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Made in the shade: Trees save energy costs
A recent study shows the average Arizona Public Service customer can save on electricity by planting more trees around their home.
According to the study "Phoenix Green," a home with three mature trees on the sunstruck side could save 642 kilowatt hours of electricity, said David Berry, report author and chief of policy analysis for Western Resource Advocates.
"If you assume 10 cents per kilowatt hour, it will save 5 percent or $64 in electricity per year. But the savings is likely to be more when you consider the extra energy consumed with air conditioning in the summer."
Dave Faires, urban forestry supervisor for Yuma Parks & Recreation, agrees.
He specified that a well-placed, correct species of tree can save 10 to 15 percent on your energy bill, "no doubt about it." And, trees add comfort to outdoor living space.
"I would think you could save hundreds of dollars a year, certainly more than what the trees would cost you."
But Faires also noted a word of caution. He says the wrong tree in the wrong place could cost a home owner thousands of dollars in property damage. A ficus tree is an aggressive plant that grows very fast and large. Planted close to the home, it can invade a sewer system, crack a home's foundation, break through sidewalks or driveways and clog gutters by dropping leaves on roofs.
The preferred strategy is to plant deciduous trees, which lose their leaves in winter but when in bloom they can keep a home cool. There is no perfect tree, but some are much better than others, Faires said.
"We're not planting ficus in the city but I'd plant one in a park, a golf course or anywhere that's not next to concrete or a physical structure. The best situation around a home is planting cottonwoods, ash, pecan or mulberry trees."
Other good tree selections are the palo verde, elm, and mulberry, like those that have been planted in Riverside Park shading the cottage just below the Yuma Territorial Prison as well as royal poinciana and Texas Ebony in historic downtown Yuma.
If a homeowner plants the right tree in the right place it can only add value to a home, Faires stressed.
"The problem in Yuma is we have extreme temperatures and a lot of concrete that doesn't occur in nature, so trees are a way to combat the 'heat island' effect (concrete radiating heat back to the air). "
What Faires also does to relieve the heat is plant trees around parking lots. But, because the heat is so intense in Yuma, it can sometimes be difficult to get them established. But the Yuma Civic Center is a good example of ficus trees that have thrived without damaging infrastructure because there is ample room for growth.
Western Resources is a nonprofit organization based in Colorado that focuses on environmental issues but also examines energy efficiency, public land and water uses. Their study, Phoenix Green: Designing a Community Tree Planting Program for Phoenix was completed in November. It had two purposes: estimate energy savings from planting trees and identify how to set up an urban tree planting program, Berry said.
"What we're proposing is to plant 10,000 trees each year in Phoenix over 10 years. That could save 14,000 megawatt hours."
William Roller can be reached at email@example.com or 539-6858.