AUBURN – Shade trees keep our houses cooler, but just how much do they reduce electricity bills? An Auburn University researcher is seeking to answer that question.
Professor David Laband in the School of Forestry and Wildlife Sciences is conducting a study of houses in the Auburn area to determine the annual energy savings provided by shade trees.
“Over the years I have read statements that shade trees provide ecosystem services like reducing electricity consumption, ” Laband said. “The claims have never been measured very well, though, so we want to put a dollar amount on the impact of shade trees.”
Laband recently received a $116,000 matching grant from the USDA Forest Service’s Urban and Community Forestry Program, based on the recommendation of the National Urban and Community Forestry Advisory Council. Auburn University’s School of Forestry and Wildlife Sciences is providing the matching $116,000 toward the overall $238,000 project.
Laband and a postdoctoral fellow will be distributing questionnaires to 1,000 households in the Auburn area and hope to get 250 to 350 participants for the study. They are selecting houses with varying amounts of shade coverage and are asking participants to submit information about power usage, square footage, type of air conditioning, appliances, roofing, exterior material and other factors. Participants will follow-up with shorter, monthly surveys for one year about their energy costs.
“We are gathering real data from real living conditions,” Laband said. “This will make the analysis very complex, but it will be a very good analysis, rich with details. Each household will have its own lifestyle and characteristics that will be invaluable to the study.”
The researchers will compare energy usages and costs among the households and will factor in the amount of shade tree coverage for each one. They also will look at the amount of shade provided during various parts of the day and at different times of the year.
“Everyone knows that you’re cooler in the shade,” he said. “Many older houses have large trees around them because the owners did not rely as much on air conditioning then. Houses today often do not have shade trees because it’s easy to run the air conditioner. We want to show them how much they can save when trees are used in yards.”
He says very little research has been conducted on the subject. “It is such a well-known concept, but we have found only one previous large-scale study,” Laband said, “and it was in the 1980s and only had about 130 homes in the project.”
He adds that a future AU project might include building two identical houses in which the amounts of shade and other conditions could be tightly controlled and measured with instrumentation.
“That would be a good follow-up to our current survey,” he said, “and it would give precise readings, but it would not factor in residents’ lifestyles, which is why we started with the survey of actual households.”
Laband, who earned his Ph.D. in economics from Virginia Tech in 1981, conducts research and teaches on topics related to economics and policy, with a focus on natural resources. He joined the Auburn University faculty in 1994 and the School of Forestry and Wildlife Sciences in 2000, where he is a member of the Center for Forest Sustainability and the Forest Policy Center.
(Contributed by Charles Martin.)