2007 SATURDAY HOMES

The following are homes from the 2007 tour. Homes on the 2008 tour will be listed in July.

Home 1 - Owings, Maryland

Features: pv, waste-heat recovery, solar hot water, ground-source heat pump, efficient furnace/appliances, net metering, composting, rainwater reuse, electric vehicles, biodiesel car

With 60 PV panels on the roof, it’s hard to miss this home. The owners have installed a grid interactive 2.2 kW PV system providing power to the home, their transportation and for resale back to the electrical grid. It was one of 10 Maryland Million Solar Roof program systems installed in 1998 and was powered up on January 18, 1999. In addition to the PV system, the owners have a GFX greywater heat recovery system which reclaims about 55% of the heat from shower water. The 4’X10’ flat-plate solar hot water collector on the back side of the home is connected to a 60 gallon hot water tank in the basement and provides solar heated water. Their primary source of heating in winter and cooling in summer is a WaterFurnace Premier 2 two speed geothermal heat pump. The energy-efficient Whirlpool refrigerator won the grand prize for energy efficiency in a federally-sponsored contest. The Asko dishwasher and horizontal-tumble Frigidare washing machine are also very energy efficient. Compact fluorescent lightbulbs are used for lighting. The family vehicles include a 2002 Toyota RAV4 EV and a 2000 Ford Ranger Electric pickup truck (both are 100% pure battery electric vehicles), and a 2003 Volkswagen Jetta TDI diesel wagon that is fueled with B100 soy biodiesel. The owners have an average electricity bill of $165 per month which includes fueling their both of their electric vehicles.

Home 2 - Upper Marlboro, Maryland

Features:pv, solar water heating, geothermal heating/cooling

The homeowners are reducing dependency on fossil fuels while maintaining modern conveniences and have chosen to install a 2,880 Watt, array of solar panels manufactured by BP Solar. The panels are grid-tied and net metering runs the electric meter backwards when the panels provide more power than the family uses. The solar domestic water heating system, consisting of Thermomax evacuated tube collectors, provides 70% of the family’s domestic hot water requirements to minimize the use of the electric backup water heating element. The super-efficient ground source heat pump keeps the family warm in winter and cool in summer, for a fraction of the operating costs of a heat pump.

House 3 - Arlington, Virginia

Features: pv, solar water heating, solar oven, greenhouse

Energy is one of the areas of emphasis in Potomac Overlook Park. A program about energy, which includes a slide show and firsthand looks at solar cooking and solar (photovoltaic- PV) electricity, is presented to adults and children age 8 and older. The solar oven and PV unit are also occasionally set up for public demonstration and used in other programs as well. The Park manager's house, located on site, has a solar water heater which is clearly visible from the park road near the nature center and which is interpreted with a display plaque. A greenhouse, situated in the Park's educational gardens, is equipped with a variety of solar energy features which are useful in any kind of building construction. Finally, there is a small display about solar energy in the nature center. A handout about the role of the sun in life and for human energy production is available for Park visitors. The Park also recycles yard waste by composting it into fertile soil.

House 4 - SE, Washington DC

Features: solar hot water, pv, energy efficient windows, supertherm insulating paint, window quilt, mini-split heat pumps/ac, rainwater collection system

Solar hot water and PV, as well as a DC SunFrost with battery backup. Pellet stove insert in the fireplace and a TempCast masonry stove in the basement (among the more efficient and clean burning wood stoves) and a Rinnai tankless back-up hot water system. House has been a donor and recipient of reused building materials. Interior double-glazed argon-filled framed-in-place picture windows to retain historic casement windows while reducing heat gains and losses. Future plans include greywater and enlarged rainwater collection.

House 5 - Mt Rainier, Maryland

Features: solar thermal panel, solar clothes dryer, skylights, superinsulation, energy efficient appliances and lighting, low environmental impact building materials, electric pick-up truck

