The simple fix of switching out old light bulbs to LEDs is making a major dent in demand on the nation’s power grid:

The nation’s largest grid, serving more than 61 million customers from Washington to Chicago, is revising its demand forecasts after recognizing that better lighting has undercut its projections. Swapping all of Thomas Edison’s incandescent lightbulbs with lamps containing light emitting diodes, or LEDs, would save enough electricity to power 20 million American homes, according to the Energy Department. …

Lighting accounts for about 5 percent of a home’s energy budget and switching to more efficient bulbs is one of the fastest ways to cut those costs, according to the Energy Department. LEDs use 75 to 80 percent less energy than incandescents and last 25 times longer.

LEDs will account for 83 percent of the lighting market share by 2020 and almost all of it 10 years later, the Energy Department says. The cost of the bulbs has fallen by more than 85 percent in six years, according to ACEEE, a Washington-based non-profit that promotes conservation. Bulbs are now available for less than $5.

This news comes on the heels of Ikea announcing its only stocking LEDs going forward in its stores.

While switching bulbs is a relatively simple, cost-saving upgrade, other retrofit methods, such as efficient appliances and better insulation will also help decrease demand. It’s certainly easy to focus on shiny new clean technologies, like solar and batteries, but ultimately we’ll need major improvements in efficiency to meet our long-term climate goals. The rapid uptake of these new bulbs makes for a great start.