Storing solar energy?

I know you said "in theory," but most of the question is on practical matters, so I'll answer that way.

A 250 watt peak panel is more likely to deliver about 220 watts, given the way the rating system works for panels. Also, peak sunshine is not the number of hours that the sun is out. Even in the summer in California where I live, when the days are 16 hours long, we only get 6 hours peak sun.

Also count on losing 25% of the energy, just in the inefficiencies of charging and discharging a battery.

Lead-acid batteries are the typical choice for cost reasons. This type of battery will be damaged if allowed to discharge too far, so you probably would not connect a fridge to such a small system, only things that are non-critical, and you could turn off at any time. Either that, or you would have a much larger system.

deep cycle batteries are measured in amp hours at their voltage. SO, 2 100 amp hr batteries at 12 volts will store about all your energy. The problem would be they would only last a year, so the normal design is to use 50% capacity, so you will need 4 of them. Also, you'll lose maybe 10% of your energy in the system

A TV and a light use about 250 watts, so they could run for 10 hours.

refrigerator runs about 1000 watts, so the refrigerator could run 2.5 hours which would keep food cold for at best 8 hours.

Finally, you can't get 10 hours at peak power, 7 at best in July and 4 at best in January.

Using H2, water, compressed air, you will lose over 60% of your energy, so, they should not be considered.

10 hours of peak sun light? Not anywhere on Earth?

Ok lets assume you can get 250 Watt for 10 hours. That is 2.5 KW hours. You will need at least 10 typical deep cycle battery's URL below.

Your typical deep cycle is 35 Ampere hours.

12Volts X 35 Ampere Hours = 420 Ampere hours. 10 battery's will give you 4.2 KWH. Yes that gives you some over capacity but you will want some as the battery's will lose capacity as they age.

You've identified one of the real weaknesses of solar energy - when the sun stops shining, the solar panels stop producing electricity. The second problem is that it is very difficult and expensive to store electricity.

There are several ways to store the electricity, but none of them are very efficient. On a small scale, try 12V deep-cycle lead-acid batteries. Other ways are to compress air, pump water uphill, heat up water, and produce hydrogen gas with an electrolysis circuit.

Homemade Solar Power Videos : http://solar.eudko.com/?jWZ