on scooter pricing.

<comment><USER64> You'll find about 50 million people in middle class in India, who'll earn about $1k a month. Once you buy it, ship it, install it etc, I think $5k is a pretty typical cost figure.

That's quite steep. It's nearly 50% of your income. Also consider that as a rule, generally, the less affluent you are, the smaller percentage of income will be 'disposable' income. i.e. if you make $100k, you might have $60k in essential expenses, the remaining 40% of your income can be spent on savings or non-essential consumption like holidays. But if you make $5k like an average person in India might, you'll be hard pressed to not spend the vast majority on essential spending. So an investment that's 50% of a 1-year income may sound reasonable, but not when 95% of your income normally goes to essential expenses. That'd mean that you'd have to forgo 10 years of your entire disposable income to finance this.

Now how essential is it? I've traveled both in Africa and Asia and am familiar with powercuts (hell, I'd get em monthly in Montreal, too!) Generally though, it's not something I'd spend a lot of money on to fix. Cooking and heating is still gas powered. Essential lighting tops out at 100W, no need for a $3.5k battery that can deliver 20x that power. My smartphone/laptop are battery powered.

I mean, don't get me wrong, power cuts suck and nobody likes them. And for businesses (different story) they can be a disaster. (e.g. check out the World Bank 'Doing Business' reports [0], they look at power cuts affecting industry. It's a big factor)

But for homes? Most people cope just fine. You lose your TV and maybe your wifi if you don't have mobile internet, the rest can be managed.

Anyway India is obviously going to become a huge market, but that's a pretty long-term thing. You have hundreds of millions of middle class consumers in OECD countries who have the purchasing power and different motivations (environmental), backed by governments that are shifting to pro-solar, and huge profits-first industries that are seeing solar drop to super competitive prices within the next 10-20 years. India probably won't be a huge market in comparison. China perhaps, they're bigger, have more solar capacity and more purchasing power.

As for the scooter, you can buy 5-6 of them for the price of installing one of these, new, let alone second hand. And they're an essential part of transportation for which having nothing, or public transport is often not a viable alternative.

[0] [http://www.doingbusiness.org/reports](http://www.doingbusiness.org/reports)

<comment><USER63> True, and also it would have to compete with a typical generator using petrol.

</comment></comment></comment></comment></comment><comment><USER65> I'm going to install a 9kW solar grid on my roof in the next couple of months - capital cost is ~$40K USD. Without the Power Wall, I'd be selling power back to the utility at around $0.10 / kWh, and buying it back at $0.09 / kWh in the evenings. The Power Wall will also let me endure grid outages as well (you can't run your house on your solar panels directly).

I'm really curious about what the end-user cost is going to be for one of these batteries, after distributor markup and utility company rebates. Would be interesting to see if it pays for itself over the 10 year lifespan of the batteries.

I just reserved one.

<comment><USER66> $40K for 9kW solar sounds really expensive, I advice you to shop a bit or consider Solar lease. I have a 10 kW plant from SolarCity installed in late 2013. It is a prepaid 20 year lease, meaning I own the electricity and they own the panels, and the total cost (including installation, pv, inverters) to me is about 10K.

You seem to be getting a 1 cent more for the electricity, so your only motivation for this must be to have a back-up. But the 7kW powerwall is daily cycle, it may be a OK backup but not beyond a day or two.

<comment><USER65> Where I live (WA state USA), there are some crazy tax incentives here for solar. Rough math:

1\. 30% rebate on federal income tax, so that's $12K back in the first year. 2\. $0.54 / kWh WA state energy production credit which is capped at $5K / year. The estimated power production of a 9kW array over 1 year should get me pretty close to $5K back. The production credit expires in June 2020, which means that best case I get $25000 back from the state.

Without factoring in energy cost savings, I nearly break even in 5 years. Energy cost savings are somewhere in the neighborhood of $1200 / year with solar.

If the only rationale was energy savings, it's not a good investment. However, the tax incentives make it very attractive indeed.

More details on WA state incentives here: [http://www.solarpowerrocks.com/washington/](http://www.solarpowerrocks.com/washington/)

<comment><USER66> That is some killer state energy production credits. Now your plan makes complete sense.

</comment></comment></comment></comment><comment><USER67> Today is a big deal.

Open sourcing the patents to build fully solar-powered electrical grids around the will be a paradigm shift in the power structures of the world. I expect from today onward there will be a full-scale attack from those who stand to lose because of the reduced dependency on oil.

First they ignore you.

Then they laugh at you.

Then they fight you. <\--- WE ARE HERE

Then you win.

<comment><USER68> > I expect from today onward there will be a full-scale attack from those who > stand to lose because of the reduced dependency on oil.

