The scientific community has been on a swift curve toward better ways to harness the suns energy. There are drastic limitations on Earth bound solar collection due to atmospheric absorption which causes a decrease in the energy emitted by the sun. However, from space nothing will stand in the way of complete garnering and retaining of all accessible sunlight. In fact, traveling in geosynchronous orbit will position satellites in the perfect realm for collection of constant, direct and completely uninterrupted solar energy.
From Germany to Japan scientists are investigating the best ways to apply space based solar power harvesting. Most are in agreement that the best solutions are to utilize microwave amplification via stimulated emission of radiation or some variation thereof to beam energy from space to Earth.The benefit of employing microwaves lies in the fact that, when the frequencies are kept at approximately10 gigahertz or below, they have the ability to penetrate the Earth’s atmosphere without the concern of energy loss through absorption, even with considerations of adverse weather conditions. With that said, the issue with microwaves is that they are prone to spreading, which then must be combated with ever increasing receiver sizes, dependent on the distance the waves must travel to their destination.
Considering most existing satellites function above the earths surface at an orbit around 21,750 miles, land locked receivers would have to span a relatively vast area, perhaps literally hundreds of square miles. The idea is slightly less than practical in its simplest form. To combat this, the idea of a narrowed beam tuned to a wavelength that would not harm humans but would still retain its durability has been proposed as one of the most reasonable options. Such a beam would have a fixed reception point on the Earth’s surface.
Another, slightly more elaborate idea, presented at the International Union of Radio Science’s 30th General Assembly, was to virtually permanently dispel the issue by utilizing both lasers and microwaves. Alone, lasers are unstable and easily scattered; in theory a laser would beam the solar energy from a platform in space to an unmanned craft sitting just above the Earth’s surface, in fact, only 12 miles above. The craft would then transform the laser to microwaves and complete the transfer of energy to the ground receiver which could then be scaled down to a mere 130 feet.
Despite what mat seem like hindering factors to the project scientists around the world agree that in the next 10 to 20 years there will be functional solar harvesting from space. Potentially it could tale the place of solar panels for homeowners, however the cost would be astronomical. Whole cities won’t be powered, that will take significant advances in spaceflight technology and efficiency of solar usage but major staples such as hospitals or military will be able to utilize the resource. When can you expect solar power to your house from space? Well, when it is more economic to get the equipment where it is needed, in space, it will have the potential to become commonplace.