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!
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...
Most of my loads, on average, don't need to run that exact second.
I don't mind if my hot water tank super-heats water in the middle of the day for the rest of the day. If electricity is really cheap, my freezer can jump into overdrive.
I don't need my clothes to dry in the next hour, just over the next 8.
I don't care if my fridge/freezer takes a break while I run the microwave or pre-heat the oven.
I don't care if my car charges ASAP as soon as I park, as long as it's charged by 8AM. And let it run as a grid-power bank for a fee.
Then you could have A/C systems that make ice or compress refrigerant in a tank.
Then why not just hang them up for drying? Zero power consumption and they will dry in eight hours, maybe not under all conditions but under many.
I'd even go a step ahead: dryers ruin clothes.
A bit diff in a humid area, or where the A/C would need to condense the added humidity (if dried indoors), or the furnace would have to counter-act the cooling from evaporation, but HVAC is usually more efficient than the dryer.
Water does not have the capability to store much energy.
>If electricity is really cheap, my freezer can jump into overdrive.
Your freezer can't if it's not a ammonia refrigerant. You will actually be wasting energy.
>I don't care if my fridge/freezer takes a break
Your fridge actually does not use electricity constantly. It detects the temperature and run the motor, stops it when it reaches the desired temp. It's already having a break.
OK on the freezer. Could still take the fridge down to 2C.
The concept of the fridge taking a break while running other loads is to reduce peak draw current. If everyone did that, it would make the grid more stable.
Scheduling exchanges, where your local grid sub-station can get your bids for usage and put it into a grid wide exchange, scheduling your car to charge itself at 3:34 am using 24Wh or whatever.
We become ever more interconnected - this is the real rental economy - renting not a lawn mower for an hour but renting power. You think privacy is bad on your phone - wait till your washing machine sends "soiled underpants on at 3pm - any bids" to half the planets solar providers
- Washing machines (Replace the concrete with water balloon, choose latest time to complete)
- Lights (mostly I think these will be LEDs drawing off a panel on our roof. We don't need that much light.
- too tired to do this but a study on this must exist somewhere?
Improved efficiency is one of the things that allows us to have continued economic production despite reducing usage.
Let’s talk real. Compared to fluorescent lamp, LED comsumes half of energy. It’s not like they comsume nothing. Over 68% of sockets in American households already use LED in 2018 and 13% of energy was used in residential lighting in 2018. If 32% changes to LED it will lower the percentage to 11% which is still more than what we use to refrigerate.
In 2017, 1% of households had all sockets using LED and 71% had not a single socket using LED. 11% still had all sockets using incandescent. https://www.eia.gov/todayinenergy/detail.php?id=31112
Systems that make ice at night and use it for A/C during the day date back to the 1950s.
The general class of these facilities is phase-change materials. Water is pretty amazing, both for ice and for steam.
The future of low emissions energy production will be largely driven by overproduction and demand shifting, not banks of grid level batteries.
This likely won't happen as soon in America, however, the economy is too tied in to fossil fuels and the appetite to upgrade the electric grid by utility companies heavily invested in gas isnt really there.
>A startup run by a Tesla veteran and backed by Bill Gates is promising to build a long-duration battery that's 50 to 100 times cheaper than lithium-ion https://www.businessinsider.com/form-energy-battery-startup-...
Disconcerting.
even before reliable utility-scale storage, there is a lot of low hanging fruit from covering the southwest US in solar and wind. but yes, the costs of intermittent power like wind and solar doesn't by itself end with installation.
Don't worry -- every single time renewables are mentioned on HN, this aspect is at the top of the posting.
Modern Gas turbines can also act as a good backup for solar in times where there is unusual demand because they can start up on under a minute
For example, use solar power during the day to pump fluid from a lower reservoir into a higher reservoir, and then harness the energy of the water flowing from the higher reservoir into the lower reservoir through turbines.
