Solar energy is critical to any serious effort to mitigate climate change, yet accounts for only about one percent of U.S. and global electricity production.

That's according to a report published by the Massachusetts Institute of Technology (MIT), which concludes U.S. policy makers must change their approach to solar research and development.

Unless a substantial price is put on carbon dioxide emissions, expanding solar output to levels needed to fight climate change will be cost prohibitive without major change in government policy, the research concludes.

Get Breaking News Delivered to Your Inbox

The past few years have seen rapid growth in installed solar generating capacity, improvements in technology, price and performance, and the development of creative business models spurring investment in residential solar systems, the researchers found.

Both photovoltaic (directly generated electricity) and concentrated solar power (which makes use of the heat solar radiation generates) are increasing in use in homes and commercial buildings.

But, to date, solar has been a small part of non-hydro renewable electric generation, according to researchers at the University of California, Berkeley.

Expense is one culprit, although a 50 percent to 70 percent drop in photovoltaic prices, as the MIT report notes, has helped push use of the technology. Other difficulties with solar including the fact that home-based systems are 80 percent more expensive than a utility-scale plant.

Policies to support solar should include higher subsidies to utility-scale generators, the report concludes.