Davey touted the renewable energy drive led by the Scottish government of First Minister Alex Salmond during a low-carbon conference in Edinburgh.
Salmond said last year that the Scottish government wanted to meet half of its electricity demands through renewable energy resources by 2015. Scotland has one of the more ambitious renewable energy plans in Europe, aiming to generate 100 percent of its electricity needs through low-carbon projects by 2020.
Salmond scheduled a referendum for independence from the United Kingdom for next year. Davey said the future of Salmond's green energy ambitions was more secure if Scotland remained part of the United Kingdom.
While an independent government would be a responsible economic steward, commitment and the ability to deliver are two different things, said Davey.
"I am not absolutely saying that Scotland will not be able to compete," he said. "But it will be much harder for a nation potentially having to spread the costs of investment in renewables across just 2 1/2 million households to keep prices competitive."