Where will the shifting supply-demand curve take renewable energy in 2011? That question is being raised this week in advance of the fourth-quarter earnings calls of several solar giants — SunPower and Yingli Green Energy Holdings later this week, and First Solar, Q-Cells and JA Solar later this month. Analysts have been predicting less-than stellar 2011 projections, given the consistent downward pressure on module prices combined with shrinking government supports in Germany and France, as well as a potential bubble in Italy. Most hopes are on the United States, where growth could help cushion the European slowdown. At the same time, the ferocious price competition in solar panels — down more than half since 2007 — is making solar power less expensive compared to fossil fuel-fired resources like coal and natural gas. A similar path is being taken in wind power, where turbine prices have fallen to five-year lows in recent months. What’s hard for solar panel and wind turbine manufacturers can be good for solar and wind power developers, up to a point.