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Photovoltaic effect: the generation of a voltage and/or a current by absorption of light in some material or combination of materials. | Photovoltaic effect: the generation of a voltage and/or a current by absorption of light in some material or combination of materials. | ||
- | Photovoltaics: | + | **Photovoltaics: |
- | Photovoltaic cell (see also Solar cell): is a device that converts light energy into electrical energy by the photovoltaic effect. Sometimes the term solar cell is reserved for devices intended specifically to capture energy from sunlight, while the term photovoltaic cell is used when the source is unspecified. | + | **Photovoltaic cell** (see also Solar cell): is a device that converts light energy into electrical energy by the photovoltaic effect. Sometimes the term solar cell is reserved for devices intended specifically to capture energy from sunlight, while the term photovoltaic cell is used when the source is unspecified. |
- | Quantum Dot: also called a semiconductor nanocrystal, | + | **Quantum Dot:** also called a semiconductor nanocrystal, |
- | Quantum efficiency (QE): is the ratio of the number of charge carriers collected by the solar cell to the number of photons — or packets of light — of a given energy shining on the solar cell. | + | **Quantum efficiency (QE):** is the ratio of the number of charge carriers collected by the solar cell to the number of photons — or packets of light — of a given energy shining on the solar cell. |
- | Renewable energies: Renewable describes any energy source whose availability or supply will not be permanently depleted as a result of exploitation over a period of time that is meaningful to people. Fossil fuels (coal, oil and natural gas), which formed over millions of years of geological conditioning, | + | **Renewable energies:** Renewable describes any energy source whose availability or supply will not be permanently depleted as a result of exploitation over a period of time that is meaningful to people. Fossil fuels (coal, oil and natural gas), which formed over millions of years of geological conditioning, |
- | Semi-conductor: | + | **Semi-conductor: |
- | Short-circuit current (Isc): is the current produced when the positive and negative terminals of the cell are short-circuited, | + | **Short-circuit current (Isc):** is the current produced when the positive and negative terminals of the cell are short-circuited, |
- | Solar cell (see also " | + | **Solar cell (see also " |
Fundamentally, | Fundamentally, | ||
- | 1. photogeneration of charge carriers (electrons and holes) in a light-absorbing material, and 2. separation of the charge carriers to a conductive contact that will transmit the electricity. This conversion is called the photovoltaic effect. | + | 1. photogeneration of charge carriers (electrons and holes) in a light-absorbing material, and |
+ | 2. separation of the charge carriers to a conductive contact that will transmit the electricity. This conversion is called the photovoltaic effect. | ||
Photovoltaics is the field of research related to solar cells. Solar cells have many applications. Historically solar cells have been used in situations where electrical power from the grid is unavailable, | Photovoltaics is the field of research related to solar cells. Solar cells have many applications. Historically solar cells have been used in situations where electrical power from the grid is unavailable, | ||
- | + | **Solar cell's energy conversion efficiency**: is the percentage of power converted from absorbed light to electrical energy and then collected when a solar cell is connected to an electrical circuit. | |
- | Solar cell's energy conversion efficiency: is the percentage of power converted from absorbed light to electrical energy and then collected when a solar cell is connected to an electrical circuit. | + | |
Or: | Or: | ||
The efficiency of a solar cell is defined as the percentage of solar energy falling on its surface that is converted into electrical energy. | The efficiency of a solar cell is defined as the percentage of solar energy falling on its surface that is converted into electrical energy. | ||
Under a typical sunny day, a one square meter surface of solar cells exposed to the sun around noontime will receive approximately 1,000 W. When for instance multi silicon cells convert 15% of this into electricity, | Under a typical sunny day, a one square meter surface of solar cells exposed to the sun around noontime will receive approximately 1,000 W. When for instance multi silicon cells convert 15% of this into electricity, | ||
