Solar-Friendly Foliage

From on October 31, 2007 in CalFinder News

Solar and TreesWe all know that planting trees are good for the environment. They release clean oxygen and absorb carbon monoxide, which has increased in the atmosphere due to fossil fuel burning. Around the home, plants and trees can also help conserve energy by reducing heating and cooling costs. In fact, landscaping and foliage are critical elements of passive solar home design. Working in conjunction with the home’s orientation and window designs, the right foliage can shield your home from high winds, provide cool summer shade, reduce sunlight glare, and during the colder months, maximize sunlight absorption.

Solar homes in the Northern Hemisphere generally use south-facing glass while those in the Southern Hemisphere use north-facing glass to get the most out of available sunlight and natural heating. This can result in excessive heating and brightness during the summer. One device-free solution to this dilemma is to plant deciduous trees that lose their leaves seasonally.

The majority of the U.S. has a temperate weather climate. Homeowners will want to plant high, leafy trees along the south side of the home for increased summer-time shade. In the West, shorter trees work for afternoon sun angles that fall closer to the ground. In cold climates, it may be a good idea to avoid planting any trees along the south side of the home. Even though deciduous trees shed their leaves during the winter, thick branches can still block winter sun.

In cooler, windy regions, such as the northern U.S., homeowners can select Evergreens and shrubs that never shed and have the substance to block heavy winds. Homeowners living in hot, arid regions in the southwest will want to cool hot roofs, walls, and windows. Shrubs and groundcover help to cool the ground around the home, ultimately cooling the air before it reaches walls and windows. Rows of hedges or bushes can shade patios, driveways, and sidewalks. Climbing vines can also shade patios and walls, thus cooling the interior of the home.

Deciduous trees include maples, oaks, elms, aspens, and birches. As a slow growing tree, it lives long and has deeper roots and sturdier branches. A young tree will shade your windows and grow tall enough to shade your roof within 5 years. Shading provided by deciduous trees and other solar friendly foliage can increase the energy efficiency in an air-conditioned or heated home by up to 10 percent. For more information on passive and active solar energy techiques, visit CalFinder’s solar library.

U.S. Department of Energy: Your Home Landscaping