Wireless power from space: energy salvation?
Consider this: There's more energy from the sun striking the earth every minute than the amount of fossil fuel used by the world in a year.
Solar power is the most relied on source of clean, renewable energy and ever larger photovoltaic power plants are mushrooming around the world. But there's another way to exploiting solar power, and that is to capture it in space and convey it to the Earth by wireless means using microwave transmission.
The idea of sending solar power satellites into orbit has been around since the 1970s, but interest has revived in recent years. Environmental disasters such as the colossal BP oil spill in the Gulf of Mexico could only work to accelerate support.
DK Matai's report last week about Japan's plan to send its first solar-panel-equipped satellite into space this decade appeared in the Huffington Post. Led by The Ministry of Economy, Trade and Industry (METI) and the Japan Aerospace Exploration Agency, the objective of the project is to first test beaming electricity from space through the ionosphere, the outermost layer of the earth's atmosphere. Matai said that such a satellite could eventually beam Gigawatt-strong streams of power down to earth wirelessly, each enough to power nearly 300,000 homes eco-efficiently. Experts predict this kind of commercial power delivery from space to take 20 years to develop.
Like terrestrial capture, space solar power (SSP) provides a source that is virtually carbon-free and sustainable. The difference is that it bypasses many of the difficulties, including cloudy days, zoning laws, and weathering and degradation in performance. With the satellites positioned in geosynchronous orbit, power collection could occur 24 hours a day. Moreover, delivery of power can be carried out in any type of weather condition when the right transmission frequency is selected.
The challenges facing space solar power are plentiful, and launch cost is chief among them from a practical economic viewpoint. Another hurdle is developing space based assembly techniques to construct arrays. Eclipsing the financial and technical issues are formidable political and societal considerations. A detailed analysis, "Wireless Power Transmission via Solar Power Satellite," lists five more challenges:
1. The mismatch between the time horizon for the implementation of SSP and that for the expansion of conventional energy resources 2. The fact that space power is intrinsically global, requiring enterprise models that give every player a suitable stake and adequate safeguards 3. The potential for concerns over reliability, safety and environmental implications 4. The need to obtain publicly-allocated resources outside the normal purview of the energy community 5. The prevailing mind set which tends to view the future energy infrastructure as an extrapolation of the present one.
In light of these challenges to space solar power implementation, the idea is futuristic now just as it was in the 70s. However, it is now technologically feasible and will eventually become more economically viable. Convinced, DK Matai writes: "The question is not whether we harness power from Space; but rather who will get there first to garner first mover advantage with significant impact on global economic competitiveness."