- | Solar Cycle: The 11-year variation in the Sun's magnetic field and all the features caused by it such as the number of sunspots, coronal mass ejections and solar flares. The variation is seen as an increase and decrease of solar activity on a regular basis, lasting approximately 11 years from beginning of end. | + | **Solar Cycle:** The 11-year variation in the Sun's magnetic field and all the features caused by it such as the number of sunspots, coronal mass ejections and solar flares. The variation is seen as an increase and decrease of solar activity on a regular basis, lasting approximately 11 years from beginning of end. |
- | Solar-hydrogen fuel cell energy system: a photovoltaic array produces electricity to provide for the primary electricity load (home), as well as enough excess electricity to run an electrolyzer which converts water into hydrogen. The hydrogen produced will be reserved in a storage tank until needed, at which point it will be converted back into electricity through means of a fuel cell. To increase energy efficiency. | + | **Solar-hydrogen fuel cell energy system:** a photovoltaic array produces electricity to provide for the primary electricity load (home), as well as enough excess electricity to run an electrolyzer which converts water into hydrogen. The hydrogen produced will be reserved in a storage tank until needed, at which point it will be converted back into electricity through means of a fuel cell. To increase energy efficiency. |
If 1% of the world' | If 1% of the world' | ||
- | Solar panels: are devices for capturing the energy in sunlight. The term solar panel can be applied to either solar hot water panels (usually used for providing domestic hot water) or solar photovoltaic panels (providing electricity). | + | **Solar panels:** are devices for capturing the energy in sunlight. The term solar panel can be applied to either solar hot water panels (usually used for providing domestic hot water) or solar photovoltaic panels (providing electricity). |
- | Solar power: describes a number of methods of harnessing energy from the light of the Sun. It has been present in many traditional building methods for centuries, but has become of increasing interest in developed countries as the environmental costs and limited supply of other power sources such as fossil fuels are realized. | + | **Solar power:** describes a number of methods of harnessing energy from the light of the Sun. It has been present in many traditional building methods for centuries, but has become of increasing interest in developed countries as the environmental costs and limited supply of other power sources such as fossil fuels are realized. |
- | Solar Power Concentrated (PhotoVoltaics) (CSP;CPV): use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam capable of producing high temperatures and correspondingly high thermodynamic efficiencies. Concentrating solar is generally associated with solar thermal applications but concentrating photovoltaic (CPV) applications exist as well and these technologies also exhibit improved efficiencies. CSP systems require direct | + | **Solar Power Concentrated (PhotoVoltaics) (CSP;CPV):** use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam capable of producing high temperatures and correspondingly high thermodynamic efficiencies. Concentrating solar is generally associated with solar thermal applications but concentrating photovoltaic (CPV) applications exist as well and these technologies also exhibit improved efficiencies. CSP systems require direct |
- | Solar (ir)radiation: | + | **Solar (ir)radiation: |
- | Daily total solar irradiation: | + | - Daily total solar irradiation: |
| | ||
- | Solar wind: A stream of particles, mostly electrons and protons, flowing out from the Sun at speeds of 5-10 km/s. As it flows out, the solar wind accelerates and can reach speeds as high as 900 km/s. The solar wind is the result of the hot solar corona expanding into space. | + | **Solar wind:** A stream of particles, mostly electrons and protons, flowing out from the Sun at speeds of 5-10 km/s. As it flows out, the solar wind accelerates and can reach speeds as high as 900 km/s. The solar wind is the result of the hot solar corona expanding into space. |
Sun-Earth distance: varies during the year, but on average it is approximately 150,000,000 km or 93,000,000 miles. | Sun-Earth distance: varies during the year, but on average it is approximately 150,000,000 km or 93,000,000 miles. | ||
- | Under-voltage: | + | **Under-voltage: |
- | Ultra Violet-Light (UV): means " | + | **Ultra Violet-Light (UV):** means " |
- | Wp - Watt-piek | + | **Wp - Watt-piek:** Max. theoretical power of a solar panel with a surface of 1m², measured at a temperature of 25°. A standard measure (unit) being used to compare the power of different solar panels. In practice a solar panel reaches in general only 80% of the Watt-piek power. |
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Sources: | Sources: | ||
+ | |||
www1.eere.energy.gov/ | www1.eere.energy.gov/ | ||
www1.eere.energy.gov/ | www1.eere.energy.gov/ |