I think the nodal pricing structure in the Texas grid is extremely conductive to an efficient electricity market.
It incentivises the grid-stabilizing deployment of batteries.
Texas is really the market to watch and learn from.
How the electricity markets respond to a nuclear trip
41–50 of 86 posts
Re: How the electricity markets respond to a nuclear trip
#42Earlier quoted context omitted.
How is 10 - 20 years "sustainable"?
We’re currently experiencing a Cambrian explosion in battery tech. As the technology matures, and we establish a closed loop ecosystem to build and then recycle these systems, longevity can improve over time. To get better at something, you must first suck at it, and 10-20 years is not an immaterial service life for an asset that just sits and hums with no moving parts.
I agree if we were talking about a motor or a pump, but it seems like batteries basically devastate the environment every time we make one, and doing that millions of times every ten years is probably not great. (But I don't know anything about that specific battery technology.. perhaps it's just saltwater and two dissimilar metals.)
Re: How the electricity markets respond to a nuclear trip
#43Earlier quoted context omitted.
Batteries are extremely expensive per megawatt, not very durable, require carefully controlled temperatures, and their manufacturer and recycling extract a tremendous cost from the environment. For non-mobile usage, batteries shouldn't be seen as any kind of viable solution at scale. However, there are other ways to store energy; unfortunately, most involve converting electricity to another form of energy such as pot…
> For non-mobile usage, batteries shouldn't be seen as any kind of viable solution at scale. Lithium-ion, sure, but aren't there a whole host of other battery chemistries that are basically too big / too heavy to put on vehicles but a lot cheaper so well suited for stationary storage? Are they all still at the research phase and so currently more expensive than the decades-of-learning-curve lithium-ion?
Lithium-ion is the cheapest form of stationary storage for the sub-8 hour duration niche. The vast majority of battery storage being deployed is lithium-ion.
Sodium-ion is the second largest contender, with a few pilot facilities opening in China recently, but it will be a few years before it eclipses lithium-ion.
Re: How the electricity markets respond to a nuclear trip
#44Earlier quoted context omitted.
It's a fair point (why curtailment is in effect), and I think speaks to the fact that more granular and timely data is needed wrt all nodes and transmission segment within the system. Also a call for more batteries everywhere between generation and load. With regards to transmission congestion, that is easily fixed with installing batteries at currently storageless renewable generation facilities (the batteries then…
Batteries are extremely expensive per megawatt, not very durable, require carefully controlled temperatures, and their manufacturer and recycling extract a tremendous cost from the environment. For non-mobile usage, batteries shouldn't be seen as any kind of viable solution at scale. However, there are other ways to store energy; unfortunately, most involve converting electricity to another form of energy such as pot…
They're the cheapest form of storage after recent price declines, even cheaper than pumped hydro and compressed air.
Re: How the electricity markets respond to a nuclear trip
#45Earlier quoted context omitted.
When there’s a load imbalance on the grid (more load than capacity), the turbines physically slow down as inertial energy is extracted from them. This causes the grid frequency to drop. It takes some time to ramp up production and speed up the turbine etc.
The maximum slow-down of the turbines (before the generator trips off-line, removing the load on it) is far less than you seem to assume. The article's graph shows the 60.00Hz grid frequency dropping...all the way to 59.92Hz. That's 0.1333%. For an on-line gas turbine, the time to ramp up production is the second or few needed for the automated controls to open the throttle on the "Gas IN" pipe. It's basically a natu…
The more interesting thing about rotating power plants is that they are routinely destroyed by transmission outages, because when a rotating generator is suddenly disconnected from its load, there are infinity terms in the equations that govern its motion and infinity isn't a thing you can resist. For steam turbines the control system has to slam the valve shut on the steam, otherwise the machine would overspeed, and closing that valve destroys some sacrificial part of the steam plumbing (hopefully). Steam power plants have to be inspected and repaired after disconnects and this is one of the numerous reasons why fission kinda sucks on the reliability front.
Re: How the electricity markets respond to a nuclear trip
#46Earlier quoted context omitted.
Most curtailment IIRC is due to insufficient transmission capacity. I doubt curtailed solar can be called upon in an emergency unless the emergency is located very close to the curtailed solar.
The transmission lines run to solar farms should be able to take 100% of the output of the farm and then some otherwise the farm was over built and wasted money.
That's not necessarily optimal. For home installs, you can overbuild panels because they're cheap compared to the inverter. Then you curtail sometimes at midday and have extra energy on cloudy days and in the morning/afternoon. Turns out that's more cost effective than sizing the panels perfectly. The same logic could apply to utility farms, because transmission lines can be expensive. I don't really know myself since I don't work in the industry, but I would not be surprised if they slightly overbuild vs. the transmission line capacity.
Re: How the electricity markets respond to a nuclear trip
#47Earlier quoted context omitted.
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. With that said, turbines responding in couple minutes are more reliable as a baseline when y…
Reliable until it isn’t. The entire grid is a statistical system where we define the acceptable uptime. Renewables are as good as any other energy source bringing its own fuel, just need to take the variability into account. https://www.nytimes.com/2022/11/15/business/nuclear-power-fr...
You’re correct that the system is statistical, and it’s planned accordingly. However, we cannot omit the fact that it’s the running turbine that responds faster to the unpredictable nature of the grid. The backbone of the grid, aka the baseline plants, are extremely responsive to unpredictable nature of the grid at a greater scale, with enough amount of safety margins to bring into service under unusual circumstances. I really don’t see, at least what we have in hand rn, that happening with solar or wind. Without strong baseline you’d experience supply demand imbalance, in engineering terms frequency decay, voltage collapse.
Re: How the electricity markets respond to a nuclear trip
#48Something 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…
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. What I mean to say is that solar and batteries are likely an order of ma…
> An individual inverter can usually switch in about 4 ms.
A quarter of a 60 hz cycle or a fifth of a 50 hz cycle is really fast. For comparison, it takes a current limiting fuse around a half cycle to clear a short circuit current and a GFCI takes around two cycles to clear a ground fault.
Re: How the electricity markets respond to a nuclear trip
#49Earlier quoted context omitted.
We’re currently experiencing a Cambrian explosion in battery tech. As the technology matures, and we establish a closed loop ecosystem to build and then recycle these systems, longevity can improve over time. To get better at something, you must first suck at it, and 10-20 years is not an immaterial service life for an asset that just sits and hums with no moving parts.
I agree if we were talking about a motor or a pump, but it seems like batteries basically devastate the environment every time we make one, and doing that millions of times every ten years is probably not great. (But I don't know anything about that specific battery technology.. perhaps it's just saltwater and two dissimilar metals.)
Re: How the electricity markets respond to a nuclear trip
#50Where does the 1500MW of heat the reactor is producing go, immediately after the generators are isolated from the grid?
I would assume the cooling loop is still running on generator and/or backup utility feed power, so the heat from the reactor would go into the water of the cooling loop, and then the heat would be rejected into the atmosphere when the cooling loop water evaporates in the cooling towers, with the leftover heat being discharged into the river/lake/cooling water source.