Compared with eye-catching renewable power technologies like wind turbines and solar panels, energy efficiency is nearly invisible. But advocates say doing more with less power may be an even more critical weapon in the fight against climate change and offers big economic benefits, too.

Worldwide, governments, companies and families could be saving trillions of dollars by improving efficiency with cars that go farther on less fuel and improved appliances, light bulbs and factories, experts say.

“It’s logical, because we simply waste so much,” said Harry Verhaar, head of global and public affairs at Philips Lighting and chairman of the European Alliance to Save Energy. “Some people call energy efficiency low-hanging fruit. I would even say energy efficiency is fruit lying on the ground. We only need to bend over and pick it up.”

Realizing those energy savings would be a huge boon to the climate, ease illness-causing air pollution, reduce many nations’ reliance on fuel imports and increase competitiveness by lowering costs, the advocates say. It creates jobs in fields like upgrading buildings, and is generally cheaper than the alternative of constructing new power plants and buying more energy, they argue.