Electric car batteries can endure thousands of full cycles before their useful capacity drops down to 80%. That figure can be as high as tens of thousands, depending on who you ask.
Suprisingly, for LiMn, temperature and age have a much greater effect on lifetime than cycles.
PS: The real advantage of hydro is you can invest in capacity or peak load as more or less separate things.
5.5 years is about the lifespan of servers in a datacenter. What's wrong with managing energy storage the way we manage datacenters? We don't expect servers to last 20-50 years. And no doubt, as battery tech improves, the lifespan will improve too. But the infrastructure to get good storage needs to start somewhere. Run them as datacenters for now while waiting for battery tech to get better.
Don't forget computer investment has long operated under the assumption of rapidly declining prices. With that slowing data centers may go to a 10+ year cycle.
I agree with you on hydro, gravitational storage is relatively simple to do. But it takes space. Batteries could make more sense for microgrids.
That 200 mile charge may still be perfectly usable in a house, particularly given you can fit a couple cars worth into your basement without issues. The resulting battery cluster doesn't have to be particularly compact or light-weight.
The real question is "how much space are you willing to sacrifice for energy self-sufficiency?"
In the UK, electric bills hover around $1200 a year for electric/gas households and $2000 a year for full electric.
Renewable households will have a HUGE potential market.
U.K. Residential market is 26 million houses. Theoretical price point of $1500 dollars (one years energy cost) = 39 billion dollar market not including the massive combined secondary services in maintenance, installation training providers, parts, etc.
USA residential would be 6 times that and the provision of renewables to corporates is almost incalculable.
It's an entirely new economic ecosystem divorced from petrochemical.
It a price point higher than $3000 dollars we are getting into a market cap of many trillions worldwide.
I had a 3.8kW solar system put in for £5k last year and have yet to really run the numbers on savings; the payback period is 10 years of feed-in tariff cheques. If I went off-grid that would be reduced. I don't really see why I'd want to go off-grid for its own sake, I'd rather better explore the possibilities of net metering and sharing power with the rest of the city.
I am too lazy to put numbers on this, but this cost is currently much too high to make it economically viable to use car batteries for energy storage.