Space-based solar power (SBSP) (or historically space solar power (SSP)) is a system for the collection of solar power in space, for use on Earth. SBSP differs from the usual method of solar power collection in that the solar panels used to collect the energy would reside on a satellite in orbit, often referred to as a solar power satellite (SPS), rather than on Earth's surface. In space, collection of the Sun's energy is unaffected by the day/night cycle, weather, seasons, or the filtering effect of Earth's atmospheric gases.The world Radiation Centre's 1985 standard extraterrestrial spectrum for solar irradiance is 1367 W/m2. The integrated total terrestrial solar irradiance is 950 W/m2. Therefore, extraterrestrial solar irradiance is 144% of the maximum terrestrial irradiance. A major interest in SBSP stems from the length of time the solar collection panels can be exposed to a consistently high amount of solar radiation. For most of the year, a satellite-based solar panel can collect power 24 hours per day, whereas a land-based station can collect for only 12 hours per day, yielding lower power collection rates around the sunrise and sunset hours.
The collection of solar energy in space for use on Earth introduces the new problem of transmitting energy from the collection point, in space, to the place where the energy would be used, on Earth's surface. Since wires extending from Earth's surface to an orbiting satellite would be impractical, many SBSP designs have proposed the use of microwave beams for wireless power transmission. The collecting satellite would convert solar energy into electrical energy, which would then be used to power a microwave emitter directed at a collector on the Earth's surface. Dynamic solar thermal power systems are also being investigated.
Some problems normally associated with terrestrial solar power collection would be eliminated by such a design, such as dependence on meteorological and weather conditions, and the panels being prone to corrosion. Other problems may take their place though, such as cumulative radiation damage or micrometeoroid impacts.
Advantages
The SBSP concept is attractive because space has several major advantages over the Earth's surface for the collection of solar power. There is no air in space, so the collecting surfaces would receive much more intense sunlight, unaffected by weather. In geostationary orbit, an SPS would be illuminated over 99% of the time. The SPS would be in Earth's shadow on only a few days at the spring and fall equinoxes; and even then for a maximum of 75 minutes late at night when power demands are at their lowest. This characteristic of SBSP avoids the expense of storage facilities (dams, oil storage tanks, coal dumps) necessary in many Earth-based power generation systems. Additionally, SBSP would have fewer or none of the ecological (or political) consequences of fossil fuel systems.
SBSP would also be applicable on a global scale. Nuclear power especially is something many governments are reluctant to sell to developing nations, where political pressures might lead to proliferation of nuclear weapons technology. SBSP poses no known potential threat.
The SBSP concept is attractive because space has several major advantages over the Earth's surface for the collection of solar power. There is no air in space, so the collecting surfaces would receive much more intense sunlight, unaffected by weather. In geostationary orbit, an SPS would be illuminated over 99% of the time. The SPS would be in Earth's shadow on only a few days at the spring and fall equinoxes; and even then for a maximum of 75 minutes late at night when power demands are at their lowest. This characteristic of SBSP avoids the expense of storage facilities (dams, oil storage tanks, coal dumps) necessary in many Earth-based power generation systems. Additionally, SBSP would have fewer or none of the ecological (or political) consequences of fossil fuel systems.
SBSP would also be applicable on a global scale. Nuclear power especially is something many governments are reluctant to sell to developing nations, where political pressures might lead to proliferation of nuclear weapons technology. SBSP poses no known potential threat.
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