The home features a host of energy efficicent improvments including Solar Thermal panel; solar clothes dryer; tubular skylight; Sunfrost refrigerator; reel lawn mower; all fluorescent lighting, organic garden, Energy Star front loading clothes washer. Green Home Renovation in Progress featuring: “cool roof”, radiant barrier sheathing, R-38 insulation, sidewall insulation, building envelope sealing, Energy Star doors and windows, low VOC paints, caulks etc., FSC lumber, bamboo, cork flooring. E-85 pickup truck, whole house water filtration. Solar thermal panel is a flat plate collector which blows sun heated air into the house, a PV direct panel operates the fan; tubular skylight brings diffuse day-lighting into darkened interiors, with no heat gain; Sun Frost fridge operates at less than 1 Kilowatt per day; organic garden is approximately 400 sf, growing wheat and /or vegetables for home use, utilizing kitchen scraps, weeds etc. for compost; Green Home renovation is based on Arlington County, VA Green Home Choice specifications, and is about halfway completed; Renewable Energy credits with Native Energy, at $12/ton, our household carbon dioxide payload of < 18 tons/year (below average), Energy credits help put wind power into the energy market. Also, water use well below average.

Of note: without air conditioning, and lacking generous tree shading, this home maintains an average 75 degree temperature through the summer months, only in the hottest heat waves rising above 80 degrees; typical summer electric bill shows ~ 4 KWH per day. We’d like to reduce that even more.

House 6 - NW, Washington DC

Features: pv, retrofit, solar hot water, radiant floor heating, special windows, waste heat recovery

This 3000 sq. ft Adams Morgan-Kalorama Triangle townhouse was retrofit with a 3 kW solar electric PV and a 360 sq ft solar thermal array for air-space and water heating. Other green/energy efficient features of the home include: Heating- gypcrete radiant floor heating with adjustable heating zones; high-efficiency natural gas condensing furnace for solar backup, 2 high-efficiency wood burning fireplaces as secondary, occasional or emergency heating system, drawing combustion air from outside; programmable thermostats. Cooling- high-efficiency air conditioning unit (14 seer unit), ceiling fans. Air Quality- HEPA air filtration, timer switches, fans, humidification system with automatic sensor/humidistat used in winter months, heat recovery ventilation system, low-VOC paints, adhesives, floor finishes, toxin-free area rugs, mattresses, all new formaldehyde-free cabinets; Insulation- Low-E glass on windows and doors, double and triple glazing on windows, soy-based spray-in foam insulation walls, floors, attic, soy-based reflective/waterproof roof coating over copper roofing, EPS in floors below radiant tubing; Water conservation and reuse- Rainwater collection and reuse system for toilets and hose bibs, low-flow faucets, flapperless, dual-flush toilets, high-efficiency/low water-use washer/dishwasher, centrifuge for removing water from clothes, on-demand hot water, shower timer. Water filtration- showers/faucets filtered, solar water distillation for drinking water and rainwater reuse. Electricity/lighting- 18 Shell Powermax PV panels to supply ~3 kW of power that is net metered, battery backup/inverter, skylights for daylighting.

Building 7 (School) - NW, Washington DC

Features: constructed wetland, pv, green roof, passive solar strategies, recycled/renewable/regional materials, solar chimneys

This school has been awarded a Platinum level LEED rating for the Middle School by the U.S. Green Building Council. It is the first K-12 school in the United States to have a LEED Platinum rating and the first LEED Platinum building in the District of Columbia. A constructed wetland treats the School's wastewater on-site, and the water is re-used in the toilets and cooling tower. The roof includes a green roof, organic garden beds, and a photovoltaic array. Building orientation, passive and mechanically assisted ventilation, solar chimneys and other features reduce the need for supplemental energy for heating and cooling. Window placement, skylights and reflective panels maximize use of natural light in classrooms. These energy efficiency measures result in 60% less energy being used when compared with buildings of a similar size. Recycled, rapidly renewable, and regionally harvested materials are used throughout. Paints, carpets, and adhesives were selected for low emission of volatile organic compounds. Volunteer guides will be on hand to offer tours every half hour.

House 8 - NW, Washington DC

Features: pv, net metering, Gridpoint battery back system

This 1924 Chevy Chase home features a grid-tied 4080 watt photovoltaic system consisting of 24 170-watt BP Solar Panels mounted on the south-facing second story roof. A 7 kWhr Gridpoint battery backup system was also installed and is charged by the panels. The system will operate at peak efficiency when the electrical load in DC is at its greatest thereby reducing the demand on the grid. The system was installed by Standard Solar in Gaithersburg, Maryland.