Maybe. But remember we don't have the technology yet to completely move away from fossil fuels. The biggest issue I know of is making Airplanes electric which so far has not proven really feasible (as far as I can find anyway). This solves a huge chunk of issues but there are still plenty more before we can claim we have the technology to completely transition.

I'm excited for the possibility however.

<comment><USER67> Well, not jets, but propeller craft might be within reach:

[http://www.electronicsweekly.com/news/design/power/siemens-e...](http://www.electronicsweekly.com/news/design/power/siemens- electric-airplane-motor-2015-04/)

<comment><USER68> While it's a long way off that's pretty neat! Thanks!

</comment></comment></comment></comment><comment><USER69> A quick analysis of our local (St Louis) rates for an average (1700 sq ft) suburban house indicate that time shifting to get peak rate savings isn't worth it:

Payback time on the 10kWh battery would be around 26 years, and on the 7kWh battery would be 33 years.

So, at least in the midwest, I think you'd have to be either using a _ton_ of peak energy or coupling the battery pack with solar to make the investment worth it.

<comment><USER70> Isn't that the idea though? Solar + battery + electric car = no gasoline, electricity, or natural gas bill.

If the average car gasoline bill is $3000/year, electricity is $1000/year, and we demand a 5-year payback, we can spend at most $20,000 on a solar+battery+car system over what we would spend on a conventional gasoline- car and grid-house.

<comment><USER69> Yeah, that's the primary use, but there has been speculation here and elsewhere that a battery could be worthwhile just for exploiting the difference between peak and off-peak rates. This indicates that, at least for my area and usage, the answer is no, it's not worth it.

</comment></comment></comment><comment><USER71> The maximum temperature will be an issue here in Australia. In a typical place where it will be mounted, i.e. the garage, the temperatures will readily get over 40, close to 50 during summer.

I could see this also being a problem in places like Nevada and Arizona in the USA.

<comment><USER72> If your garage is getting to 50°C you've got a major insulation problem! Where are you located?

In both cases if min and max operating temperature are an issue it may be best to install in an FIP enclosure and use ducting to keep the enclosure and an optimal temperature.

<comment><USER73> In many houses, the garage is outside of the insulation; the garage itself has very little insulation between itself and the outdoors, and there's lots of insulation between the garage and the "habitable" parts of the house.

</comment></comment></comment><comment><USER74> Proof, if anyone still needs it, that Tesla is a battery company that builds cars, not a car company that builds batteries.

<comment><USER75> How big is their battery business compared to their car business?

<comment><USER52> Very shortly, its going to be as big as the entire world's lithium cell consumption currently.

</comment></comment></comment><comment><USER43> So why not solar power (1kW), storage (3.6kWh) with 25+ year life, inverter (2.8kW) and other electrical systems for just USD$8,702.

The batteries are only USD$2,910 of that.

[http://ironedison.com/edison-power-plus-system](http://ironedison.com/edison- power-plus-system)

<comment><USER76> What if one has already dozens of photovoltaic solar panels, and just need a good energy storage solution that lasts many years? I trust Tesla more than some others companies that they can deliver it.

<comment><USER43> You shouldn't. Tesla have a much shorter track record than someone like Iron Edison.

Also… if you read my comment, you'll see the batteries are cheaper than Tesla's… and if you look online, you can see they come in various configurations… rather than predefined 10kWh bricks with 2kW output.

<comment><USER77> History repeats itself :) Prepare for the 2nd round of Edison vs. Tesla!

</comment></comment></comment></comment><comment><USER49> I must say Elon is a brilliant engineer but not the best of orators.

<comment><USER78> I was thinking the same as I watched it. I was wondering if there were some technical issues to explain the slow start of his speaking part and if he might have been frazzled from whatever happened behind the scenes.

<comment><USER79> He was the same at the Dragon 2 launch. I get the impression that he doesn't rehearse for these events much, probably because he's probably got much more important things to work on.

</comment></comment></comment><comment><USER80> This is very clever! They're trying to increase demand for batteries independent of sales of vehicles, thus driving the economics of battery cost down and driving their vehicle prices down as a result. Get more batteries out there in different forms and use that demand to make the rest of their portfolio more affordable. Very rational strategy! Let's see what demand is like for their battery products.

<comment><USER81> Also given they just built the world's largest battery factories, it makes sense to sell some more batteries.

</comment></comment><comment><USER82> > 7kWh or 10kWh

Can anyone speak to what that could power? Could I run a load of laundry with it? How about dry it afterwards? Here in Italy people mostly take advantage of "solar power" by hanging clothes to dry, but just to get an idea of what the battery could run.

