Supporters are trying to duplicate successes in Europe, especially Germany. Christian Maass, Hamburg's Secretary for the Environment, looks back over 10 years, and says the program has worked well.

"Since we have introduced the feed-in tariff, we have seen a strong increase in the production of power from wind, from biomass and from solar power. Also, we have seen hundreds of thousands of jobs growing in Germany."

However, he acknowledges that Germans are paying a price for their renewable energy. Solar power, in particular, is much more expensive than other sources of electricity.

"But if you look at the price and if you look at the benefit and you compare that, it's worth it. So I can only recommend from the German experience that it's good, that it's something to copy from."

Utilities are allowed pass on their higher energy acquisition costs to consumers. And Hamburg resident Patrick Ulmer says Germans routinely complain about high energy prices. "Basically, what the consumer notices is that prices had gone up. That obviously is not a good thing. But I don't think that many people made the link to feed-in tariffs because of solar energy."

Economic storm clouds disrupt solar power

European incentive programs threatened to spin out of control when solar module prices dropped - decreasing producers' costs - while the rates utilities had to pay to buy that power stayed high. Investors flooded in to lock in high profits.