House 9 - NW, Washington DC

Features: PV, net metering, passive solar, protective vegetation, solar hot water, efficient lights, daylighting, superinsulation

This 2800 sq. ft. home features both active and passive solar. The home was originally designed as a passive solar home with direct gain from sunlight shining through 250 sq. ft. of windows onto a 600 cu. ft. concrete slab covered with quarry tile for thermal storage. The home was designed to maximize natural convection and with a solar chimney for cooling. Awnings and vegetation protect the home from overheating in summer, and skylights provide daylighting. A closed-loop collector provides solar-heated domestic hot water. To increase the energy efficiency, the home is insulated with fiberglass and StyrofoamTM. Most of the lights are fluorescent, there is an airlock entry, and automatic (setback) thermostat to aid in decreasing the energy load. The low-flow toilet tank conserves water and the cistern collects rainwater to use for watering the garden. Recently, the homeowners, with assistance from a grant from the DC Energy Office, have installed a 3.99 kW, grid-tied photovoltaic system. The PV system consists of 21 Sanyo 190W PV modules fabricated with a thin single crystal silicon wafer surrounded by ultra-thin amorphous silicon layers (so-called HIT cells). This particular panel has the highest efficiency rating available in the market in the U.S. An SMA SunnyBoy 6000 DC-AC inverter converts the DC current to AC power and is scalable. These homeowners also take advantage of net metering and enjoy watching their meter run in reverse.

House 10 - NW, Washington DC

Features:Green roof

This green roof is on a garage and one of the first private residential green roof projects in Washington DC. The base is a thick waterproof rubber material covered with a 6 inch thick layer of 70 percent staylite (a pumice like roofing stone) and 30 percent peat moss. It is bordered by red tiles with tiles placed randomly on the surface for stepping.Growing on the roof is a sedum variety of plants that are heat and drought resistent. This type of roof requires little maintenance other then periodic watering and weeding.In addition, green roofs can reduce city heat radiation back in the atmosphere by 7 percent. It reduces runoff by absorbing 75 percent of the rainwater and saves on heating and cooling losses by 26 percent.

House 11 - NW, Washington DC

Features: pv, net metering, organinc gardening composting

The homeowners installed a “standard” solar photovoltaic (PV) system (using state-of-the-art, high-efficiency polysilicon panels). The system consists of 28 215-watt SunPower solar panels capable of producing 5,200 watts of DC power in full sunlight. The SunPower panels use back-contact cells on a black substrate to give the panels a completely black appearance, creating a uniform and attractive appearance with the existing roof (there are no visible solar cells or metal contacts). The system is “grid connected” and takes advantage of the District of Columbia’s net metering.
The solar array is connected to a Fat Spaniel monitoring system that constantly measures and displays the system performance. This information is presented in the form of daily graphs of voltage, current, and wattage produced by the system. The wattage is also accumulated so that the power produced from system start up is easily examined and electricity generated will be compared to electricity consumed. The system offsets the production of the greenhouse gas carbon dioxide and other air pollutants resulting from the burning of coal. The system saved 12,000 lbs of CO2, 65 lbs of SO2, and 34 lbs of NOx in it’s first year.

In addition to the solar panels, the homeowners also practice other environmentally friendly behaviors: organic gardening, composting, energy efficient appliances, and compact fluorescent light bulbs throughout the home, and they drive a hybrid car (Toyota Camry). The homeowners are implementing recommendations from a D.C.-sponsored energy audit.

House 12 - Silver Spring, Maryland

Features: pv, solar tube skylight, solar attic fan, energy efficient appliance, energy efficient lighs, rain barrales, water saving toilet, hybrid electric vehicle

The owners of this home installed a 3.06 KW grid-connected PV system as well as a 60-gallon solar hot water system with financial assistance from a grant and tax credit from the State of Maryland and Montgomery County. Most lightbulbs have been replaced by energy-saving compact fluorescents, all rooms except for bathrooms have ceiling fans decreasing the need for air-conditioning, and the dishwasher, washer, and dryer have all been replaced with ASKO-brand appliances, a Swedish brand which specializes in energy- and water-saving devices.

House 13 - Rockville, MD

Features: pv, solar tube skylight, solar attic fan, energy efficient appliance, energy efficient lighs, rain barrales, water saving toilet, hybrid electric vehicle

The owners of this 1400 square foot 1951 Cape Cod installed a 1 kW polycrystalline photovoltaic system on the roof. The grid-tied system includes 8 125-watt Kyocera panels and a Sun Tie inverter. The panels supply 40% of the home’s total electrical needs after efforts to increase the energy efficiency of the home, including efficient windows, compact fluorescent lights, Energy Star-qualified appliances, a solar attic fan, and solar tube skylight on the second floor. The house was recognized by the City of Rockville with an environmental excellence award. The cost of the system was defrayed with a grant from the Maryland Energy Administration.

