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My state proposed a grid battery solution that would have provided power for the entire state for up to 1-2 days IIRC. They didn’t approve it, but the budget wa
by ianai 3y ago
My state proposed a grid battery solution that would have provided power for the entire state for up to 1-2 days IIRC. They didn’t approve it, but the budget wasn’t astronomical. I honestly wonder if the worry about off hours use is a little overblown.
Infrastructure has a history of both being expensive up front and funded. Imagine if the US didn’t have highways and trying to explain all the impacts to the GDP that modern highways make. The price would almost seem trivial compared to the trillions per year of GDP that goes over asphalt.
- ftth_finland 3y agoWhere can I find more information about this? I can find very little information about long term storage, not that 1-2 days is much. Most seem to think 4 hours qualifies as storage.
- pydry 3y agoThis model thinks that 5 hours gets us to 97%: https://reneweconomy.com.au/a-near-100-per-cent-renewables-grid-is-well-within-reach-and-with-little-storage/ https://reneweconomy.com.au/a-near-100-per-cent-renewables-g... 5 hours is pretty doable with batteries and pumped storage. It's a lot and very expensive but not an impossible amount and there aren't any cheaper/quicker alternatives that I'm aware of. I think Australia will be almost half way to 5 hours already once Snowy 2 is finished. That's just one pumped storage plant & studies show that the geography to build more is plentiful. That last 3% can probably be eventually provided with via hydrogen, which, unlike the other two, is inefficient to roundtrip (~45%) but it lets you store large amounts of power for long durations easily.
- pfdietz 3y agoGlad to hear someone else beating the hydrogen (or some e-fuel) drum for that last few percent.
- 0cf8612b2e1e 3y agoI do not understand why there is not more focus on fuel synthesis. If electricity becomes “free” for hours a day, even crummy roundtrip efficiency seems like a great option to soak up extra capacity and get long term (seasonal?) storage.
- ftth_finland 3y agoCan you run fuel synthesis profitably purely on intermittent renewable power and scale up and down in real-time? Capital costs are high and utilization will be low.
- pfdietz 3y agoThe key is sufficiently cheap electrolysers. They are below $300/kW now. The other steps (if any) have higher capital cost/energy cost ratios, so they can be done when energy is more expensive.
- ftth_finland 3y agoCan you explain how the costs pencil out? Today, in Finland, renewables produced between 0,2 GW and 1,5 GW. Does that mean I would need $450M (1,5 GW * $300/kW) in electrolysers to soak up all that power? For simplicity's sake, let's say output averages 1GW over 24 hours? What do I get for the day with my $450M electrolysis plant?
- pfdietz 3y agoThere's a tradeoff between the cost of excess solar/wind and the capacity factor of the electrolysers. You can get a handle on where the tradeoffs lie by looking at optimizations using historical weather data. https://model.energy/ https://model.energy/ For Finland, the 2030 assumptions number (for "synthetic baseload" from renewables + storage) is just under their "EPR" number (which may be a bit optimistic, given your experience with an EPR). As I said, Finland is a tough case for renewables. The solution has > 400 MW each of solar and wind, and 110 MW of electrolysers (to provide 100 MW of synthetic baseload).
- fooblaster 3y agoThis was the most comprehensive study I have read: [300 page pdf - warning] https://www.google.com/url?sa=t&source=web&rct=j&url=https://energy.mit.edu/wp-content/uploads/2011/12/MITEI-The-Future-of-the-Electric-Grid.pdf&ved=2ahUKEwi14rz16bH_AhVMLUQIHabqA64QFnoECA8QAQ&usg=AOvVaw0R20YFdeI5BgklNJzJgNLz https://www.google.com/url?sa=t&source=web&rct=j&url=https:/... I have always been skeptical that grid storage was the hidden cost of solar, and that multiple weeks of total grid output storage were needed, but this makes convincing arguments that only a few hours of storage is needed, even in difficult areas.
- fooblaster 3y agoCrap, posted the wrong link earlier. What I meant to post was a different study from the same series. https://energy.mit.edu/research/future-of-energy-storage/ https://energy.mit.edu/research/future-of-energy-storage/
- ftth_finland 3y agoA few hours in nowhere near enough. In Finland solar produces no power three months of the year. The months before and after that are marginal. To add joy, there are windstill periods of days, sometimes more than a week, in winter. To add insult to injury, there isn't enough transmission capability to import all the renewable energy we would need to solely rely on renewables. There isn't enough hydro either so rely on that to take up the slack. So, grid storage really is the hidden cost of both solar and wind, and multiple weeks of total grid output storage is needed for energy security if relying on renewables. To reinterate, I really want to learn more about real long term storage. Anybody know where I can find solid info on that?
- fooblaster 3y agodid you read parts of the link at all?
- ftth_finland 3y agoYes, but it's 280 pages. Which parts in particular address long term storage? Searching for "storage" gives very few hits. This was perhaps the most pertinent hit: "IT IS GENERALLY NOT ECONOMICALLY FEASIBLE TO store electricity in bulk. The widespread deployment of new storage technologies and/ or high penetrations of electric vehicles may someday change this, but these developments are unlikely before 2030." along with this: "Compressed air energy storage (CAES) is the only other storage technology [other than pumped hydro] that has achieved long-term utility-scale operation. ... Only two utility-scale CAES facilities have been constructed worldwide: a 290 MW facility with two hours of storage in Huntorf, Germany, that entered commercial operations in 1978 and a 110 MW facility with 26 hours of storage in McIntosh, Alabama, that entered commercial operations in 1991." Not very much to go on, now is there.
- danans 3y ago> Most seem to think 4 hours qualifies as storage. It does in some places. In Finland (where I presume you are), it clearly isn't enough, but in warmer places like Texas and California and the huge swathes of the world that have sufficiently reliable renewable electricity resources that 4 hour storage could handle the intermittency.
- danans 3y ago> My state proposed a grid battery solution that would have provided power for the entire state for up to 1-2 days IIRC. They didn’t approve it, but the budget wasn’t astronomical. I honestly wonder if the worry about off hours use is a little overblown. Which state? Currently, the production scale battery tech that's available (LiIon, LFP), isn't really cost effective for multi-day backup. It's used for very short term (second to hour) and expensive demand response services (substituting for traditional natural gas peaker plants). The cost/kWh needs to be about an order of magnitude lower to make economic sense for multi-day backup. It's coming, however. There are several contender technologies: metal air, flow, and sodium ion. All of those have much better cost and safety characteristics than Li-ion, while trading off the energy density (which doesn't matter in grid scale stationary storage).
- pfdietz 3y agoAlso pumped hydro, pumped thermal, and resistive thermal. Resistive thermal in sand at 1200 C is projected (based on lab estimates) to have a LCOS of ~$0.05/kWh and a round trip efficiency of 53%.
- scythe 3y agoOne problem is that currently the mix of solar is low enough that grid storage has to be sold as "backup" or "leveling". Grid storage that is actually used will for obvious reasons have a better cost-benefit ratio. If you still have three times as much gas as you do solar, why would you buy a battery?