The Promise Of Renewables

Nearly 80% of the world's energy supply could come from renewables by 2050 if governments adopt policies to accelerate deployment of these technologies, says a new U.N. report.

The report released on May 9 by the Intergovernmental Panel on Climate Change (IPCC) says government actions play a crucial role in the growth of renewable energy. But there is no one-size-fits all approach.

Instead, the report says, a combination of policies can be more effective and efficient. These include incentives for R&D, renewable energy quotas, favorable tax policies, rebates, and grants. Other examples are policies to help renewable energy developers locate projects and get financing.

"The report shows that it is not the availability of the resource, but the public policies that will either expand or constrain renewable energy development over the coming decades," says Ramón Pichs Madruga, cochairman of the IPCC working group that produced the report. He is an economist at the Center for World Economy Studies in Havana, Cuba.

Increasing renewables' share of the world's energy supply is important because it could help restrain the growth of greenhouse gas emissions from fossil fuels, the report points out.

The proportion of renewable energy deployed worldwide is likely to expand even if governments at local, state, and national levels don't enact new policies, the report says. But past experience shows that policies to encourage renewables provide bigger increases than doing nothing.

The report examined six types of renewables. One is bioenergy, which includes crops grown for fuel, agricultural residues, and livestock manure. A second is solar, such as photovoltaics and concentrated solar power, which involves mirrors or lenses focusing sunlight to heat water and create steam that drives a turbine. Another is capturing energy from the ocean's waves, tides, currents, and heat and salinity gradients. The other renewables covered in the report are geothermal energy, hydropower, and wind.

Deployment of renewable energy technologies in the future is anticipated to be highest in developing countries, the report says. Currently, developing countries are now home to more than half of the world's renewable energy capacity, it adds.