<comment><USER83> To put it in perspective: in Florida, in the summer, using a 4ton very old/inefficient AC in a 2000sqft house in 100 degree summer weather, electric oven, refrigerator, washer/dryer and all other household stuff. I would burn about 3kw / hr in the middle of the day. So in theory the 10kwh would power a extreme case like this for ~3hours, and 9 of them could do it for ~27hrs. So yes you could do everything you would normally do with household electricity with this.

<comment><USER84> Interesting numbers if you contrast them to another comment on this article saying his A/C was 12kWH.

<comment><USER83> I'm not aware of any consumer level ACs that draw that kind of juice. Given 10¢/kwhr (for easy math) that would still cost $1.20/hr or ~$8xx in electricity per month just for the AC.

</comment></comment></comment></comment><comment><USER85> I hope they have taken the safety technology from their Tesla vehicles and put it into their Tesla Energy batteries, because the thought of a 10Kwh lithium- ion battery exploding in my garage does not sound like the kind of mess I would want to be cleaning up. I couldn't see it mentioned anywhere, but presumably these batteries will be available in Australia for the same price? We always get charged more. If I can get one for $3500 AUD, count me in!

<comment><USER38> They certainly won't be $3,500 AUD.

3,500.00 USD = 4,447.86 AUD according to xe.com right now...

That, and the factory is in the USA. I would assume shipping something that large and heavy would add to the cost in Australia.

<comment><USER86> > That, and the factory is in the USA. I would assume shipping something that > large and heavy would add to the cost in Australia.

Put it on a boat. Shouldn't cost more than shipping inside the US.

<comment><USER38> You still need to ship it inside the US to the boat dock, and then pay to put it on a boat, and then pay to ship it from the australian dock to the homeowner.

<comment><USER87> Freight costs are so cheap they're essentially negligible. There's a reason why it's cost-effective to make stuff in China, and ship it all the way across the Pacific to the US, instead of just making them in the US.

<comment><USER38> It's still $1,000 AUD above what OP was hoping for even at free shipping costs.

</comment></comment></comment></comment></comment></comment><comment><USER88> The main advantage of Lithium Ion is the high energy density which is good for reducing the weight of laptops and electric cars but doesn't seem that useful in a house, especially when you compare it with cheaper and longer lasting battery technologies.

This feels more like them trying to find a new business line for their existing technology than coming up with the perfect technology for the home market.

<comment><USER57> There's been some talk about end-of-life electric car batteries getting recycled into these kind of devices, they may be priming that market too.

</comment></comment><comment><USER89> You should be able to put this thing on the top of your Tesla (it even looks like a roof box) to double your range!

<comment><USER90> Tesla car batteries are between 60kwh and 85kwh. These packs are 7kwh or 10kwh. Not going to get you that much farther with only a 10-15% increase in capacity...

</comment></comment><comment><USER91> To those who say that this battery doesn't do anything new and lead acid is cheaper, I would like to refer you to this article.

[http://www.thebestpageintheuniverse.net/c.cgi?u=iphone](http://www.thebestpageintheuniverse.net/c.cgi?u=iphone)

</comment><comment><USER92> How hacker friendly is this?

I'm not crazy enough to do anything fancy. But I would like to build some metric system to see the data and usages. If I can some how hack it so that it keep track of which devices uses the Tesla battery the most.

<comment><USER93> I highly doubt that will be possible. Actually I think it is entirely impossible, but I'm trying to future-proof my statement :-)

The battery system will just know how much power is currently being used. It will have no way to identify which devices are currently drawing power. For that, you'd need something like this on each outlet: [http://www.amazon.com/P3-P4400-Electricity-Usage- Monitor/dp/...](http://www.amazon.com/P3-P4400-Electricity-Usage- Monitor/dp/B00009MDBU)

Maybe future smart homes will have the Kill A Watt built-in to electrical outlets for monitoring purposes.

I imagine you will be able to get metrics on current usage, peak usage periods et cetera.

<comment><USER94> It may be possible to use non-intrusive load monitoring to determine the devices. However, I'm not aware of any products on the market using this tech.

[http://en.m.wikipedia.org/wiki/Nonintrusive_load_monitoring](http://en.m.wikipedia.org/wiki/Nonintrusive_load_monitoring)

</comment></comment></comment><comment><USER95> I live in a condo in Toronto, and peak hour electricity is more than double non-peak. How do I install this and have it charge during off hours and use the battery during peak?

</comment><comment><USER96> Germany has implemented so much solar they can overload the EU grid.

Batteries are the next thing for them. Many of the comments here aimed at the States make sense. Use cases aren't as broad here for many reasons.

But, who says these have to be sold here?

