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Home > Student Gazette > Sustainable Development

Solar Power Satellites

Calista D. , Julia D. , Rayann L.

30 June 2010

The world is changing in so many ways every single day. It’s being upgraded with new technology, we’re learning new scientific ways of doing things, and there are many economically friendly things on the horizon. One future type of technology that could eventually become very economically and ecologically friendly is solar power satellites. Solar power satellites (better known as SPS’s) do not actually exist as yet, but plans are ready for them to be developed if governments and/or corporations want to make the commitment. SPS’s could start a new technological way of life. They don’t need to depend on anything except the sunlight beyond Earth’s atmosphere and the technology to gather and microwave beam the solar energy to collectors on Earth. SPS’s don’t deplete fossil resources. They don’t depend on water or fertilizer, either, like growing plants (like corn) for some forms of alternative energy do. SPS’s are also very different because they don’t use nuclear fission-based power plants which produce toxic waste which is bad for the planet.

Solar power satellites are a new concept for producing energy. They would be positioned above the Earth’s atmosphere. Microwaves are the electricity converted from solar power that would be collected by a solar power satellite. After being changed, microwaves would be sent through the atmosphere to the Earth’s surface. The Earth’s surface is where the microwaves are taken in by large collectors and turned back into electricity.

The Earth receives one thousand, four hundred watts of sunlight per square meter. On Earth, this is cut in half because of the day to night span cycle. The sun has an oblique angle, which means this is cut in half again just to complement the typical space on Earth. In addition, the light is then cut down more because of atmospheric dust and clouds. In the end, sunlight finally reaching the Earth is only about one eighth of the brightness it should be. This is a waste of the sun’s power.

During the 1970’s, people became very interested in solar power satellites. In more recent years, a renewed interest has come up on the subject of solar power satellites. This interest was mostly due to concerns about global warming, which was a result of carbon dioxide emissions from fossil fuel combustion.

Solar power satellites could be constructed in space. About ninety eight percent of the solar power satellites mass could consist of materials from the moon. For this to occur, there must be a lunar infrastructure. That means that either worksites on the moon or orbital space stations, like the International Space Station, would have to have human workers, along with robotic machinery, would be used. There are companies already in existence which have planned for this kind of enterprise. PERMANENT.COM is a website which shows a lot of the technology that would be needed.

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Solar Power Satellite
(Example of what a solar power satellite would look like),2933,301479,00.html

The world needs clean energy. Gathering energy from the sunlight in space is a wise idea because the lifetime of the sun is about four to five billion years, which means that there is a long-term energy source. There are many advantages of Solar Power. One example of an advantage would have to be that unlike oil, ethanol, gas, and coal plants, the solar power from space solar power does not emit things called “green house gases.” (Any atmospheric gas that contributes to the greenhouse affect just by absorbing infrared radiation) Space solar power does not have to use increasingly scarce fresh water resources, as nuclear power plants and coal do. This is better for the environment. Space solar power also does not compete for increasingly valuable farming land or depend on natural-gas-derived fertilizer, unlike bio-ethanol or bio-diesel. Food can continue to be a very major export instead of a provider for fuel. Space solar power will not produce hazardous wastes, unlike nuclear fission-based power plants which for hundreds of years will need to have toxic wastes stored and guarded. During the entire span of a full day, space solar power would be available, unlike terrestrial solar and wind power plants. Space solar power does not provide easy targets for terrorists, unlike nuclear power plants and coal. Bio-ethanol or bio-diesel are also different because space solar power doesn’t compete for the always increasing value of farm land.

However, solar power satellites are not perfect. They have quite a few disadvantages. One disadvantage is the high development costs. The costs of solar power satellites are extremely large. It is less expensive than the military budget, or the costs of global warming, and climate change, but it is still very expensive.

There are many technological devices that would go along with developing SPS’s. One good thing is that there could be environmentally and economically friendly launch methods instead of rocket launches. Rockets have very high launch rates and prices. They may also cause a lot of atmospheric pollution all by themselves.

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ribbon climber
(Left: Example of how a ribbon climber would work)

One interesting possible solution is called a Ribbon Climber, better known as Space Elevator Ribbon, which would raise items slowly through the atmosphere from a line attached to a geosynchronous satellite. The payload (cargo) would then be switched to a tether, which would launch the cargo to the destination in space.

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Space Tether
(Right: Example of what a space tether might look like)

In conclusion, many people of Earth have become more and more environmentally friendly each day we’re on Earth. And with new technology like Solar Power Satellites, humans are even closer to more success. Technology is getting better for the planet and our goods. Less pollution can bring people more happiness by allowing human beings to live in a healthy environment that’s free of pollution.



David, Leonard. “Space Power for an Energy-Hungry Earth?” Senior Space writer posted: 07:05 am ET April 21 2000

Potter, Seth. “Solar Power Satellites” Research Scientist, New York University

Potter, Seth. “Image of Traditional SPS: SSI”

Smith Glenn. “Harvest the Sun-From Space” Published July 23, 2008