Most of our basic needs in life can be provided for by a Sustainable Solar Home through how it interacts with the sun. Sustainability refers to how readily resources that we use can be replenished, or "renewed". For example, electricity generated by solar panels is completely sustainable and renewable because additional electricity can be easily and cleanly produced the same way. This is in contrast to electricity generated by burning fossil fuels, as is the practice of most utility companies. These fossil fuels are a limited commodity which cannot be replaced- once they are burned they are gone forever. Furthermore, when they are burned they pollute the environment. Therefore, fossil fuels are not a renewable resource, and so burning them to produce energy is not a sustainable practice. Sustainability also refers to how much energy it takes to keep a home functioning and habitable. An SSH makes a switch from being dependent on external sources for power, such as utility companies, to being independent and able to generate its own energy from the sun. The bottom line is this, the greater the energy we can harvest from the sun, the lesser need we will have for large electrical power use, grid hookup, or large scale fuel consumption, and the less we will have to pay for such resources over time. Further, when the financial requirements of our life are lowered, then our corresponding stress about, and time invested in, producing financial resources to live on is greatly reduced. How great is that?...
People getting their needs met by accessing the energy of the southern sun is no new strategy. Above is the southern oriented dwellings of the Anasazi peoples of the southwest.
10 Ways an SSH uses the Sun instead of Utility Companies:
1. Interior heating. A Sustainable Solar Home is a home built of, and filled with, dense thermal mass materials. These include things like concrete, concrete blocks, compressed earth, Adobe block, mud, tile, stone and brick. This mass is all surrounded by rigid insulation on the exterior of the home. With the south side of an SSH being constructed entirely of glass, angled at 30 degrees, the sun will flood the interior. An SSH is a "passive" solar structure, with the interior thermal mass continually absorbing, capturing and releasing thermal (heating) energy inside the home, minimizing temperature swings throughout the day. This all happens without the need for any sort of energy-guzzling furnace. You will notice that there are no south facing overhangs. We choose rather to control sunlight with interior shades that can be easily adjusted. This is because we want to be able to gather a maximum amount of solar energy all year long, with the excess simply being vented out. We will, however, use covered porches on the east and west sides of the house to eliminate the extreme heat gain that can happen if these walls were to be un-shaded.Furthermore, the “radiant-style” heating and cooling which happens throughout the entire SSH provides a far more comfortable environment than air (as well as dust and allergens) being blown around by an HVAC unit, or heating available through other forms of space heating. The end result is that the interior temperature in an SSH will hover between 65-75 degrees with no fuel or electricity required. With the aid of passive ventilation and shading, the interior temperature can be further controlled for comfort. Electricity is neither used to produce heat, nor to move heat around within a Sustainable Solar Home. Unlike an SSH, mainstream construction methods produce homes with little thermal mass inside, and therefore, they store heat energy only in the air within the home. Because of this, their inside temperature quickly conforms to exterior temperatures and is why they require energy burning furnaces and air-conditioners to help maintain a comfortable interior temperature. Where an SSH can freely ventilate with clean and fresh outside air (using earthtubes and windows) and not lose its heat energy, conventional construction is limited to re-heating or re-cooling stale, and possibly contaminated, indoor air.
2. Water heating. We utilize two batch-style 40 gallon solar water tanks on the roof to heat 80 gallons of water on a daily basis. These tanks of water will sit in the sun and soak up solar energy, heating all of our domestic water supply. One 40 gallon tank will flow to a back-up propane powered on-demand hot water heater which will service the entire house. This water heater will add heat to the water only when the sun is not out. This will greatly reduce the amount of power used for water heating. The second tank will work as a true stand-alone batch water heater. This tank will drain solar heated water directly into the master bathtub by gravity.
3. Electricity generation through solar panels (Photovoltaics or PV). First of all, using solar energy in all of the ways listed here allows us to install a much smaller, and therefore less expensive, PV system than your average energy intensive home would need. We will use twelve solar panels installedacross the length of the apex of the roof, providing roughly 2.76 kW of power on a daily basis when the sun is out. Excess power can either be stored in a battery bank (off-grid application), or at the PUD using a net-meter, as we have. With a properly sized system there is always power available, even when the sun is not shining. This system will provide for all of the electrical needs of the home. In this solar powered house, all of the lighting, electronics and appliances used are powered by the sun.
4. Convection powered passive ventilation. As interior air temperature increases it will rise to the apex of the ceiling. If the interior begins to over heat, ceiling vent doors can be opened to expose a total of seven, 10” diameter ventilation ducts. These vents allow ceiling level hot air to escape straight up and out the top of the roof. This will create a vacuum that will pull fresh cool air into the house through either the windows and/or the earthtubes. This is especially effective when done at night during the summer when cool night air can flow through the house cooling the thermal mass, which will then keep the house cooler the following day. Much of the year occupants in an SSH can enjoy a soft comfortable breeze moving through the home.
5. Room lighting. The south side glass of a Sustainable Solar Home allows massive amounts of sunlight deep into an SSH during the daytime, especially during winter months. At winter solstice solar energy travels three-quarters of the way to the rear of the house. The clerestory windows provide additional sunlight farther back to the north side of the interior. A sun-tube provides light to the laundry area where no window lighting is available. Because of this, there will be no need for electrical lighting during the day in this Sustainable Solar Home. Also during the day, solar lights can be placed in the sun under the sloped glass to charge. These can then be used at night to light the interior, further reducing the need for electrical lighting. A combination of low-watt CFL and LED lighting will be used for all electrical lighting.
6. Water harvesting through snow melt. Solar energy from sunlight will help to melt any snow thatbuilds up on the south side of the roof. Without exposure to the sun, snow in the winter tends to evaporate over time. Being able to capture this water will allow us to harvest rainwater when the sun is out during cold and snowy winter months.
7. Greenhouse garden growth. Interior planter beds span the entire 80' length of the south wall. Sunlight coming in through the slanted south-sideglass will allow us to grow all sorts of organic plants year-round in these planter beds. Greenhouse plants, more than 200 square feet in all, will provide ambiance, food production, beautiful colors and sweet smelling aromas, all while scrubbing the interior air and helping to re-oxygenate it. In home food production specifically eliminates the embedded energy and greenhouse gas production involved with growing, shipping, wholesaling and retailing food- including foods like bannanas, citrus, vegetables, berries, etc. This, again, lowers the carbon output, or footprint, of our life. Lastly, these plants will help to produce healthy humidity levels within the home.
8. Solar oven food cooking. A solar oven will be built against a south side panel ofglass in the kitchen which will recieve direct solar energy on sunny days. This oven will be able to sustain temperatures up to 300+ degrees on a sunny day, and will allow us to use less propane for kitchen range cooking and less electricity for microwave cooking. There are, by the way, many solar cookbooks on the market today designed to help you get the most out of your solar oven.
9. Solar clothes drying. With its large sun-lit interior, clothes drying is easy to do in a Sustainable Solar Home, regardless of the season of the year. A standard propane clothes dryer will be available for use as well.
10. SSH owner health. We humans need a certain amount of sunlight (full spectrum UV light) in order to maintain good mental and emotional health, as well as good physical health. A Sustainable Solar Home structure allows occupants to enjoy and interact with the sun, by way of its large sun-lit interior, whenever they would like. Furthermore, a full south wall of glass, especially one that is angled, truly gives a sense of nature coming right into the home. Sitting in the sun, watching nature and gardening are all common pastimes in an SSH.