Great move, IMHO. Storage is a growing concern. Most all of the renewables suffer from variances in production.

Elon is likely thinking globally. Just get storage production moving and boot strapped into self-sufficiency. Doesn't matter who buys it, just that they do.

Costs drop, scale improves on things, and he's positioned to take advantage of materials science as it yields better / more diverse options. Think of those aluminum batteries just announced at Stanford. The energy density is lower, but they charge very quickly.

If those prove viable, they can be added to the Tesla catalog, and if their life time is high enough, might just be perfect for augmenting things like solar and wind.

</comment><comment><USER97> Any news on international orders? I live in Australia, and would love to integrate this as a full off-grid solution.

</comment><comment><USER98> I wonder how many years this battery will last before requiring replacing?

Storing power over the course of the day is an intriguing idea, because the house is generally empty then. Instead of selling back to the power companies, I would rather have it power this battery so that my night time use is "free".

</comment><comment><USER99> See an analysis of whether this makes sense for home, business, and utilities: [http://www.purewatercraft.com/thinking-about-energy- storage-...](http://www.purewatercraft.com/thinking-about-energy-storage- using-lithium-ion-batteries/)

</comment><comment><USER100> For those interested in investing and finance, I have a question.

Why would this news not cause Tesla's share price to go up?

It seems generally well-received (well, as much of an indicator as 812 points on HN is). Surely that's a good sign? Or did the announcement not live up to the hype, causing people to dump stock?

<comment><USER101> Tesla stock price has been gradually increasing the last week or so in anticipation of the event, so the event has already been "priced in." Further, the FOMC (fed) recently scared the market, because interest rates may be rising some time in the future (September? December? who knows), causing people to switch from investing in equities (stocks) into treasury bills. In short, this information was already anticipated but it also had to fight the FOMC announcement.

<comment><USER100> Thanks. Makes sense.

</comment></comment></comment><comment><USER102> I know they pitched this for solar, but I bet that won't be the most common use, at least initially.

My power company (XCel, if it matters) keeps trying to install a "Saver Switch" in everyone's house to shut down their A/C when demand is high. Basically they want to load shed your air conditioner, and they're willing to pay you for the privilege.

This is a lot more expensive, but it's also a hell of a lot more versatile. How much would it be worth for them to subsidize installing these with a switch that would let the utility remotely toggle you off the grid at their discretion? Plus it would actually save consumers money in any market with tiered electric rates. Plus it would help them deal with the intermittency of solar power.

</comment><comment><USER103> _Massive_ news for doomsday preppers everywhere...

</comment><comment><USER104> Great, except that all these nice batteries are produced with extremely toxic processes, involve heavy metals, and consume a whole bunch of fossil fuel during their production. Hardly a good case for the environment when you factor everything together.

<comment><USER105> Lithium-Ion batteries aren't all sweetness and light, but it's not a particularly dirty process compared to Ni-Cd, and certainly you have to factor in benefits of reduced generation.

<comment><USER50> Ni-Cd batteries are so bad for the environment that the EU is forcing companies to phase out their use. Saying that Lithium Ion batteries are better than something that's been banned for most purposes because it's so toxic is not exactly high praise.

</comment></comment></comment><comment><USER76> I would like to buy one. Can we use it in Western Europe? Will it be certified for the EU power grid network? How long will the battery last (expected battery life)? About 7-8 years would be the minimum, but is that the lifespan of lithium batteries?

</comment><comment><USER106> I might spend $480 on electricity per year. I can't see this thing having an ROI within its lifespan. I also don't have solar panels, and have a very reliable power grid. Any reason I should consider buying one?

<comment><USER107> We spend over $2,000 per year and it's just me and my girlfriend. From the sounds of it you have either very good rates or perhaps a frugal lifestyle? Either way it's impressive.

<comment><USER108> I think it depends on local weather. We spend about $600 on electricity and $600 is gas per year for 4 people in the Bay Area. And this is with an older water heater and furnace in an old house with moderate insulation. We would replace the heater, furnace and improve the insulation before even considering solar ourselves.

<comment><USER55> +1 to first upgrading your home. I live in the Bay Area but in a tightly sealed late 90's 1600 sqft house. No A/C. Recently upgraded our furnace and water heater to high efficiency models, and now spend about $400/year electricity, $400/yr for gas. Even accounting for the warmer winter this year, the gas savings was about 14%. There are pretty good incentives in the Bay Area for home energy upgrades if you do multiple at once: [https://www.bayareaenergyupgrade.org/program- overview](https://www.bayareaenergyupgrade.org/program-overview)

</comment></comment></comment></comment><comment><USER109> While I think this announcement is great news, there are at least two caveats to keep in mind that can mine the long term value proposition:

\- If there are many users, the peak/non-peak price differences (arbitrage) will disappear. This is because of supply/demand law.

