Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

Are solar cell panels and wind mills worth the money?
To answer the investment aspect takes a bit of math. First, solar insolation numbers:  This represents the average sun-hours per day for a given area. You can see the range from 4 to 6, or 1460 hrs to about 2190 hrs of sun per year depending on location. I believe electricity also has a range of cost, but 15 cents per KWH is a good average.  So, a 1KW panel will produce as much as $328 per year of electricity in a high sun-hrs area, but only $219 in a lower sun-hrs area.  If we agree to ignore the government subsidies and look for the stable price unaffected by outside influence, an installed price of even $2500 would produce a return of 13% and a reasonable full payback over an 8 year period.  I call this installed price a tipping point, the price where this purchase provides a decent return. Some would accept a lower return, and therefore a higher price. As duff points out, this should be treated as the post rebate/tax credit price. Those help to push the price below this point. At the price point where the energy cost per panel is below, the government intervention may be unnecessary. The power companies may find consumer owned panels are the cheapest way to clip the peak consumption which tends to be the most expensive power demand.) One can take the insolation numbers and cost of local power to produce a grid showing the return for a 1KW panel in $$/year. (At this point the cost of money kick in. The present value of $100/yr is far higher today than if short term rates were say, 8%)  Once panels drop to where they are compelling for the higher return areas, I'd expect volume to drive continued improvements in cost and better economies of scale. Initially, the need for storage isn't there, as the infrastructure is in place to drive your meter backwards if you produce more than you use. The peek sun coincides with peek demand and the electric companies are happy to have your demand go negative during those times.  Update - the conversation with Duff led me to research 'demand charge' a bit more. You see, the utility company has to have equipment to generate the peak demand, usually occurring in the early afternoon, say 12N-2PM as the sun is brightest and AC use in particular, highest. I found that Austin energy has a PDF describing the fee for this. Simply put, the last kW of demand will cost you $14.03 in summer months and $12.65 in winter. This adds to $160/yr that a 1kW panel might save the owner. Even if one does capture the full power at peak every month, $100 is still non-trivial. This factor alone justifies $1000 worth of panel cost, and as Duff points out, the government may find it cheaper to use this method to clip peak demand than by funding bigger power generators.  To summarize, the question isn't so much "are they worth it" as "what is a xKW panel worth?" (A function of annual savings and time value of money.) The ever decreasing installed cost for a given system makes solar an inevitable part of the future power technology. I am not a green tree hugging guy, but I do like to breathe fresh air as much as anyone. I'm happy with whatever role solar plays in cutting down pollution.