LONDON — Here is a trick question: Which country led the European Union last year in putting new solar panels on rooftops and in countryside energy parks? If you chose sunny Spain or balmy Italy, you were wrong. Britain, the green and pleasant land often shrouded in cloud, was the leader, according to the market research firm I.H.S.

Britain, like other countries in the European Union, has pledged to sharply cut carbon dioxide emissions blamed for global warming. In practice, that largely means encouraging electric power generation from green sources like wind, which Britain has in abundance, and solar, a resource in which it is less well endowed. “Britain is the hottest market right now,” said Josefin Berg, a Barcelona-based analyst for I.H.S.

In part, Ms. Berg said, Britain’s solar boom is being artificially stoked by generous government subsidies. But solar, perhaps to a greater extent than other renewable energy technologies, has also seen a dramatic fall in costs, on the order of more than 60 percent over the last five years. That makes it worth considering as an energy source in places like Britain where investors and developers would have scoffed a few years ago.

”There is quite a lot of solar being built in the U.K.,” said Rory O’Connor, head of renewable power in Europe for the investment firm BlackRock. “This really demonstrates how far the industry has come.”