House 14 - Rockville, MD

Features: solar heated water, pv, energy efficient lighting, electric lawn mower, solar oven

This handyman homeowner has installed 1000 watts of PV with panels from
Shell Solar, Matrix, and GE Solar as well as a closed loop propylene glycol Alternate Energy Technology (AET) solar water heating system. The PV is a 24 VDC stand alone system, using 12 deep cycle golf cart batteries as storage, and a 1500 watt Xantrex inverter to convert power to AC. The PV system charges the homeowner’s battery powered electric lawnmower, refrigerator, solar hot water pumps, television, and DIRECTV system. The solar water heating system consists of two AE single glazed panels with black absorber surfaces. A double walled heat exchanger transfers the heat from the propylene glycol to the potable water. Two pumps powered by the PV system circulate the liquids. The solar system preheats the water in a separate water tank which supplies the primary hot water heater tank with preheated hot water, a closed loop preheat system. The sun supplies about 90% of the domestic hot water needs in the summer and 50% in the winter. Most of the lights in the home are compact fluorescent. A solar oven cooks food in sunny weather without heating up the home or using fossil fuels.

House 15 - Poolesville, Maryland

Features: pv, solar-powered attic fan

The homeowners are reducing dependency on fossil fuels while maintaining modern conveniences and have chosen to install a 2,084 Watt array of solar panels manufactured by BP Solar. The panels are grid-tied and net metering runs the electric meter backwards when the panels provide more power than the family uses.

House 16 - Gaithersburg, MD

Features: pv, solar hot water

This Cape Cod house has a large 2.7 kW system with 18 panels on the front roof and solar hot water heat. One rain garden is finished and others are in progress and planting many native plants.

Building 17 (farm) - Germantown, Maryland

Features: UMD 2005 Solar Home entry in the Solar Decathalon

This farm is home to the University of Maryland’s 2005 Solar Decathlon entry: an 800-square-foot one-bedroom all-solar house.The Solar Decathlon is an international competition, sponsored by the U.S. Department of Energy, in which interdisciplinary university teams compete todesign, build, and operate the most appealing, energy-efficient, sustainably-conceived, totally solar-powered house. This house won the BP “Innovation Award” and the “People’s Choice Award” in the competition with 17 other teams in October 2005. The house features 51 175-W photovoltaic panels installed on a curved roof, evacuated-tube solar water heating, a hot-water radiant floor, state-of-the-art appliances, triple-pane windows, cedar siding, recycled glass tile, recycled rubber flooring, and bamboo flooring and cabinetry. When completed, the house will be grid-tied; it was designed to operate off-grid, including providing power to an electric car. Because the house is under construction, entry is not permitted. Visitors will be able to enjoy views of the exterior through the windows. Members of the Maryland Solar Decathlon team will be on hand to discuss and interpret the house, and to share photos, drawings, and material samples as well as their vision for victory in the upcoming 2007 Solar Decathlon.

House 18 (two cottages) - Germantown, Maryland

Features: pv, solar hot water, energy efficient windows, insulating window shades, geothermal heating and cooling, passive solar heaing, composite siding

These two staff cottages are the initial phase of a ministry center, a 206 acre church retreat farm in east Germantown. This project has arisen out of a spiritual calling to explore ways of living more simply, justly, and in harmony with the earth. Each cottage is 1250 square feet, and is designed to provide a gracious and energy-efficient home for a couple or a small family. The cottages have accomplished this in different ways; between them they include the following features: passive solar heating and cooling, well-insulated walls and roof (structural insulated panels/blown cellulose), top energy-efficient windows and appliances, insulating window shades, living roof, FSC-certified framing lumber, geothermal heating and cooling, grid-tied and grid-independent photovoltaic panels, solar hot water, masonry heater, oak and cherry trim from trees on the land, earth plaster and milk paint wall finishes, stained concrete slab floors, bamboo floors, fiber-cement composite siding and trim, roof water collection, and landscaping with native plants. Integration of these features and simple living practices have resulted in these cottages being nearly zero energy homes and a delight to live in.

