[gonzy]

At the current cost of solar panels($3-$5) per watt assuming an average daily usage of 20000 watts(20kwh) I would think the minimum amount of panel required would be 2000 watts at a cost of $7000 plus all the control equipment req'd you are probably talking an initial investment of at least $10,000. Assuming a savings of $50 per month that requires a 200 month (17 yr) time frame to break even and thats generous because I doubt the solar panels would put out 2000 watts over a 10 hour day for 17 years. If solar panels get to the $1 per watt price range that would make the whole program a lot more sensible. A much more sensible economical approach at the moment would be to use solar hot water panels or batch heaters for hot water. They are relatively inexpensive and require very little in the way of control equipment.