Comment by _delirium | Hacker News Reader

Comment by _delirium | Hacker News Reader

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These kinds of utility-run storage facilities usually buy and sell on the wholesale spot market, which swings much more than retail prices do. Somewhat similar economics to gas "peaker" plants, which only fire up when supply is tight and prices spike, making it economical to run a higher-cost generator.

The Hydrostor plant is in Ontario. Here's an archive of hourly spot-market electricity prices there (in dollars per MWh): http://reports.ieso.ca/public/PriceHOEPPredispOR/. So far in 2022, prices have been as low as $0.00/MWh (during a few hours overnight on Jan 5) and as high as $230.87/MWh (during the morning of Jan 11). In 2021, hourly average prices even exceeded $1000/MWh ($1/kWh) twice, on March 28 and October 10.

I would need to see the math, because nothing adds up to even 1/10th of their claimed revenue. Best case, they bought 10mwh on jan 5th and sold it at the perfect time on jan 11th. This would give them 2k in revenue in 6 days.

Wheres the rest? And what about if you cant nostradamus predict the best times to buy and sell?

The other thing that they can be doing is selling standby frequency response services to utilities:

https://smartgrid.ieee.org/bulletins/january-2016/energy-sto....

Sometimes utilities only need a few minutes of power to cover small gaps while ramping up/down powerplants, or if a cloud passes over a solar generation facility. Since these volumes are very small but critical, the effective price per MWH is extremely high.

When Tesla did their grid scale battery installation in Australia, this is how they made their money. Not via energy arbitrage, but with selling frequency response services. I have no idea if this is the same thing, but there are other ways to make money with energy storage as well.

Still seems extreme. IF my math is right, they would need to buy and sell 10MWh every day at a 27c/KWh markup. Given they they deliver at ~2.2 MW, This means that they would have to hit this markup for a 4 hour duration, every day.

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