Cameron addressed delegates at an energy summit in London. Though the British economy has slipped back into recession, the prime minister said growing demand for energy meant the global economy was gaining steam.
He said global energy demand was expected to increase more than 40 percent in the next 20 years.
Because of this, he said, "we urgently need a more diverse, cleaner mix of energy sources that will give us energy security without causing irreparable damage to the planet."
He said that while nuclear energy, shale natural gas and other forms of clean energy alternatives had a role to play, renewables like wind and solar power were becoming more dominant.
"As a result, renewables are now the fastest growing energy source on the planet," he said.
The next challenge, he said, was making clean energy financially sustainable. To do that, renewable energy needed to be a global business.
"Then we really can secure the future of renewables, alongside other energy sources, as a vital part of our energy supply," he said.