Barroso said the commission would present a road map for the energy sector in January that included recommended measures to increase energy efficiency and broaden the use of renewable energy sources, clean hydrocarbons and, "for those who want it", nuclear energy.
"It is for the member states, not the commission, to decide on whether they use nuclear energy. But the community can make a contribution to those that want it, for example on research and on safety," he told an energy conference in Lisbon.
"We cannot hide from the issue. A debate on nuclear energy should not be taboo," the former Portuguese prime minister added.
Under European Union nuclear rules the European Commission, the executive arm of the 25-member bloc, must clear investments for building or renovating nuclear power plants.
The aim of the measures is to speed up the transformation of Europe to a low carbon economy, said Barroso, adding he hoped they would be adopted by member states at a summit next year.
The EU, the world's largest importer and second-largest consumer of energy, is unlikely to meet a self-imposed target to cut emissions of greenhouse gases which are blamed for climate change, he said.
"We are facing a serious and urgent issue. On current trends, climate change will have widespread consequences, on both developed and developing countries," said Barroso.
Under the 1997 Kyoto climate change pact, each member of the EU agreed to cut their carbon emissions by eight percent from 1990 levels by 2012.
Earlier on Monday a British government report by World Bank chief economist Sir Nicolas Stern warned that failure to act on climate change could devastate the world economy on the scale of the world wars and the Great Depression.
Barroso welcomed the report, saying it made an "important contribution", but he added the EU also needed to reform its energy sector to reduce its growing reliance on oil and gas imports.
"We are currently dependent on external sources for 50 percent of our energy needs. this could rise to 70 percent by 2030," he said.
"So Europe is being exposed to increasingly intense competition for global energy resources from other countries, and is becoming ever more dependent on oil and gas imports from geo-politically uncertain regions," said Barroso.

Copyright AFP (Agence France-Presse), 2006