| Natural power from the sun has been with us for | | | | communities. |
| thousands of years. The earliest civilizations relied on it | | | | Passive solar power can be readily applied by new |
| as a sole means of light and heating. Today the world | | | | home builders, or renovators, to increase the amount |
| has the technology to harness the sun's rays and | | | | of available, natural lighting to a building by inserting |
| transform them into solar energy that can either be | | | | large windows in walls that face the sun. Added glass |
| stored or put to immediate use. Furthermore, sunlight is | | | | areas will allow more natural light to flood the building, |
| readily available and delivers enough energy per hour | | | | and can be designed to warm the area, or insulate, it |
| to supply the world's needs for one full year. | | | | while still allowing extra lighting. Interior rooms can be |
| Harnessing costs are relatively small and greenhouse | | | | naturally illuminated by placing skylights or light tubes in |
| gas emissions are zero. | | | | the roof of the building. Retractable awnings and tinting |
| Basically, solar power is used to generate heat that | | | | can be used to control the sun's affect on individual |
| can be harnessed to provide an energy source for | | | | rooms. |
| other appliances. Direct applications of solar heating | | | | Heating water for domestic use is another form of |
| are household heating, water heating, ventilation | | | | passive solar power that is cost effective and easy to |
| systems and cooking methods. Harnessed solar | | | | install. By placing a solar panel on the roof, or a suitable |
| energy can also be used to create steam that will | | | | stand that faces the sun, copious amounts of hot |
| drive a piston engine, create an electric current that | | | | water can be produced and stored in an insulated |
| can charge batteries and provide power for household | | | | receiver. |
| appliances. | | | | By installing a vertical tube, or passage in a wall that |
| Photovoltaic cells convert the sun's rays into electricity | | | | faces the sun, a building, or room can be passively |
| and were originally recognized many years ago. They | | | | cooled by using the heating power of the sun's rays. |
| were first put to practical use nearly fifty years ago, | | | | The theory is that the air in the tube is heated by the |
| when the US Government used them on their early | | | | sun, which causes the air to rise and be exhausted |
| space satellites, as an effective source of energy. | | | | through a small chimney on the roof. Air from inside |
| They are in common use today as an energy source | | | | the building, will be drawn through a vent in the wall that |
| for solar powered calculators. Massive groups of | | | | connects to the ventilation tube, allowing a constant |
| these cells are used to make solar modules, which | | | | stream of fresh, cool air to pass through the room. |
| form a photovoltaic array that can be duplicated to | | | | As conventional energy costs continue to soar, people |
| provide an abundance of electrical power. This form | | | | are encouraged to implement the many passive solar |
| of renewable energy is becoming ever more popular in | | | | energy sources that are available. They are easily |
| remote areas, and can also be fed into a grid system, | | | | installed, efficient, cost little or nothing to run and are |
| where it can be tapped by a number of users in other | | | | environmentally friendly. |