Solar energy is clean, abundant and renewable. In fact, more energy from the sun reaches the earth in one hour than is used by everyone in the world in one year (see References 1). Today's technology and improvements to building strategies allow you to maximize the sun's benefits. Increase the energy efficiency of your home, reduce your environmental impact and enjoy annual energy savings in home utility costs by implementing active or passive solar power systems.
Passive Solar Design
Homes built with passive solar design take advantage of the sun to provide heat and light. Orienting and designing your home with large, south-facing windows can effectively heat a home without additional heat sources. Wall and flooring materials heat up during the day and slowly release heat during the night. Glazed windows and appropriate window placement can regulate heat from the sun and allow for the maximum amount of natural light. Overhangs and ventilation help keep homes cooler during summer heat. (See References 3)
Photovoltaics convert sunlight directly into electricity. Roof-mounted solar panels face south, or panels on tracking devices follow the sun. Home PV systems may be off-grid or grid-tied. Off-grid systems are independent of other power sources and often charge batteries for use when the sun is not shining. Grid-tied systems connect to the existing utility grid and offset the cost of utility bills. PV technologies are becoming more affordable with increased demand, government incentives and new financing programs.
(See References 4 and 6)
Solar Water Heating
Solar hot water heating, or solar thermal systems, use the heat from the sun to heat water for home use. Such systems generally consist of a roof-mounted solar collector and a storage tank. Small tubes run through the collector, heat up and carry the fluid to a well-insulated collection tank. Solar thermal systems are also useful for heating swimming pools. (See References 5)
Outdoor Off-grid Applications
Small-scale off-grid solar electric systems are available for a variety of home applications, such as outdoor lighting. These small solar panels collect energy from the sun by day and store it in small batteries for use at night. (See References 2)
- National Renewable Energy Laboratory: Solar Energy Basics
- U.S. Department of Energy: Energy Savers: Outdoor Solar Lighting
- National Renewable Energy Laboratory: Passive Solar
- U.S. Department of Energy: Energy Savers: How Small Solar Electric Systems Work
- National Renewable Energy Laboratory: Solar Hot Water
- National Renewable Energy Laboratory; Solar Photovoltaic Financing: Residential Sector Deployment; Jason Coughlin and Karlynn Cory ; March 2009
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