Solar Energy Calculations

DVader1000 is correct in the power output estimation. A friend is doing some measurements of output power on a solar panel during the day over the period of year, to take an average on the climate conditions. The values are typically as mentioned. The cost? Depends on your local supplier, vary toooooo much depending on country, taxes, dolar quotation in the day, ... But I'd say that it is going to cost at least USD800,00 per panel, plus controller, contactors, batteries, wiring and assembly of all stuff. Its absolutely not cheap. That's why not already spread, not talking about batteries life and recycling. Prices of solar panels are dropping, and I really hope we can all play with them in home made systems for backup or maybe selling...

I vaguely remember that the average solar radiation (insolation) is around 300 BTU/sq ft per day for this latitude (~ 35 deg N). Given efficiency of converting heat/light to electrical power as suggested above, one may get an idea of how much energy of any sort one may get for a given size of solar collector.