Too little, too late unfortunately. The amount of storage available from these projects is tiny and even though it's accelerating it's not accelerating at nearly the level required for the physics of a primary renewable grid to work. Chemical storage of energy is expensive and requires a long supply chain. It's huge that the costs are trending in a favorable direction and maybe eventually we can do all our load balancing that way but we don't need results 15 years from now, we need them yesterday.
No one technology is accelerating fast enough. But I think battery storage has amazing potential for scalability. It is very suitable for mass production in a factory and produces small components that are relatively fungible. Battery storage sites can be built anywhere, require little civils works, have tiny environmental impact and are very quick to install. And they have the benefit of research and production for cell phones and cars. Massive scalability is hard to predict in advance but is definitely possible. Look at how many billions of arm chips are shipped every year.
We definitely do need pumped storage. Although big civil engineering projects tend to be slow and expensive in most developed economies. And how much of the world actually had the right terrain? My guess is that we will see a few massive projects at one end of a HVDC link rather than scaling up.
Is this supported by the report though? We have yet to build most of the solar we need, and IIUC almost half of new solar is now being built with storage:
> At the close of 2021, there were more than 670 GW of solar plants in the nation’s queues; 285 GW (~42%) of this capacity was proposed as a hybrid, most typically pairing PV with battery storage (PV+storage represented nearly 90% of all hybrid capacity in the queues).
This is the surprising fact for me from that report. Of course, “built with some storage” is not the same as “built with 100% storage” but the report shows the distribution is not terrible, with ranges of 50-100% storage being built. (With %age being something like “daily maximum variance from demand curve” but I don’t understand exactly how this is computed).
My impression is that most "PV+storage" plants have storage enough to handle uneven loads and production rates on maybe hour timescales during the day. The storage required to provide overnight supply, though, is much larger, not to mention that required to handle seasonal variance in PV production. It seems hard to imagine batteries would provide that, but for that maybe the most cost-effective option is to just size the PV capacity for the worst-case season.
Given the evolution in PV cost, maybe it will be cheaper to size PV production to worst-case days rather than size it for an average day+storage? You'd still need sufficient storage for overnight consumption, obviously.
I previously shared your impression but this report seems to suggest otherwise; see p24 in particular:
> • Battery:PV capacity ratio always at 100% in HI; lower on the mainland (but increasing over time—see bottom right graph)
• Storage duration ranges from 2-8 hours; 50 of the 61 plants have 4-hour duration (other 11 are 5x2 hr, 1x3.7 hr, 4x5 hr, and 1x8 hr)
And there are some detailed case-studies that give other examples too:
The first one (Pine Grove substation) gives a sort of "emergency button" to provide 12 hours of load relief, when they call it in. This seems like it's basically just shaving off extra load that occurs on particularly busy days (~40/year), it's not solving the core demand-curve mismatch. (It looks like the batteries function as essentially very-short-term demand smoothing/arbitrage when they are not being called in).
The second one (Wheatridge) is 4H of 30MW (~10% of the power of the whole facility); I don't have a feel for whether this is closer to the full demand-curve mismatch.
Edit to add: There's actually another case study that might be even better, Slate PV + storage plant in CA, which is ~50% power for 4 hours, which is very substantial.
I think you're right that you can't store much energy overnight -- but that's not really required I believe. My understanding is that if you have a mix of solar and wind in your grid, you tend to be fine overnight since it's always windy somewhere at night. The challenge for solar&wind is supplying the afternoon/early-evening peak.
Previously you'd conceptually have "baseload" which is sized at the daily minimum, and then "peakers" (or these days just rapid-dispatch gas) which are turned on as needed to supply the daily peaks. With solar this isn't an option; the supply curve is fixed. So you either have to massively overbuild to have enough generation to meet the demand peaks, or have some way of shifting the peak solar generation (midday) to the right, to match the peak utilization. So I think your storage ends up needing to look more like "store 25% of the midday generation to be used by 6pm" (numbers made up for the sake of example). Which seems to be the OOM that these projects from the report are achieving.
Windgas is actually pretty suitable for that last 1%. It may be 50% efficient to produce but it's easy to store large quantities of gas for long periods for those dark/still spells.
Counterintuitively that 1% of electricity generated from windgas will among be the most expensive "green" electricity but it will probably still be cheaper than nuclear power:
If you want to eliminate Carbon emissions, you do. The electricity supply network is always built for overcapacity or else bad things happen with frequency and device damage
> Data on plants under development from the interconnection queues of all seven ISOs/RTOs plus 35 individual utilities suggest that these hybridization trends are likely to continue. At the close of 2021, there were more than 670 GW of solar plants in the nation’s queues; 285 GW (~42%) of this capacity was proposed as a hybrid,
Perhaps I'm mis-interpreting this (not my field), and it's plausible I suppose that these projects won't get approved uniformly. I'd be happy to get more clarity on this if the report is actually saying something different. (I acknowledge my original phrasing could have been better, the way I wrote it suggests "solar that has just been built" vs. "solar that is currently planned to be built". But I don't think that's the source of your surprise, it's surprising because batteries are supposed to be uneconomical any time soon.)
Anyway, if I'm interpreting this correctly it seems like quite big news; I certainly shared your priors/skepticism on battery storage prior to stumbling across this report.
PV should enable distributed power generation. I'm not saying grid storage, grid generation, and grid hydro isn't needed, but home solar should be a strong focus of policy.
The cost differentials are basically all down to labor, which is generally locally captured.
The "long supply chain" of batteries isn't true. We don't need cobalt or nickel for grid. Sodium Ion is going into mass production in China, and LFP is topping 200 wh/kg. Hell,you don't need cobalt or nickel for EVs anymore, a 300-400 mile car should be easily doable with the current state of the art LFP, and 200-300 doable with sodium ion.
Hydro storage is very very efficient (thanks to all the engineering that went into hydro dams), I think it's in the 90%+ for efficiency. It definitely should be a major part of our energy plans, but this thread makes it seem like it's the only practical way, and uses pumped hydrogen as a straw man competitor.
We need grid wind, gridsolar, geothermal, keep the nuclear, hydro, home solar, home storage, chemical batteries ... all of it. But the cost profile of wind/solar is already better than natural gas turbine, and I'm hoping wind/solar+batteries will pass everything in 5 years with sodium ion, but I don't have numbers on that.
This two weeks storage is ridiculous. With good home solar buildout, that is not needed.
