Solar power is the conversion of sunlight into electricity, either directly using photovoltaics), or indirectly using concentrated solar power. Concentrated solar power systems use lenses or mirrorsto focus a large area of sunlight into a small beam. Photovoltaics convert light into electric current using the photoelectric effect.
Solar power again emerged in 1970’s, as oil prices soared on the open market. This was a great opportunity for the use of solar power to increase. Around 3,000 photovoltaic systems were set up. In the 1990’s people began to realize that total dependence on foreign countries for oil and petroleum was a cause for concern.
The beginning of the 20th century saw the first solar fields. Schuman in Tacony (US, 1911) created a Solar plant with 20 kW of total output!. His next solar plant in Maadi (Egypt, 1912) was designed in 5 rows of 62 m of parabolic mirrors for a total output of 88 kW!
Frank Schumancreated then the Sun Power Co and his dream was to build in the Sahara 52.600 km² of mirror collectors to produce 198 MW which were equivalent to the world energy consumption in 1909.
In 1977, the Air Force Concentrating Photovoltaic Array study program conducted by Rockwell International concluded that solar concentrator arrays can survive the tough environments of outer space. Rockwell developed a preliminary design for a hardened solar concentrator. Rockwell also studied a way to use mirrors that concentrated the sunlight in a solar furnace to heat fluid, powering electricity-generating turbine engines. Involved in the Rockwell studies were engineers who carried their expertise with them when the company's space systems became part of Boeing in 1996. Later studies showed that silicon solar cells had a higher life expectancy than the thermal engine system, so the Boeing solar power satellite became the system of choice.
Light (photons) striking certain compounds, in particular metals, causes the surface of the material to emit electrons. Light striking other compounds causes the material to accept electrons. It is the combination of these two compounds that can be made use of to cause electrons to flow through a conductor, and thereby create electricity. This phenomenon is called the photo-electric effect. Photovoltaic means sunlight converted into a flow of electrons (electricity).
Solar power is a rapidly developing energy source in Australia and around the world. The potential for using the sun to directly supply our power needs is huge, every day Earth. This is due to the development of technology such as the solar panel, which utilizes the energy channelling capacity of the photovoltaic cell.
Japan launched the IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) aboard an H-IIA rocket in May 2010. It gathered energy for propulsion from sunlight pressure (photons) by means of a square membrane measuring 20 meters diagonally. On December 8, 2010, IKAROS passed by Venus at about 80,800 km distance, successfully completing its planned mission.
Solar water heating systems for buildings have two main parts: a solar collector and a storage tank. Typically, a flat-plate collector—a thin, flat, rectangular box with a transparent cover—is mounted on the roof, facing the sun collecting the solar energy. The sun heats an absorber plate in the collector, which, in turn, heats the fluid running through tubes within the solar collector. To move the heated fluid between the collector and the storage tank, a system either uses a pump or gravity, as water has a tendency to naturally circulate as it is heated. Systems that use fluids other than water in the collector's tubes usually heat the water by passing it through a coil of tubing in the tank.
According to the California Energy Commission, solar energy, in particular photovoltaic produced power has grown massively in recent years. Prior to 2002, only 1,675 grid connected photovoltaic installations were registered with the commission. Fast forward to 2008, and there are 29,628 installations recorded. That's a 17x increase in just 6 years! In just the last 3 years, total installations have more than doubled, with 14,058 installs in 2005.
The harnessing of solar energy is not new in fact, development of solar energy dates back more than 100 years, to the middle of the industrial revolution. Several pioneering solar power plants were constructed to produce steam from the heat of the sun, which was used to drive the machinery of the time. At the same time, Henri Becquerel discovered the photovoltaic effect; that is, the production of electricity directly from the sun. Becquerel's research was investigated and extended by, among others, Werner Siemens. Photovoltaic power remained a curiosity for many years, since it was very inefficient at turning sunlight into electricity.
The period from the 1970's to the 1990's saw quite a change in the usage of solar cells. They began showing up on railroad crossings, in remote places to power homes, Australia used solar cells in their microwave towers to expand their telecommunication capabilities. Even desert regions saw solar power bring water to the soil where line fed power was not an option!
In 1891 the first commercial solar water heater was patented by the father of American solar energy, Clarence Kemp.
William J. Bailley of the Carnegie Steel Company in 1908 invented a solar collector with copper coils and an insulated box.
A book published by the Libbey-Owens-Ford Glass Company in 1947 showcased the fourty-nine greatest American solar architects.
Early 1950's, A process for producing crystalline silicon of high purity was developed, called the Czochralski meter.
Many consumers assume that solar power is a relatively new power source but this could not be further from the truth. The sun has been known to be a source of energy dating back to ancient times. The ancient Greek and Native Americans were the first to use solar power to their benefit, dating back as early as 400BC. Native Americans and the ancient Greek built their houses into the side of hills to take advantage of the heat storage from the sun during the day that would then be released during the night.
The Romans took their knowledge of the sun being a source of energy as they were the first people to use glass windows to trap the warmth of the sun in their homes. They were so serious about the preservation of this solar energy that they erected glass houses to create the right conditions to grow plants and seeds.
Acciona recently completed Nevada Solar One, a 64 MW solar trough power plant near Boulder City, Nevada. Acciona and the UNLV Center for Energy Research, along with The National Renewable Energy Laboratory (NREL) are working together to monitor weather conditions and to consider how energy storage may fit at the site.
In order to make solar energy competitive with other types of energy, it will be critical to reduce "soft cost" barriers, such as permitting, zoning and the cost to hook a solar system to a local electrical grid. To spur change, Secretary Chu announced $12 million in funding for 22 regional teams competing in the Energy Department’s "Rooftop Solar Challenge.” The map above details all 22 teams' locations, the projects each team will be undertaking, and the amount of funding they've been awarded.