President-elect Barack Obama recently called for stimulating the economy in part by direct government investment in clean energy, specifically in projects “building wind farms and solar panels.” Through various “green” policies and investments, he hopes to create five million new jobs.

A new report from Deutsche Bank supports this approach. It argues that it’s possible to address challenges related to climate change, energy security, and the financial crisis at the same time by investing in four specific areas: energy-efficient buildings, electric power grids, renewable power, and public transportation. The report cites figures that suggest investing in these areas creates more jobs than investing in conventional energy sources because much of the old energy infrastructure is already in place. It says that “a $100 billion investment in energy and efficiency would result in 2 million new jobs, whereas a similar investment in old energy [such as coal or natural gas] would only create around 540,000 jobs.”

What’s more, the report continues, when the government invests in a project, other investors line up to invest as well. It “unlocks” private-sector funding and partnerships.

Detractors say that clean energy can have a negative effect on jobs, since it tends to cost more. If energy costs are high enough, it could force companies to cut jobs.