Last summer, Spain abruptly capped how many systems could sign up. In Germany this winter, the governing Christian Democrats proposed steep rate cuts to try to balance the market. Shares in solar energy companies promptly plummeted worldwide.

In the U.S., electric utilities lead the opposition to copying this rate structure, and to mandating purchases of alternative power. Dave Warren of the Washington Public Utility District Association notes electricity demand fell during the recession and may stay down, thanks to conservation. And then, "we would be forced to buy power that we don't need and idle existing generation or have hydro[power] that is very cost effective -- very cheap, actually -- being replaced by very expensive power." He adds it is ratepayers, not taxpayers, who shoulder the cost of this renewable energy incentive, and any rate increases are "tough to swallow," especially now.

In Germany, the above market price paid to wind and solar farm owners adds about two to five Euros to the average household's monthly power bill. Dave Warren offered a wide range for how much a similar policy might cost American consumers. He estimates rates in his home state could go up by as little as 0.03 percent to as much as 15 percent, depending on how many customers a utility company has to spread the costs across.