All About Solar
How to Take Advantage of Free Energy
Solar energy occurs when the sun’s rays reach the earth. Even though the majority of energy radiated by the sun is absorbed in space, the amount of energy the earth receives daily could support our nation’s energy needs for one and a half years, according to the Secondary Energy Infobook. So, the question is: How do we best capture the sun’s energy in our homes and turn it into a reliable source for heat and light?
More than 10,000 homes in the United States run on solar energy and many more “green” homes are currently on the market. These homes operate on passive solar energy, active solar energy, photovoltaic solar energy, or a hybrid derived from these renewable resources. Active solar homes require the use of some mechanical equipment whereas passive homes do not. Instead, these homes rely on strategic window positioning. In North America, the sun shines from the South so windows are built facing in the same direction. Few, if any, windows should be built on the North side.
Passive Solar Homes
Heating and Cooling
Heat is administered when the sun’s rays shine through the strategically positioned windows, and are absorbed by walls and floors. The passive design integrates window, wall, and floor areas to collect, store, and distribute energy in the form of heat. Opening and closing doors and windows can regulate home temperature. Heavy window treatments can be used at night to maintain the indoor heat that was generated during the day. It’s helpful, but not necessary, to use fans to circulate the air throughout the home.
Passive heating systems work because heavy interior materials like stone, concrete, and adobe, are used to trap heat and later radiate heat.
Cooling your home is almost as simple as turning on an air conditioner - except you will save electricity and significant costs. Tinting or glazing windows and skylights with various coatings can significantly affect heat loss and gain. This works well in conjunction with other cooling methods. Light-colored roofs and walls reflect the sun’s rays back into the atmosphere. Shading fixtures such as awnings and porches are very helpful when positioned by south-facing windows. Exterior plants, trees, and vegetation, also help to block the sun’s rays from entering through the windows by creating shade.
Passive Daylighting
Natural light created “passively” has shown to improve one’s general health and wellbeing. Exposure to daylight increases the body’s production of Vitamin D, which boosts a strong immune system, among other benefits. When building a passive solar home, it’s important to keep “the daylight zone,” in mind so that you can determine which spaces in your home will benefit from exposed sunrays.
Active Solar Homes
Heating and Cooling
According to the U.S. Department of Energy, passive solar systems should be considered before integrating an active solar system with your home’s design. This is because passive systems require the least amount of energy. Solar homes require the use of mechanical equipment - such as pumps and fans - to increase the amount of heat that is captured and stored. Unlike passive systems, which don’t require external energy, active systems rely on external sources to heat the home when solar energy is not sufficient.
Active systems use solar collectors to create heat from the sunlight they absorb. Heat is created when air or liquid passes through solar collectors that warm it and then disperse. Collectors are generally placed in areas that generate the most sunlight such as the south side of roofs.
It’s wise to utilize the extra heat generated on bright, sunny days by storing it for use on cloudy days. The heat can be stored in a large tank filled with liquid or in a rock bin beneath the home.
Solar Water Heating
According to MSN.com, water heating is usually the third largest home energy expense and generally accounts for more than 13% of your utility bill each month. A solar water heater can significantly reduce costs over the long-term and generally lasts between 15 and 20 years longer than traditional water heaters.
A solar water heater works similarly to active solar heating in that collectors are placed in direct sunlight to make heat. When the collectors are adequately hot, the thermostat starts a pump, which circulates “heat transfer fluid,” through the collectors for heating. This fluid travels to a water storage tank and heats the water.
Photovoltaic Homes
Energy
Photovoltaic energy occurs when light is converted into electricity with the use of photovoltaic cells or solar cells. The cells make electricity, for as long as light shines on them – similar to a solar-powered calculator. Little maintenance is required, operation is silent, and the energy is clean and safe. In fact, it’s the cleanest and safest method of power generation available.
Photovoltaic systems use solar electric panels, which are usually installed on roofs. Also used are photovoltaic modules, which are normally rectangular, and come in a range of sizes up to 4 ft wide by 8 ft long.
If the need for electricity is ever higher than the photovoltaic energy system can provide, typical utility energy can be used. However, if the photovoltaic system makes more energy then is necessary, utility companies will generally provide a credit for the price equivalent.
Purchasing environmentally friendly homes is easy, as builders are taking notice of the increased demand. More “green” homes are being built all across the United States and beyond. Besides helping Mother Nature stay healthy, you will find that there are many benefits of living in a “green” home, which include tax credits, high resale value, and general health and wellbeing. Taking advantage of the sun’s energy is an important step towards preserving the earth’s integrity.
Sources
http://www.need.org/needpdf/infobook_activities/SecInfo/SolarS.pdf
http://www.sei.ie/index.asp?locID=264&docID=-1
http://www.energyrefuge.com/archives/solar_power_homes.htm
http://www.eia.doe.gov/kids/energyfacts/sources/renewable/solar.html
http://www.newenergy.org/sesci/publications/pamphlets/passive.html
http://oikos.com/library/energy_outlet/passive_solar.html
http://www.eere.energy.gov/buildings/info/design/integratedbuilding/passivecooling.html
http://www.toolbase.org/Technology-Inventory/Electrical-Electronics/pv-systems
http://www.msn.com
http://smartenergyliving.org/cm/Solar/Passive%20Solar%20Design.html
http://hubpages.com/hub/Natural_Daylighting_for_Health_and_Energy_Efficiency
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