CHARLESTON, W.Va. -- I read the results of a study recently published by Auburn University's School of Forestry and Wildlife Sciences. Yes, there's a personal connection here - my son's a wildlife sciences major at Auburn. With that disclaimer, I must say it was interesting and informative.
Professor David Laband found that electricity usage and costs are 11.4 percent less if a house has just 17.5 percent heavy shade coverage. This is compared to a house with no shade.
"The keys are heavy foliage and late afternoon shade," Laband said. "The savings can be very significant for homeowners. Over the years I had read statements that shade trees reduce electricity consumption, so we wanted to put a dollar amount to it."
In an Auburn newsletter article by Charles Martin, Leband said his office conducted a yearlong study of 160 houses in the Auburn area to determine the annual energy savings provided by shade trees, primarily looking at the months from May to September. He analyzed power bills, calculated shade coverage and surveyed the homeowners about household makeup, electricity-usage habits, square footage, type of air conditioning, appliances, roofing, exterior material and other factors.
"We looked at the amount of shade in the early morning, early afternoon and late afternoon," Laband said. "If you have trees on the west side of your house, you will have a much lower power bill."
Using local power company rates for kilowatt hours per day, Laband said the 11.4 percent savings would equal $31 to $33 per month. The study, which categorized types of shade into light, moderate and heavy, also found that a house covered with 50 percent of light shade will save 10.3 percent.
Thermostat settings were important as well. "For each degree you lower your thermostat, you will save 3.3 percent on your power bill," he said. "We also found that children under age 12 are the major power consumers in the home. They watch television, play games and leave lights on."
Laband hopes the study will encourage real-estate developers not to cut down all the trees on new lots.