\- If solar energy/battery storage takes off, it will be heavily taxed. There is an impending "Sun tax" being implemented in Spain, that aims to make more expensive running a home solar source than taking power from the grid. If necessary, they will tax Lithium.

So the Tesla value proposition is in all cases short term.

<comment><USER110> Your analysis of the arbitrage is faulty - if there's a cost associated with time-shifting energy, then the gap will only narrow to the extent that it's still economically justifiable for people to invest the money in time-shifting energy. What you're describing (no peak/non-peak difference plus people still buying batteries to time-shift energy) isn't a steady state - why would people continue to buy the batteries when they're going to lose money on the deal? You'd actually expect the gap to be the price difference per watt plus some additional amount for the capital and inconvenience.

Also, if there's significant arbitrage, it will also reduce peak prices - because of reduced demand, and also because of reduced costs of expensive additional capacity. I.e. it can reduce energy costs for people who _don 't_ use it.

<comment><USER109> Yes, what I meant is that each Tesla battery sold will contribute to reduce the peak price and to increase the non-peak price, effectively reducing the gap that is the basis for the value proposition.

Because of this effect, the value proposition for existing Tesla battery owners will lower over time. Ironically, the ones that benefit at long term are the non-owners because their peak time price will be lower.

</comment></comment></comment><comment><USER111> I wonder if Elon and the owner of SolarCity will get in touch. Oh wait... ;)

</comment><comment><USER78> I actually really wanted him to put his "blue square" in context. Would have been interesting compared to land area dedicated to rooftops, parking lots or something.

</comment><comment><USER112> How well do you think these would work in RVs when paired with the number of solar panels that fit on top of an RV? Would this work well at burning man vs running a generator?

<comment><USER113> You'd have to calculate it and your expected power usage. You probably wouldn't be able to run AC on full all day without a massive solar array. Check out how big a 100w solar array is, how many of those can fit on your RV roof, and how much power your AC uses. You'd also need a big (and not 100% efficient) inverter. Also take heat and dust inefficiencies into account.

TL;DR you're better off going in on that industrial diesel 3-phase generator rental which comes on its own trailer.

</comment></comment><comment><USER64> I felt the 'area needed in the US' to be a bit disingenuous. I very much recommend David Mackay's Without the Hot Air, a great talk he did at Harvard on area required can be found here:

[https://www.youtube.com/watch?v=GFosQtEqzSE](https://www.youtube.com/watch?v=GFosQtEqzSE)

Beyond that, very glad to see this happen. It's one of the factors necessary to push a sustainable electrified future forward.

</comment><comment><USER114> I suppose this must be better than storage heaters. Not sure how big these are outside the UK, but basically they use off-peak electricity to heat bricks that then slowly release the heat the next day. We had them when we were a kid and they were rubbish.

[http://en.wikipedia.org/wiki/Storage_heater](http://en.wikipedia.org/wiki/Storage_heater)

</comment><comment><USER115> Is there anyway to model the energy saving costs of these in like a small town?

I mean if power stations only had to produce N/kW/h at a constant rate to power every home in the region then would there be any energy savings? Instead of the typical, scale back at night, boost up during the day system?

If we could calculate the energy usage of every home down to the Watt then surely there wouldn't be any waste?

</comment><comment><USER116> I'm curious if local governments will give subsidies to aid in distribution of such devices - many places have issues with the power grid.

</comment><comment><USER117> If everyone had these and they were all attempting to "charge during nonpeak hours" wouldn't those hours become the peak hours?

<comment><USER118> If enough people had these in their homes then there would no longer be "peak hours" or "non-peak hours", I would think that this would normalize the grid so that pricing is always fairly consistent.

<comment><USER119> Which is more or less the point, of course. If you can even out the peaks and troughs then you can make all this stuff much more efficient.

Of course, that assumes that generation can be consistent. Right now, that is the case. If we took the existing grid and just gave everybody batteries, we could make power consumption flat throughout the day, which would greatly reduce costs. That would be cool!

The idea is that in the future, solar dominates. There you inherently have peak and non-peak hours, because you generate more electricity at noon than at midnight. This is completely impractical if you go straight from generation to use, because the times don't match up. But throw in storage to flatten it all out, and it works.

</comment></comment></comment><comment><USER120> Implementation of such technologies is exactly what I worked on in grad school, and now I'm happy that a company like Tesla is actually gonna bring it to the masses. Batteries are essentially the "killer app" for the power-grid, and will accelerate the adoption of renewables with stochastic power outputs such as solar and wind. Thank you Tesla!

