May 14, 2009

Shade trees can save much home energy

Scientists at the U.S. National Institute of Standards and Technology say shade trees planted near homes can significantly affect summertime electricity use.

The researchers and their colleagues at the U.S. Department of Agriculture said their study -- the first large-scale study of its kind -- focused on the effects of tree shade at 460 single-family homes in Sacramento during the summer of 2007.

The researchers said they discovered how well-placed shade trees can reduce energy costs and atmospheric carbon, as well.

People have known for a long time that trees have multiple benefits for people, but we've quantified one of them for the first time using actual billing data and put a dollar value on it, said NIST's David Butry, who authored the research paper with Geoffrey Donovan of the USDA.

The scientists noted they found planting trees on the west and south sides of a house decreased summertime electricity use, but planting them on the north actually increased it. Those on the east had no effect.

The findings are detailed in the June issue of the journal Energy and Buildings.