House 19 - Germantown, Maryland

Features: pv, solar hot water, energy-efficient lights and appliances, set-back thermostat, rainwater reuse, composting

This 2700 sq. ft. pseudo-Victorian home, built in 1983, sports 1.5 kW of BP Solar MST-43 panels with an integrated hot water system. The inverter is a Xantrex SunTie XR1500, and the system is net metered. Funding assistance was received through the Maryland Residential Solar Rebate Program. Compact fluorescent bulbs, an Energy Star-compliant refrigerator and dishwasher, and a programmable thermostat augment the energy savings. Rainwater from the roof is collected in 4 barrels to satisfy the garden's water needs and they use indoor and outdoor
compost bins. Children are welcome!

House 20 - Lovettsville, Virginia

Features: Grid-tied pv with battery backup, solar hot water system, standalone pv powering an outbuilding, hybrid vehicle, solar cooker, efficient appliances

Stroll past the homeowner’s vineyard to see one of the few net-metered PV systems in Northern Virginia. Most of the region’s electricity comes from coal (mountain-top mined) and nuclear sources, but not at this house! The 2.1 kW solar array supplies approximately one-third of the home’s power usage. (Heating is mainly by woodstove). The PV system features an Outback 3648 inverter with battery backup, coupled with 12 x 175 w Shell Powermax modules ground-mounted on a wind-resistant support structure. Efficiency measures include a front-loading washer, energy-saving refrigerator, fluorescent lighting, hybrid vehicle, and switches to turn off phantom loads. The house also demonstrates proper solar orientation and use of deciduous tree plantings to manage solar gains. The winery/garage sports standalone PV panels. Weather permitting, visitors will be able to enjoy solar-baked cookies while they watch the electric meter spin backwards—just two of the simple pleasures of the solar enthusiast. New for 2007 - Hot water from the sun! Check out the solar hot water system built from a Heliodyne Inc. kit.

House 21 - Lovettsville, Virginia

Features: passive solar, active solar, efficient appliances, super insulation (structural insulated panels), geothermal heating and cooling and environmentally friendly construction materials.

This village of eco-friendly homes are clustered to preserve more of the 180-acre site. The homes feature energy-efficient designs using passive solar, geothermal heating and cooling and many green building materials. With convenient commuter rail access, the organically managed site emphasizes a kid-friendly pedestrian infrastructure that is integrated with nature.

House 22 - Purcellville, Virginia

Features: passive solar, active solar, efficient appliances, super insulation (structural insulated panels), geothermal heating and cooling and environmentally friendly construction materials.

This house, which was once featured on the National Mall and in President Bush’s National Energy Policy, is nearly a true Zero Energy - Grid-Tied Solar House and is offered for sale as the owners are moving to Georgia. It features 4.0 kilowatts of solar PV from a Uni-Solar Standing Seam Roof and an additional 2.0 kilowatts of BP Solar PV modules on the garage. In addition, the house features 2.0 kW (equivalent) hot water panels supplied by Solargenix which, combined with a heat exchanger for hot water off the 5.0 ton Geothermal heat pump system, reduces hot water energy use by nearly 90% to just 1 kilowatthour per day. Energy-efficient appliances, lighting and passive solar design coupled with geothermal heating and cooling means that this house uses less than 10% of the energy a typical 3800 square foot, four bedroom, three and a half bathroom house would require. Energy use in the last 12 months has averaged just 7.7 kWHs per day (<$1.00). A 1600 Amp-Hour battery bank provides more than 10 kWHs of stored energy daily for emergency operation.

The house, situated on 5 acres of rolling farmland, next door to a vineyard, in the beautiful “Land between the Hills” region of western Loudoun County, offers affordable and graceful country living as well as great opportunities for a bed and breakfast. The owners are offering a SPECIAL DISCOUNT on this house for solar tour takers.

House 23 - Fairfax, Virginia

Features: structural insulated panels, insulated concrete forms, timberframe, radiant floor heat, low flow toilets, solar-ready construction, shading porches, Energy Star appliances, recycled construction materials

Craftsman style home. 1450 square ft plus unfinished partial basement. Elderly-friendly first floor. Accessible to public transportation, bicycle to parks, shopping. Extensive re-use of construction materials. (Dog-friendly features, too.)