They work (as in: are being used in Africa & South America to power mobile networks). Also my (office) building is powered by one.
They don't cost much more than lead-acid
They last much, much longer than lead-acid or lithium*
There is no limit to the number of power cycles(!!) and they can be deep-discharged.
They do have disadvantages - they aren't suitable for cars, and are currently fairly noisy when cycling, and have lower power density than lithium* batteries. They also need to be periodically complete discharged (although most have software to make sure each individual cell does this as part of the normal use)
Disclaimer: An investor in Redflow owns my building (hence the power source)[2]
http://www.bluesky-energy.eu/project/redflow-zinc-bromide-ba...
From the wikipedia article, it appears that typical flow batteries only reach 10% to 20% of lithium polymer's power density.
That means that it would take a flow battery that weights 5 to 10 times as the standard lithium polymer batteries that equip a Tesla/Nissan Leaf/whatever electric car you imagine to deliver the same power.
Very true, but, interestingly, large-scale electric vehicle adoption may help this: http://thinkprogress.org/climate/2016/05/09/3775606/used-sec... as lightly used car batteries may cease being attractive for use in cars but be very attractive in terms of base-load storage.
There is a guy with videos on youtube who has purchased battery packs from crashed Tesla Model S and retrofitted an old volkswagon bus for 100+ mile EV range.
http://insideevs.com/diy-project-salvaged-tesla-model-s-to-u...
"Joe’s “donor” Model S will be brought back to life by Otmar in the form of a stretched Volkswagen Vanagon called Strechla.
The Vanagon will exist only on the outside. On the inside, underside and everywhere in between, you’ll find Model S."
edit: added more words
https://www.youtube.com/user/jehugarcia/videos
scroll down a bit into the older videos and you will see the VW.
And a battery trailer, inspected by the DMV.
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.
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.
As air conditioning, but there are other solutions! Ice has neigh-infinite charge/discharge cycles and big institutions have been doing this for years. If your "campus" is more than a few hundred tons of AC it's probably cooled by ice.
It's not been terribly economical to do this at a small scale but as solar gets cheaper and batteries don't there are people working on the problem.
Batteries, at whatever price you pay for them are a really in-efficient way to store and retrieve energy compared to the grid.
Off grid energy storage has been severely hampered by the lifecycle cost of $ per kWh stored. Lead acid batteries suck, lithium ion/liPo has until very recently been very expensive in $/kWh. Other energy storage systems have been limited in scale or are only feasible at very specific places, such as large scale pumped-storage hydroelectricity.
If the cost of $$$/kWh stored comes down far enough, it will be entirely possible to build a home that has no connection to the electrical grid at all. Assume this prototypical home is in an American city where electricity from the grid costs 8 cents per kWh. If you make a refrigerator sized battery low enough cost it may be possible with TODAY's cost of solar panels to have a lifecycle cost of 6 cents per kWh consumed. While simultaneously having the effect of making that home energy-independent from the grid and the whole thing being its own immense UPS.
The powerwall is the first step towards this.