The government has at its disposal a number of tools to encourage development of clean energy sources. Congress could release additional funds to research institutions, attach requirements to state funding, change federal permitting standards, etc. Unfortunately, we're still waiting on a comprehensive energy policy that would utilize all of these tools, so in the meantiem we must make do with tax credits.
Already these tax credits have been effective at encouraging the growth of renewable energy. Big box stores have begun installing solar panels on the roofs of their buildings to offset their energy needs. Nationwide, there are 22 major solar power plants in the planning phase.
Yesterday the Associated Press reported that the Senate has broken a months-long impasse on a tax break package that would include the renewable energy tax credit. Legislation including this tax break package should hit the Senate floor this week. The Senate has set aside $17 billion in clean energy tax incentives, the funds for which would come from freezing tax breaks for oil and gas companies.