What were once perceived to be perfect and inexhaustible energy sources, coal, oil and natural gas, are now seen as dirty and diminishing. The concept of a source of energy that is clean, and will be usable to the end of time, has compelled research into renewable energy from such sources as wind, geothermal and solar power. Solar power seems to be the most widely accessible renewable energy source.
Renewable Energy
Renewable energy never runs out. Coal and oil were substances that were created by a limited amount of organic material existing under pressure for millions of years. While coal and oil are being created today by natural processes, this is occurring at an infinitesimal rate compared to the rate they are used. Geothermal energy harnesses heat generated from the center of the Earth. This heat will likely not diminish in our lifetimes, but it is also not easily available in most areas. Similarly wind is powerful, but does not occur reliably in all regions. Few places on Earth don’t get some sunlight daily. The sun produces energy through nuclear explosions from chemical reactions. The magnitude of the reactions is 100,000 times more energy than typical reactions on Earth, according to Benjamin Crowell. The sun likely will continue to shine long after life on Earth has disappeared.
Solar Heat
The power of the sun comes in two forms: heat and light. The sun can be 10 to 22.5 million degree Fahrenheit at the core. It provides all the heat for Earth. The heat of the sun’s rays can be used to boil water, which can be used directly as hot water for bathing, washing or heating a building, or it can be used indirectly by using the boiling water to power engines.
Solar Light
Solar light can be used directly in the form of skylights to illuminate buildings or it can be converted into electricity by photovoltaic cells. A “cell” is made of semiconductor material; when light hits it, it emits an electron. These captured electrons can be made to form a current of electricity. This electricity can be used to power anything, such as a light source or a motor.
Solar Collectors
Solar collectors might be something as simple as a wall or floor of bricks to retain the heat of the day, water running through black tubes to create hot water for showers, or something more complex such as photovoltaic cells. Satellites often have solar collectors that provide power to the satellite itself. Dr. Peter Edward Glaser, a Massachusetts Institute of Technology researcher, introduced the idea that these satellites could collect the energy from the sun, since in aggregate they do not experience day and night. There are always some satellites facing the sun, thus they could continually beam electricity down energy to Earth. This technology is still being refined.
Disadvantages
Most homes and businesses were not built with solar power in mind, so they need to be retrofitted to include things like skylights, heat sinks and hot water systems. Some of the equipment can be expensive. Photovoltaic cells have no moving parts and require no maintenance, but they do wear out. Locating the solar collectors can be a challenge. In some locations the sun is obscured by clouds much of the time or at inconvenient intervals.
Member Comments