WEB EXCLUSIVE

When my husband Mitch Ross and I attended the 2002 Solar Decathlon, we didn't expect to have a life changing experience. But after spending two afternoons at the event, we were inspired to design and build an energy-efficient solar house and sell our "dream home" in northern Virginia.

Three years of research later, we moved into our rural Cedar County, Mo., home, which uses solar energy four ways: to heat interior space on cold sunny days, to heat water, to provide natural lighting and to generate electricity that helps power the house year-round.

Our home has been a popular southwest Missouri stop on the American Solar Energy Society's National Solar Tour for the last three years. Our Home Energy Rating System score of 38 means our house is a near-zero energy home. It has won accolades, including the 2008 gold National Energy Value Housing award and the 2008 EVHA People's Choice award for its energy efficiency.

Building our solar-drenched home wasn't easy, though. We at first assumed we could build the home we envisioned near northern Virginia, where we were living at the time. With the housing boom in full swing, though, we could not find a building designer or builder who could - or was willing to learn how to - build the non-traditional home in our minds' eye.

Our search expanded to include a large portion of the mid-Atlantic and Southeast. We eventually settled on Missouri after finding the perfect spot for a passive solar home and talented professionals to help us build it, Orlo Stitt of Arkansas' Stitt Energy Systems Inc. and "master builder" Ted Anderson of Anderson Construction LLC in Stockton, Mo. Lots of designing and decisions later, we moved into our solar dream home in 2006 and started enjoying the benefits of solar energy.

The house's passive solar design enables the sun to heat interior space on cold, sunny winter days. To maximize solar gain (heat) when the sun moves low in the southern sky, the house is oriented on solar south, with most of the windows on the south side. Calculated window overhangs allow sun rays to shine 11 feet into the rooms on the south side. The sun alone easily heats interior temperatures into the mid-70s, no matter how cold it is outdoors. The house's air-tight envelope enables it to hold the solar heat. In contrast, when the sun moves high in the northern sky during summer, the overhangs block the sun from hitting the window glass, so it does not heat the interior. I like to tell tour-goers that passive solar design has no moving parts to break, requires no permits and adds anywhere from zero to just 3 percent to the cost of building a house.

Water heating accounts for 14-25 percent of the energy consumed by a home, according to the Department of Energy. But thanks to our solar water-heating system, if the sun is shining, no matter how cold the outdoor temperature, our water is heated using no electricity. Powered by a small photovoltaic (PV) panel, recreational vehicle-grade antifreeze circulates through a black 3-foot by 8-foot (about 1-meter by 2.5-meter) thermal panel on the roof and then is sent through a heat exchanger to heat the water in the storage tank. The well-insulated 80-gallon Rheem tank holds the heat for about two cloudy days. The tank came from the factory with the internal thermostat set at 160°F (71°C), scalding temperature. After much experimentation, Mitch turned it down to about 120°F (49°C). If extended cloudy days cause the water temperature to drop below 120°F (49°C), the electric backup system in the tank is set to run about two hours a day to heat our water. Most of the time, though, that is not necessary. The system is essentially maintenance-free and greatly reduces a home's demand for electricity. Plus, a 30 percent federal tax credit for the purchase price makes it affordable.

Lighting is approximately 20 percent of the average household's energy bill, according to Energy Star. In our home, we rely on natural lighting on sunny and even overcast days, which means we turn on lights infrequently during the day. The rooms we use most during daytime are designed to capitalize on passive solar benefits, strategically positioned on the south side with most of the windows on the south. To augment natural lighting through the windows, our house also has an electric Velux skylight in the kitchen's cathedral ceiling and a Velux sun tunnel in the windowless master bathroom. Sunlight shines through the sun tunnel's clear dome on the roof, down through a 16 inch wide flexible foil tunnel. The reflective foil lining intensifies the sunlight and lights the interior room with bright natural light.

