The notion of Space-Based Solar Power (SBSP) is not new. There has long been talk of 24-hour-a-day solar power beamed from space via microwave to any point on earth. However, a new company named Space Energy, Inc. believes it well placed to develop SBSP satellites to generate and transmit electricity to receivers on the Earth’s surface. To do this, the company plans to create and launch a prototype satellite into low earth orbit (LEO).
There’s only one hitch: this concept is based on as yet unproven technology.
SBSP was mooted over 40 years ago by scientist Dr. Peter Glaser. Since then, in response to periodic energy crises, the plan has been re-evaluated from time to time by the U.S. Department of Energy, NASA, major aerospace companies and countries such as Japan and India.
Solar power satellites are massive arrays of photovoltaic panels assembled in orbit, which utilise microwave radio waves to transmit solar power to large receiving antennas on Earth. The resulting power can either supplement, or be a substitute for, conventional electricity sources.
The advantage of putting large solar collectors in geosynchronous Earth orbit (GEO), about 36,000 kilometres (22,500 miles) above Earth, is that it uses the constant and unobstructed output of the Sun, unaffected by the Earth’s day and night or weather cycles.
Ground-based solar power provides a vital and valuable addition to the Earth’s energy needs, but is limited by these factors:
* Poor direct sunlight at higher and lower latitudes
* Variable seasons
* Atmospheric blocking of sunlight
Given that none of these factors applies in outer-space, an orbiting SBSP station can supposedly provide an estimated 6-8 times more power than a comparable solar cell on the Earth’s surface.
Space Energy, Inc claims that a successful long-range wireless power transmission test was conducted in mid-2008, which supposedly transmitted a microwave beam between two Hawaiian Islands across 148 kilometres – more than the distance from the surface of the Earth to the boundary of space. They claim this test demonstrated the technical feasibility of transmitting SBSP to Earth.