</comment><comment><USER121> The max temperature basically makes it a no-go in much of the so-called "sun belt" where solar power conditions are optimal.

<comment><USER122> In those areas I guess you just install it inside the home somewhere, which is the whole point of making it look decent.

</comment></comment><comment><USER123> This would all make more sense if they made solar panels to go with the powerpack. Otherwise, it's just a huge battery.

<comment><USER124> SolarCity is another startup that Elon chairs... The idea is that the batteries and the energy generation process/supplier don't have to be the same.

</comment></comment><comment><USER125> I think this is a move that will break the focus rule for a startup. Batteries _and_ cars. There is room for only one.

<comment><USER126> Wright brothers: focus on wings or controls or engines! you only have room for one!

Apple: focus on hardware or software! Macs or iPods. You only have room for one.

Edison: focus on lights or electricity! You only have room for one.

Uber: focus on the driver network or the app! You only have room for one.

It's not a hard and fast rule. The point of focus is to get you to prioritize what important, but something you need to do multiple things.

<comment><USER125> The problem with all of your examples is they still only sell one thing. Tesla now sells 2 things. That means sales, marketing team, strategy, support, for 2 things. Like, having 2 companies.

<comment><USER126> Another example, Standard Oil: don't just sell the oil. Refine it, and sell the kerosene, and the lamps, and also sell the gasoline, and when you're left with paraffins invent paraffin candles and sell those too...

<comment><USER127> Ha! The aboriginal Americans have nothing on Standard Oil. They just used every part of the buffalo. Standard Oil invented uses for every part of the oil.

</comment></comment></comment></comment></comment><comment><USER128> With the hoped roll out of more electric cars charging them will place an undue load on the grid, if it isn't orchestrated. Tesla plan to be able to control when they discharge to the grid, so this could go some way to reduce stresses on the electric grid when more people want to recharge it. Just a thought.

</comment><comment><USER49> $3500. Nice!!!

<comment><USER129> I'm intrigued at the backup possibilities, because we live in a forested area of the northeast where outages are common during storms. But at 3Kw a single unit isn't large enough to power our entire home, and I didn't see a figure for how long it can operate at peak load. If I need two then we're getting closer to the cost of a natural gas fired generator. This analysis, of course, is completely ignoring the environmental benefits.

<comment><USER130> can we just try living without electricity for 2 days? millions of humans did it for hundreds of years prior to us and they managed just fine

<comment><USER129> During hurricane Sandy our family was without power for 12 days. What's the longest you've gone?

</comment></comment></comment></comment><comment><USER131> The AWS roll-out also seems like big news. Last I checked, data centers accounted for 2-3% of domestic energy spend, and they typically feature backup batteries and generators. Tesla may have entered the (enormous) data center market the moment it broke ground in Nevada.

</comment><comment><USER132> Tesla vs Edison, Round 2.

Interesting twist that this time around, Tesla is pushing for DC, while Edison is behind AC.

</comment><comment><USER133> I believe the Chinese innovator BYD has a portfolio of similar products already. BYD got some press play in the West when Warren Buffet invested in them. They are making a slow patient push in the U.S with electric buses after flopping with electric cars.

</comment><comment><USER134> A German company is doing this too. Nice to know it's more like an industrial movement not just one company doing it. There is hope.

[http://www.asd-sunstorage.com/](http://www.asd-sunstorage.com/)

</comment><comment><USER135> Here's the link to live stream: [http://www.teslamotors.com/livestream](http://www.teslamotors.com/livestream)

One interesting thing to note is the collaboration with Amazon...

</comment><comment><USER136> > The world currently consumes 20 trillion kWh of energy annually.

> Enough energy to power a single family home for 1.8 billion years or supply > energy to a nuclear power plant for 2,300 years.

That's, ..., not the way I would have written it.

</comment><comment><USER137> The map graphic at the beginning was pretty powerful (please excuse pun)

</comment><comment><USER138> You can buy a used Mitsubishi i-MIEV (early electric car with very short range) for less than $8,000.

So, do that. Then strap one of these Tesla home batteries on it.

Bam!

(NB some experience with heavy-duty DC electricity required.)

</comment><comment><USER139> I can't wait to see the first users proudly cutting their connection to the power grid, claiming they are now energy independent and free from oppressive utility companies...

</comment><comment><USER140> It would be cool if Tesla could also come up with something to improve batteries used in portable devices, so we can use phones or laptops more than 1-2 days without recharging.

</comment><comment><USER141> How sustainable is putting a large lithium battery in every home?

</comment><comment><USER142> I doubt they would install one in an RV... but I can dream.

