Energy-efficient light bulbs are more expensive and less available in high-poverty urban areas than in more affluent locations, according to a new study.

Researchers explored disparities in the availability and price of energy-efficient bulbs by surveying 130 stores across Michigan’s most populous county.

They found that the cost to upgrade from a conventional incandescent bulb to a highly efficient light-emitting diode, or LED, was twice as high in the highest-poverty areas. At the same time, the price for less-efficient incandescent and halogen lamps (IHLs) decreased as the poverty level increased.

Those disparities could lead residents of poorer neighborhoods to continue buying IHLs and miss one of the simplest ways to cut home energy bills: residential lighting upgrades.

“The light bulb price and availability patterns we found point to potential barriers to the adoption of energy-efficient lighting in higher-poverty neighborhoods,” says lead author Tony Reames, assistant professor at the University of Michigan School for Environment and Sustainability and director of its Urban Energy Justice Lab.

“The ability to benefit from the transition to more energy-efficient lighting is not equitably distributed, and those disparities raise energy justice concerns.”

In the US, lighting accounts for about 20 percent of the average household’s energy bill, and residential lighting is undergoing a rapid transition to increased energy efficiency. But for many households—especially the poor—the upfront costs of upgrading from an incandescent or halogen bulb to more efficient compact fluorescent lamps or LEDs is a significant barrier, researchers say.

High-poverty neighborhoods often lack large retail chains that sell products at lower prices and are instead associated with small retailers that generally sell at higher prices. And households in high-poverty areas often have less access to personal vehicles so are more dependent on the offerings of nearby stores.

Read more at Futurity