How many batteries will you need to store 1 mega watt power?

You don't store power. You store energy. The megawatt is a unit of power, which is a rate of delivering energy. So to draw an analogy to water, you are asking how big a tank of water do I need to store a million gallons per minute. A car battery typically has 50 Amp-hours. read more

Meaningless question. You don’t store power. You store energy. The megawatt is a unit of power, which is a rate of delivering energy. So to draw an analogy to water, you are asking how big a tank of water do I need to store a million gallons per minute. A car battery typically has 50 Amp-hours. read more

That means we need to store 1,600Ah. Let’s now assume that we are storing this in cells with a nominal voltage of 2V (lead-acid), then we will need 500 cells in series, each of 1,600Ah capacity. Too many assumptions — but I hope this gives an idea of the scale of such a system. read more

If you used an akaline battery (like AAs) it has a lower energy density at around 1.8 MJ/L such that it would be slightly larger house battery (but not rechargable). You can look at the Wikipedia page on energy density to get an estimate for house batteries of different materials. read more