<comment><USER143> Likewise for boats. It's high time we stop using lead batteries in vehicles where weight matters, and the pricing on this looks _great_.

<comment><USER144> I thought about boats as well.

Do you know the weight and dimensions of this?

It looks like it is equivalent to 835 Ah @ 12V. That is 10 lead batteries. You probably can buy more than 3 lead batteries for 300 dollars, but the weight and 10 year warranty does look attractive.

<comment><USER142> Those would be crap lead acid batteries at $100.

I have 500 Ah in 4 AGM batteries that cost me $1200. If all that 835 is usable I'd have to spend $3600 to come close with the same AGM's I'm using now.

</comment></comment></comment></comment><comment><USER30> _Enough energy to power a single family home for 1.8 billion years or supply energy_ to _a nuclear power plant for 2,300 years_

I think I see the problem...

</comment><comment><USER145> Do these green numbers take into consideration the energy expended on producing the Li-ion batteries? Surely that must be a messy mining operation.

</comment><comment><USER146> Can someone please share what a single family home can do with 10kWh?

If I pay for this do I have to plug this thing into my own electrical grid to keep charging it?

<comment><USER147> According to [http://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3](http://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3) the average U.S. home uses 10,908 kWh/year, so this would be enough to keep the home running at full load for about 8.4 hours. Not bad.

If you took steps to reduce consumption (avoiding using heavy demand appliances like electric ovens, etc.) it would last a lot longer. With a little care, you could probably run for a couple of days on one of these, particularly if you had LED lights, etc.

<comment><USER148> Due to the fairly low peak power draw the battery supports (3 kW) you would have to avoid using those heavy appliances anyway, especially simultaneously.

</comment></comment></comment><comment><USER149> I predict Venezuela will be the biggest importer of powerwalls to cope with daily outages.

Who knew oil-rich but impoverished countries would help fuel innovation.

<comment><USER150> Venezuela has almost no dollars. They don't have the money to import toilet paper much less multi-thousand-dollar battery installations.

<comment><USER149> Venezuela has plenty of money from oil which goes to the hands of the power elites and their cronies and families.

So yes, while 29 million people lives in total poverty, there is one million families that would benefit a lot from that invention, and they will get it, believe me.

</comment></comment></comment><comment><USER151> Do we know the prices they're charging for the utility versions? Does it make it a viable option for a lot of utilities?

</comment><comment><USER151> I'm amazed at the price. This actually makes it competitive with whole house generators at least for backup electricity.

</comment><comment><USER152> As the picture shows, can this evolve into a battery station residing within the garage? Experts please share your opinion.

</comment><comment><USER153> Pretty decent pricing, good enough for developing nations with power cuts where people currently use diesel generators.

</comment><comment><USER154> Well done Tesla. Next project? I have an idea. How about standardizing battery packs for robots.

</comment><comment><USER155> Forget the USA.

Imagine what these decreased battery prices are going to do for solar power in LEDCs.

</comment><comment><USER156> How is lithium mined and disposed of? Is that much of an issue?

</comment><comment><USER157> Feels like we're finally living in the future.

</comment><comment><USER158> I thought Panasonic made batteries for Tesla?

<comment><USER159> With _

</comment></comment><comment><USER160> it sounds so awesome, are there any reasons why I _shouldn 't_ get this?

</comment><comment><USER161> 2 billion battery packs, and how many solar panels to feed them ? Did I miss the number ?

<comment><USER162> A lot of the stuff Tesla is saying about this is quite weird. (In the press kit and in Musk's live stream.) For example, the _first sentence_ of the press kit:

> The world currently consumes 20 trillion kWh of energy annually. Enough > energy to [...] supply energy to a nuclear power plant for 2,300 years.

Am I missing something, or is that an entirely bizarre comparison to make? What does this even mean?

<comment><USER68> > Batteries are not a source of energy. They store energy. (You'd be surprised > at how many people don't grasp that.) Talking about how many batteries we > need to power the world without talking about where that energy is coming > from is silly.

I'm not sure why you got such a weird impression. In his talk he clearly states that the power would be coming from solar energy. He even explained how much space you'd need for solar arrays and batteries if you want to provide the entire United States with power day and night (the biggest need for batteries).

He also mentioned there is utility for the battery to be used with your powergrid but the big win is using it with solar energy.

</comment></comment></comment><comment><USER163> My tweet from a few days ago:

It would be poignant if Tesla (the company) decentralized power generation & storage considering free energy was Tesla's (the man) dream

<comment><USER164> Everyone has known what this announcement was going to be for a month.

<comment><USER163> I wasn't implying that I predicted the future. I'm commenting on how this brings their product mission more in line with their company name.

