<story><title>How the electricity markets respond to a nuclear trip</title><url>https://blog.gridstatus.io/ercot-nuclear-trip/</url></story><parent_chain><item><author>huijzer</author><text>An individual inverter can usually switch in about 4 ms. A Tesla Megapack can go from 0% output to max output in 100 ms. Conversely, gas turbines (the fastest type of traditional power plant) takes about a minute to go from say 40% to 60%. Even in the fastest possible design, there is a mechanical rotor (kinetic energy) that has to change speed.&lt;p&gt;What I mean to say is that solar and batteries are likely an order of magnitude faster to respond to sudden demand changes. So I would expect a more reliable system when more solar and especially batteries are being added.</text></item><item><author>toomuchtodo</author><text>Something interesting is that with substantial solar and batteries being deployed in the ERCOT market (in scope grid operator for this piece), solar generation in excess of what the grid can consume with load combined with grid forming inverters (vs traditional grid following) can step in when called upon if a traditionally firmer generator (coal or nuclear) trips out. The potential is already there (photons hitting panels), simply turned down to align with grid demand (curtailment), but if the sun is shining and PV is called upon, curtailment can quickly turn into emergency grid support as long as the sun is shining (I am not familiar how long it takes from ISO signal to inverter command).&lt;p&gt;It would be cool if individual generators shared this curtailment status&amp;#x2F;reserve in realtime publicly similar to how ERCOT reports real time generation mix data.&lt;p&gt;Citations:&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=40908526&quot;&gt;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=40908526&lt;/a&gt;&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=38848989&quot;&gt;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=38848989&lt;/a&gt;</text></item></parent_chain><comment><author>lmm</author><text>&amp;gt; Even in the fastest possible design, there is a mechanical rotor (kinetic energy) that has to change speed.&lt;p&gt;The point of ramping up the power plant is to make sure that the rotor &lt;i&gt;doesn&amp;#x27;t&lt;/i&gt; change speed (by e.g. burning more fuel to push it harder, because there&amp;#x27;s suddenly more load on it), and that can happen a lot faster than spinning up the rotor from scratch. Indeed a heavy rotor helps to stabilise the grid &amp;quot;for free&amp;quot; by acting as a flywheel (which, in a way, responds even quicker to the demand change than a battery can).</text></comment>
<story><title>How the electricity markets respond to a nuclear trip</title><url>https://blog.gridstatus.io/ercot-nuclear-trip/</url></story><parent_chain><item><author>huijzer</author><text>An individual inverter can usually switch in about 4 ms. A Tesla Megapack can go from 0% output to max output in 100 ms. Conversely, gas turbines (the fastest type of traditional power plant) takes about a minute to go from say 40% to 60%. Even in the fastest possible design, there is a mechanical rotor (kinetic energy) that has to change speed.&lt;p&gt;What I mean to say is that solar and batteries are likely an order of magnitude faster to respond to sudden demand changes. So I would expect a more reliable system when more solar and especially batteries are being added.</text></item><item><author>toomuchtodo</author><text>Something interesting is that with substantial solar and batteries being deployed in the ERCOT market (in scope grid operator for this piece), solar generation in excess of what the grid can consume with load combined with grid forming inverters (vs traditional grid following) can step in when called upon if a traditionally firmer generator (coal or nuclear) trips out. The potential is already there (photons hitting panels), simply turned down to align with grid demand (curtailment), but if the sun is shining and PV is called upon, curtailment can quickly turn into emergency grid support as long as the sun is shining (I am not familiar how long it takes from ISO signal to inverter command).&lt;p&gt;It would be cool if individual generators shared this curtailment status&amp;#x2F;reserve in realtime publicly similar to how ERCOT reports real time generation mix data.&lt;p&gt;Citations:&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=40908526&quot;&gt;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=40908526&lt;/a&gt;&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=38848989&quot;&gt;https:&amp;#x2F;&amp;#x2F;news.ycombinator.com&amp;#x2F;item?id=38848989&lt;/a&gt;</text></item></parent_chain><comment><author>leymed</author><text>I think you’re missing the point how turbine-generator works. The rpm speed has to stay the same, meaning the rotor speed doesn’t change. As long as you don’t have closed circuit you’ll waste that mechanical energy. If you meant starting from stand still position, then you’re right it takes couple minutes to pick up the load.&lt;p&gt;With that said, turbines responding in couple minutes are more reliable as a baseline when you’re planning load flow of as big as country or wider area. The basic reason is that you have source of energy under your control such as nuclear, water, gas, coal. You cannot have solar, wind as your baseline, I don’t want sound dramatic, but it’s kind of suicidal to do that. Solar’s ramping is not a win when you consider greater scale.</text></comment>