| If you measure the sun's power in terms that compare | | | | concentrate the solar energy into the tubes. |
| it to the energy produced by oil, the sun gives enough | | | | - Heating water using solar power was the first use of |
| energy to the Earth in about 20 minutes to fulfill all of | | | | solar energy, starting in the early twentieth century. |
| the planet's requirements for a year! And in fact, solar | | | | These systems can be used year round (even in cold |
| energy already provides a great deal of power to the | | | | climates when combined with use of anti-freeze), and |
| Earth by transforming through a variety of natural | | | | are now commonly seen in many countries. |
| means, by heating surfaces, influencing weather | | | | - Solar powered air heaters mounted to a wall are |
| phenomenon, and even through photosynthesis, which | | | | used primarily to heat the ventilation air for buildings |
| provides plants with the energy they require in order to | | | | that have large open spaces. The air comes through |
| grow. | | | | holes in a dark metal container where it is heated and |
| So what are some ways that we on Earth can take | | | | is then taken into the building. |
| better advantage of all this freely distributed solar | | | | - A newer form of solar collector involves the use of |
| power? Energy from the Sun can be processed in | | | | mirrors to run steam turbines that create electricity. |
| three primary ways: | | | | These thermal power systems are becoming |
| 1. Passive Solar Techniques | | | | particularly popular in hot, dry climates where there is a |
| This refers to the ways that the sun's light and heat | | | | great deal of both sunlight and open land. |
| can be used to advantage without any further | | | | - Evacuated tube collectors can also be used to |
| processing needed. This category includes things as | | | | power cooling systems by taking the high temperature |
| simple as allowing sunlight to stream through a window | | | | heat from the tubes. This technology can help reduce |
| and into a home, warning the rooms naturally. | | | | the use of natural gas, which would ordinarily be used |
| Some ways to take advantage of passive solar | | | | to run cooling systems. |
| techniques would be use of energy efficient windows, | | | | 3. Solar Cells |
| and planning the best placement of concrete and | | | | Solar energy can be turned into electricity through use |
| ceramic floors so that they can collect and store more | | | | of photovoltaic (PV) solar cells. This method uses |
| sunlight. | | | | modules each consisting of an array of solar cells |
| A building that has been optimized for passive solar | | | | which are connected together inside a glass covered |
| may have additional windows placed on the south side, | | | | container. Any number of these modules can be used |
| for instance, to take advantage of the most hours of | | | | together in order to produce a larger or smaller |
| sun per day. Even something this simple can greatly | | | | amount of power, depending on what is needed for a |
| reduce home energy bills. | | | | particular application. PV solar cells are usually made |
| 2. Collection of Solar Energy | | | | from crystalline silicon or quartz. Other materials that |
| Solar power can be collected and stored as heat | | | | can be used are amorphous silicon, cadmium telluride, |
| energy. Solar Collectors take in solar radiation and then | | | | or copper indium di-selenide. |
| concentrate it into very defined areas, increasing the | | | | The cost of making PV cells and solar panels |
| strength and heat of the energy. These can be used | | | | (modules) has been decreasing recently with the |
| to heat or cool water or rooms, or to create power to | | | | development of new manufacturing techniques. These |
| enable air or liquids to transfer heat to a separate | | | | are widely used to provide power for remote |
| location. | | | | stand-alone structures such as lighthouses and radio |
| Different types of solar collectors include: | | | | towers, and for heat and lighting in developing |
| - A set of pipes that fits into a copper or metallic flat | | | | countries. The use of solar panels to supply energy for |
| plate that has been insulated inside a box under glass. | | | | home use is increasing in developed countries as well, |
| The sun streaming through the glass produces heat in | | | | and many governments are encouraging their use by |
| the plate, which is then directed into the liquid in the | | | | providing financial incentives to those who install solar |
| pipes. This is known as a "Flat Plate Collector". | | | | panels for their residences. In addition, improvements in |
| - A tube is a more efficient way of collecting solar | | | | the process of constructing solar panels is now making |
| energy at high temperatures. This type of solar | | | | it much easier for people to build their own, at a |
| collector is made from a series of tubes, which are | | | | dramatic cost saving over commercial panels. It is now |
| then installed in separate glass vacuum tubes. These | | | | quite feasible for a homeowner to save a great deal |
| prevent the inner tubes from cooling, and ensure that | | | | on electricity by building and installing their own solar |
| more heat is sent into the fluid. At extremely high | | | | panels. |
| temperatures, a reflector may be used in order to | | | | |