</comment></comment></comment><comment><USER165> Hey, for fun let's use this to do a rough math check on Tesla's future plans.

The battery is $3500 for 10kWh.

Model S with a 270kWh battery is advertised with a range of 240mi.

Model 3 aims for a minimum range of 200mi, or 5/6, a.k.a. 225kWh battery.

225 is 22.5 * 10.

22.5 * $3500 = $78,750.

Model 3 is supposed to be $35,000.

I believe in Elon Musk completely and I want nothing more than to see him succeed and I have been blown away by what Tesla Motors and SpaceX accomplish at every turn.

But even so, I will be amazed again if the Gigafactory can truly make the price point feasible. I really believe they'll do it, I just don't see how.

Can the factory's massive gains in efficiency really change things by such a huge factor in 2 years? (Model 3 targets 2017, doubtful.)

<comment><USER166> Your battery sizes for the cars is way off. The Model S has come with a 60 (no longer available), 70 and 85 kWh battery. The 240 mile vehicle is the newer 70 kWh battery.

70 is 7 * 10. 7 * $3500 = $24,500.

<comment><USER165> Yeah I have no idea how I managed to add 200kWh in there. Thanks for pointing that out. Wow.</comment></comment></comment>


Why India's best tech schools produce more entrepreneurs than the Ivy League - <AUTHOR> http://qz.com/262730/why-iits-produce-more-entrepreneurs-than-ivy-league-institutions-like-harvard-or-yale/

<comment><USER2> You need Cash/Caste to succeed as Entrepreneur in India. [http://www.nytimes.com/2013/06/16/opinion/sunday/caste-is- no...](http://www.nytimes.com/2013/06/16/opinion/sunday/caste-is-not- past.html) and

</comment><comment><USER3> It's not really impressive that IIT (16 schools) managed to turn out slightly more entrepreneurs than Harvard (1 school).</comment>


Steve Jobs' Hi-Fi System - <AUTHOR> http://blogs.kcrw.com/rhythmplanet/steve-jobs-hi-fi-system/

<comment><USER2> "To my surprise, he never owned a tube amp and preamp—both of which allow for a smoother, more organic sound." I put my tube amp in a tray of tofu for an even more organic sound.</comment>


Why I don't like the term "AI" - <AUTHOR> http://lambdamaphone.blogspot.com/2016/12/why-i-dont-like-term-ai.html <comment><USER2> it would be nice if natural talents didnt exist and life was more like World of War Craft, where everyone starts with a blank slate and skills are only earned by effort and hardwork. Thats not how it is though, so whenever I hear a term like 'ableism' it makes me cringe. I will never be as fast as Usain Bolt. Sometimes it doesnt make sense to pretend the playing field is level just so nobody gets tgeir feelings uurt.</comment>


Cellphone Thefts Grow, but the Industry Looks the Other Way - <AUTHOR> http://www.nytimes.com/2013/05/02/technology/cellphone-thefts-grow-but-the-industry-looks-the-other-way.html?hp&pagewanted=all

<comment><USER2> Interesting point. Are we wanting the phone (i.e. the manufacturer) to brick the device when it's been perceived as stolen? I had always thought of cellphones like bikes and assumed that there'd always be some inevitable amount of theft, but the two devices aren't actually that similar.

<comment><USER3> I think there's enough of an incentive for hackers to figure out how to unbrick these phones that it wouldn't be much of a deterrent.

If the bricking were truly permanent, like blowing an efuse or something, the risk of false positives bricking phones that aren't really lost is probably higher than the phone makers are comfortable with.</comment></comment>


Ask YC: How does facebook round corners on users' pictures? - <AUTHOR>

My initial guess would be Jscript. Although it could also be done using a transparent image over the users picture <comment><USER2> They use the CSS Sprite technique to overlay a certain portion of this image <http://static.ak.fbcdn.net/images/ui/UIRoundedImage.png> on top of your picture. It's hard to see in the browser but above the blue rounded corner mask there is a white corner mask.

</comment><comment><USER3> As you can see, this question has been answered, but in the future you should consider using Firebug (<http://getfirebug.com/>). With firebug, you can inspect any element on a web page and see exactly how things are done. I've learned all sorts of tricks this way.

<comment><USER2> And if you're a Safari user, you can just right-click on something and choose "Inspect Element".

</comment></comment><comment><USER4> <http://static.ak.fbcdn.net/images/ui/UIRoundedImage.png>

They overlay that image on top.

</comment><comment><USER5> Here's a good tutorial on the technique: <http://cssglobe.com/post/3714/css- sprites-rounded-corners/>

</comment><comment><USER6> The question has been answered already but if you'd like to see it for yourself, you can right click on the image and hit "View Background Image".</comment>