As long as your output energy is always coming from the turbines, and as long as your solar powered pumps running during the day can keep up with double the rate of drainage flow, then you should have a constant loop with a steady supply of power.
This type of system could be retrofitted onto virtually any dam, giving you a way to create a closed loop with constant power and without the water loss typical from a dam (other than evaporation).
For areas where water is scarce and a dam isn't feasible, there are also other ideas, such as gravitational potential energy systems that use solar powered energy to lift weights on pulleys, which then power a generator as the weights are lowered by gravity.
Other ideas: Thermal storage including molten salts which can efficiently store and release very large quantities of heat energy, compressed air energy storage, flywheels, cryogenic systems, etc...
For one thing, existing dams absolutely cannot be converted to pumped hydro. Dams do not store water below them. Water flows downstream because a dam is in a river. There is no water to pump uphill. Unless, of course, you also build a second dam very close downstream to create another lower reservoir. This is usually a bad idea, and better to just find better geography that will support a new pumped hydro dam.
Sadly, dams tend to destroy healthy fishery ecosystems —- a side effect of not “wasting” the water.
Trying to rely only on intermittent power sources has huge storage requirements due to weather along with daily/seasonal variation. If grid energy storage was a simple problem it would have been done decades ago.
For example, one estimate is that for Germany to rely on solar and wind would require about 6,000 pumped storage plants which is literally 183 times their current capacity:
>...Based on German hourly feed-in and consumption data for electric power, this paper studies the storage and buffering needs resulting from the volatility of wind and solar energy. It shows that joint buffers for wind and solar energy require less storage capacity than would be necessary to buffer wind or solar energy alone. The storage requirement of over 6,000 pumped storage plants, which is 183 times Germany’s current capacity, would nevertheless be huge.
https://www.econstor.eu/bitstream/10419/144985/1/cesifo1_wp5...
Overprovisioning is so simple and widely accepted a concept that anyone ignoring it is likely trying to intentionally mislead.
Except storage is much less useful in the old paradigm, so the motivation wasn't there. Going forward, prices will swing wildly, so storage will be more valuable.
Plentiful storage would obviously have been very useful over the last several decades. There is a large variation in daily electrical usage (particularly in summer months):
https://www.eia.gov/todayinenergy/detail.php?id=42915
There is also the need for extra capacity in the system because of planned and unplanned maintenance.
>...Going forward, prices will swing wildly, so storage will be more valuable.
Well yes, our economy is based on having reliable power and it would be impossible to have anywhere near the reliable power relying on intermittent power sources without a huge amount of storage. The problem is that contrary to what advocates claim, people have been looking at grid energy storage for decades and it isn't as simple as they claim.
As Bill Gates said in an interview: "…They have this statement that the cost of solar photovoltaic is the same as hydrocarbon’s. And that’s one of those misleadingly meaningless statements. What they mean is that at noon in Arizona, the cost of that kilowatt-hour is the same as a hydrocarbon kilowatt-hour. But it doesn’t come at night, it doesn’t come after the sun hasn’t shone, so the fact that in that one moment you reach parity, so what? The reading public, when they see things like that, they underestimate how hard this thing is. So false solutions like divestment or “Oh, it’s easy to do” hurt our ability to fix the problems. Distinguishing a real solution from a false solution is actually very complicated."
https://www.theatlantic.com/magazine/archive/2015/11/we-need...
Gates is investing in 4th gen nuclear and energy storage companies so he is putting his money where his mouth is.
I'm still hoping for this one, just because it's so epic: the giant rock-piston gravity storage: https://www.heindl-energy.com/
"Utility scale solar" is ambiguous and can mean solar thermal or pv solar.
I think solar thermal might be a completely different animal that is not long-lived and not clean.
It might be a similar situation to where "renewable power" turns out to me mostly burning garbage or burning trees.
This documentary might be a little biased but also have some interesting insights: https://youtu.be/Zk11vI-7czE