Insolation is a measure of incident solar radiation energy received by a surface area per unit time. It is the primary variable affecting equilibrium temperature. In scientific literature, it is commonly expressed in watts per square meter (W/m2). Photovoltaics are commonly measured in kWh/(kWp÷y) (kilowatt hours per year per kilowatt peak rating).
Objects at Earth distance (1AU) from the sun receive approximately 1366 W/mò. This solar constant includes all types of solar radiation, not just the visible light. However, because of day/night cycles, seasons, and the Earth's atmosphere, a given area on the Earth's surface receives only an average of 250W/m2 insolation. This is of course mediated by the latitude of the location and the weather (cloudiness). Due to the projection effect, less insolation is received at higher latitudes. The figures can be obtained from an insolation map or by city or region from insolation tables that were generated with historical data over the last 30ââ¬â50 years. Insolation values range from 800 to 950 kWh/(kWp÷y) in Norway to up to 2,900 in Australia.
This projection effect is used in both passive solar thermal design and in the design of Solar Power Systems.
For a given surface area exposed to sunlight, some of the solar radiation is absorbed some is reflected. Most commonly, the absorbed solar radiation causes radiant heating, however, some systems may store or convert some portion of the absorbed radiation, as in the case of photovoltaics or plants. The proportion of radiation reflected or absorbed depends on the object's reflectivity or albedo, respectively.
The existence of nearly all life on Earth is fueled by light from the sun. Most autotrophs, such as plants, use the energy of sunlight, combined with minerals and air, to produce simple sugarsââ¬âa process known as photosynthesis. These sugars are then used as building blocks and in other synthetic pathways which allow the organism to grow.
Heterotrophs, such as animals, use light from the sun indirectly by consuming the products of autotrophs, either directly or by consuming other heterotrophs. The sugars and other molecular components produced by the autotrophs are then broken down, releasing stored solar energy, and giving the heterotroph the energy required for survival. This process is known as respiration.
Objects at Earth distance (1AU) from the sun receive approximately 1366 W/mò. This solar constant includes all types of solar radiation, not just the visible light. However, because of day/night cycles, seasons, and the Earth's atmosphere, a given area on the Earth's surface receives only an average of 250W/m2 insolation. This is of course mediated by the latitude of the location and the weather (cloudiness). Due to the projection effect, less insolation is received at higher latitudes. The figures can be obtained from an insolation map or by city or region from insolation tables that were generated with historical data over the last 30ââ¬â50 years. Insolation values range from 800 to 950 kWh/(kWp÷y) in Norway to up to 2,900 in Australia.
This projection effect is used in both passive solar thermal design and in the design of Solar Power Systems.
For a given surface area exposed to sunlight, some of the solar radiation is absorbed some is reflected. Most commonly, the absorbed solar radiation causes radiant heating, however, some systems may store or convert some portion of the absorbed radiation, as in the case of photovoltaics or plants. The proportion of radiation reflected or absorbed depends on the object's reflectivity or albedo, respectively.
The existence of nearly all life on Earth is fueled by light from the sun. Most autotrophs, such as plants, use the energy of sunlight, combined with minerals and air, to produce simple sugarsââ¬âa process known as photosynthesis. These sugars are then used as building blocks and in other synthetic pathways which allow the organism to grow.
Heterotrophs, such as animals, use light from the sun indirectly by consuming the products of autotrophs, either directly or by consuming other heterotrophs. The sugars and other molecular components produced by the autotrophs are then broken down, releasing stored solar energy, and giving the heterotroph the energy required for survival. This process is known as respiration.