On the storage issue, at ~100$/kWh batteries that do a conservative 1,000 cycles are ~10c/kWh stored + generation costs + conversion inefficiency. Take current unsubsidized grid solar prices of 2c/kWh solar and double that for 4c/kWh as a conservative redundant safety margin. Tracking solar for example has much better morning and evening generation though at slightly higher prices.
If 2/3 of your electricity is at 4c/kWh and 1/3 is at 15c/kWh that’s 7.7c/kWh for pure solar 24/7 including peaking power needs. Obviously a specific mix of generation determines storage needs, but those are also really pessimistic estimates.
PS: Hydro power is 6.1% of the total U.S. electricity generation. If 80% of that is released at night that’s a huge reduction in storage needed. Similarly transmitting power east or west makes a large difference in storage needs.
Bath County, VA: capacity 24GWh, since 1985
https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit...
Dinorwig Power Station, Wales: capacity 9.1GWh
https://www.theregister.co.uk/2016/05/16/geeks_guide_electri...
Worldwide, today
https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroel...
In some news article they say Energy Vault uses 35-ton blocks hoisted up to ~150 m - while it sounds impressive, that's only 14.3kWh (assuming 100% conversion efficiency), or about 1/7 of a single Tesla Model S (100kWh).
As another poster said, gravity is relatively weak compared to the other forces.
Is there an existing model for retail intraday rates? Would intraday rates be desirable for all market participants?
"Add area for curtailment data?" https://github.com/tmrowco/electricitymap-contrib/issues/236...
Also, while storage would be helpful, it is not the only way to enable a renewable transition. Additional transmission is enormously helpful: as the sun goes down on California, the wind is picking up in the Midwest. And don’t forget demand response: if smart thermostats received price signals (maybe we should precool this house...) that would alleviate the evening ramp-up issue.
So I claim we’ll need less storage than “a whole day’s usage”. But the learning curve applies to batteries as well! This storage won’t cost as much anyway.
The whole issue of intermittency is overrated. While a single solar panel might generate intermittently, the solar fleet across a whole state generates more predictably.
I am predicting that grid emissions will come down a lot over the coming decades. Partially I’m predicting the past: they’ve already come down, a lot!