I would imagine that the best batteries would be reservoirs. Take two spaces that hold water. One at high ground and one at low ground. Pump the water from low ground to high ground when energy is plentiful and let it run through generators when you need energy. Yeah, there is going to be energy loss, but this approach should scale to the quantity of energy necessary to provide the same amount of energy as a power plant for 12-24 hours.
For a consumer though, a single KW (3.6MJ) of power would be generated by moving 10m^3 (i.e. 10KL) of water 36m (approximating gravity at 10ms^-2). You can tweak those numbers but you end up needing two sizable water tanks quite far apart. Great if you have loads of land but not much use for consumer storage.
Feel free to correct any flaws in the calculations, I'd be much happier if I were off by an order of 10 or more.
There are several large pumped-storage plants in the USA too. They can provide about 2 GW for one day, enough to completely power a city of 1M people, or to smooth out supply fluctuations for a much larger region.
There's a second benefit to this approach in that you could use potable water tanks and fully sealed piping. This would provide many people with water to use in the event of an emergency. Obviously they would need to balance the needs of water with its utility as a way to store energy, but so long as you conserve both in the event of a disaster, you should be able to replenish what you've used via rainwater if the system is set up to collect rainwater and filter it (except in dry areas or during a drought of course).
How long would 1 KW last for the average household, and, if 1 KW is not enough, how many cubic meters of water would the average household have to store?
How long 1 kilowatt hour would last is a difficult question - depends on how efficient the home is and what tasks need to use that energy (for example, AC is very expensive but tends to be needed most when solar energy is available). Heating and cooling are most expensive.
Our energy usage in a not particularly well insulated home but in a subtropical Spring averaged about 9kWh/day - so 1kWh (3.6MJ) wouldn't get us far - it probably barely powers the fridge! However, you'd only need the storage overnight, and use solar energy the rest of the time. In sunny climes, at least.
Again, how much water depends on how much vertical drop, but it would likely be a lot of water (if you sat one cubic tank with 4.4m sides on top of another then emptying the top into the bottom would theoretically generate 1kWh)
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I would imagine that the best batteries would be reservoirs. Take two spaces that hold water. One at high ground and one at low ground. Pump the water from low ground to high ground when energy is plentiful and let it run through generators when you need energy. Yeah, there is going to be energy loss, but this approach should scale to the quantity of energy necessary to provide the same amount of energy as a power plant for 12-24 hours.
Dinorwig power station in North Wales does this. http://en.wikipedia.org/wiki/Dinorwig_Power_Station.
For a consumer though, a single KW (3.6MJ) of power would be generated by moving 10m^3 (i.e. 10KL) of water 36m (approximating gravity at 10ms^-2). You can tweak those numbers but you end up needing two sizable water tanks quite far apart. Great if you have loads of land but not much use for consumer storage.
Feel free to correct any flaws in the calculations, I'd be much happier if I were off by an order of 10 or more.
There are several large pumped-storage plants in the USA too. They can provide about 2 GW for one day, enough to completely power a city of 1M people, or to smooth out supply fluctuations for a much larger region.
https://en.wikipedia.org/wiki/Raccoon_Mountain_Pumped-Storag...
https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta...
https://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power...
There's a second benefit to this approach in that you could use potable water tanks and fully sealed piping. This would provide many people with water to use in the event of an emergency. Obviously they would need to balance the needs of water with its utility as a way to store energy, but so long as you conserve both in the event of a disaster, you should be able to replenish what you've used via rainwater if the system is set up to collect rainwater and filter it (except in dry areas or during a drought of course).
How long would 1 KW last for the average household, and, if 1 KW is not enough, how many cubic meters of water would the average household have to store?
How long 1 kilowatt hour would last is a difficult question - depends on how efficient the home is and what tasks need to use that energy (for example, AC is very expensive but tends to be needed most when solar energy is available). Heating and cooling are most expensive.
Our energy usage in a not particularly well insulated home but in a subtropical Spring averaged about 9kWh/day - so 1kWh (3.6MJ) wouldn't get us far - it probably barely powers the fridge! However, you'd only need the storage overnight, and use solar energy the rest of the time. In sunny climes, at least.
Again, how much water depends on how much vertical drop, but it would likely be a lot of water (if you sat one cubic tank with 4.4m sides on top of another then emptying the top into the bottom would theoretically generate 1kWh)