Interesting! But 50kWh seems pretty small for (macro-) grid applications. How big are these units? Seems like most grid installations would want on the order of hundreds (~10MWh) to a few thousand (~100MWh) of these.
The focus is on microgrids, but they're modular and can be installed below grade so you can add as many as needed. Approximately 2m diameter by 1m tall.
We're still working out costing, but it might even make sense for residential use to take advantage of time-of-use rates or energy arbitrage. Other applications are industrial processes that require high power for short periods.
Cool! I'll definitely be following your progress with interest :)
Hopefully constructive feedback: I would put that residential thing further down on your list. I think that stuff tends to be too complicated unless / until you can aggregate a lot of loads (eg. I think Tesla only recently recently started doing this stuff residentially. Probably awhile before you reach their scale...)
I hope flywheel storage takes off (no pun intended) it seems such a logic solution when compared with water elevation or chemical solutions. Why hasn't it gone mainstream yet?
I remember being really hyped about flywheel energy storage... 20 years ago. I wonder if it has become more viable since then? And if so, what changed to improve viability?
In the past they have been made to work, but they were not much better than batteries. With the price of batteries dropping like a stone I suspect they are going to have an even harder time competing.
There are several differences from batteries. Generally the benefits are faster charge and discharge rates, unlimited cycles without degradation, no lithium or rare earths needed, and wider operating temperatures.
They are not good at long term storage though, as the self discharge rate is high. And historically they have been expensive.
They have become more viable thanks to higher efficiency motors/power components and magnetic bearings, among other things. The biggest drawback is still cost, which is what we're tackling.
(on a smaller scale, to date, Tesla has deployed Powerwalls and Powerpacks at more than 50,000 sites worldwide; their Lathrop, CA facility is ramping to manufacture 40GWh/yr of capacity)
Two things:
(1) Price signals have to be further clarified especially at a utility level for ancillary services
(2) Battery system prices have been dropping quickly mainly as a function of Chinese manufacturers building out quickly e.g. CATL. Tesla is also helping.
Competition is already there - its next how do you deploy your development costs for winning those assets.
Dual feed power line, one for home electrics, one for immersion heater. Store excess renewably generated energy in household hot water tanks during the day, to be used in the evening in place of fossil-fuel generated supply, which also evens out load peaks as a side effect. This also works well with home solar.
I think grid load management for water heaters is already fairly common. I've basic versions of the concept in use by a coop in South Carolina, and I can't imagine them being anywhere near the bleeding edge.
The Seebeck effect will definitely have less than 8% efficiency with 80C water. Perhaps GP means that the hot water will already be available to use for hygiene and laundry, which for those with an electric water heater, is a large portion of the household power draw.
I'm not sure if a household sized water tank-full could provide heat over the course of a cold night, and whether a heat exchanger for air heating or water pipes would be more efficient. I suppose it depends on the insulation and placement of the ducts and pipes and how much of the heat makes it to and through a wall.
I did some very crude calculations but assuming 50 gallons at 60C and 1000W energy loss per hour from a moderately insulated house on a 50F night, the full water heater could keep the house at 70F for 5.14 hours. Someone with more recent practical physics usage is welcome to check this figure.
Not at all. Peak shaving with approaches like this is fairly common with utilities. Lots of them will give huge rebates on smart meters in exchange for this.
The energy difference between ambient-temp-to-frozen and ambient-temp to steam is much larger. I would think that this affects scalability.
I live in a city center that uses chilled water for some use cases, but it certainly does not seem scalable enough to be an "easy technical remedy" to the issues of distribution being expensive.