We also use solar energy to help power our 3,718-square-foot all-electric house. Our 3-kilowatt PV system includes 18 Sharp PV panels on our roof, a Solaris 3500 XP smart inverter and 12 Jell-Cell batteries by Alphacell. When the system generates more electricity than our house needs at any moment, the smart inverter sends the excess to the grid for others to use. In 13 of 27 months for which data are available, our system generated more than half of the electricity consumed by our house each month. When grid power fails, the system or the backup batteries power most of our lights and outlets, the refrigerator and freezer, our well pump, the microwave oven and our fireplace blower fan. In other words, when grid power fails, we can still live comfortably. The longest grid power outage we experienced to date was four days, four cloudy days. Still, we used electricity from our backup batteries frugally and lived comfortably.

The PV system is the most expensive solar energy feature in the house. The payback period for a PV system depends on several variables: net metering, system cost, annual energy production, electric rates, annual electric rate increases, federal and state tax credits and utility incentives. Missouri's Proposition C, which passed in 2008, provides additional financial benefits. Considering all of these factors, a system of our size installed in Missouri in 2009 should pay for itself in nine to 10 years. For more information on calculating payback, visit ongrid.net/papers/SolarTodayPayback2006.pdf (PDF download).

From January 2007 to December 2009, our monthly electric bill averaged $63, which includes the $20 monthly service availability charge. This includes powering two active home offices, an electric farm cart and the well pump, as well as heating a passive solar guinea house during frigid weather. We burn a little over two cords of firewood each winter and use no propane and no generator.

We recommend PV systems to homeowners who have done everything possible to reduce their home's electric load, who have good, clear solar access and who are willing to invest because they believe it is the responsible thing to do. We view our investment as an excellent down payment on national energy security.

Small Steps Can Make A Big Difference

The reason our PV system can generate more than half of the electricity we consume most months is that we work continuously to reduce our electric load. We invested in an air-tight envelope, passive solar design, the solar water heater, an efficient HVAC system, a very efficient wood-burning Vermont Castings fireplace, Energy Star-rated appliances and electronics, and compact florescent and LED light bulbs. We aggressively reduced our phantom load by plugging electronics into power strips on timers; we also turn off lights when not in use.

People get excited about installing a PV system and generating their own electricity. However, many who live in existing homes can reap better returns on investment by tackling some smaller projects first, such as: gradually replacing all incandescent light bulbs (including night lights) with compact florescent and LED bulbs - starting with those left on most of the time; upgrading insulation, windows and doors; replacing old appliances with Energy Star-rated ones; buying only Energy Star-rated electronics; reducing phantom load by plugging electronic components into power strips that you can turn off when not in use and developing the habit of turning off unneeded lights. These investments, including installing a PV system, are inflation-proof, start saving money immediately and continue to do so indefinitely. As the price of electricity increases, the return on investment also increases. In some parts of the country, according to real-estate appraiser studies, the value of a home can increase $20 for every $1 saved in energy-efficiency improvements.

The solar and energy-efficiency technologies in our home not only reduce our energy consumption and costs, they also greatly reduce the amount of pollutants our home releases into the atmosphere. The emissions report of our home energy audit estimates our house prevents 22.7 tons of carbon dioxide from entering the atmosphere each year. That is 59.2 percent less carbon dioxide than a similar "all-electric reference home" that meets the 2004 International Energy Conservation Code. The report also estimates our house emits 59.2 percent less sulfur dioxide and 59.2 percent less nitrogen oxide per year.

Why not go solar now?

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About the Author: After attending the 2002 Solar Decathlon, Cheryl Y. Marcum, M.Ed., began to re-orient her professional consulting, research and writing skills from strategic human resource management for the RAND Corporation and U.S. Navy commands to designing and building an award-winning, energy-efficient solar home. She and her husband, retired Army Col. Mitch Ross, tirelessly champion the extraordinary benefits of solar energy paired with energy efficiency. Contact her at go.solar.now @ gmail. com.

Take a virtual tour of the couple's home at http://cu.motherearthnews.com/pages/gallery.php?gallery=296374.