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Giant orbiting power plants

Harvesting the sun’s abundant energy from space could provide a cost-effective way to meet the world’s power needs, a group of international scientists have said.

Orbiting power plants capable of collecting solar energy and beaming it to Earth appear ‘technically feasible’ within a decade or two based on technologies now in the laboratory, it has been claimed.

Such a project may be able to achieve economic viability in 30 years or less.

Plan for the future: An orbiting power plant similar to this with giant solar panels could be used to harvest the sun’s energy and send it back to earth
‘It is clear that solar power delivered from space could play a tremendously important role in meeting the global need for energy during the 21st Century,’  a study group of the Paris-headquartered International Academy of Astronautics said.

The study, which was led by John Mankins, a 25-year Nasa veteran and the U.S. space agency’s former head of concepts, was billed as the first international assessment of potential ways of collecting solar energy in space and delivering it to Earth via wireless power transmission.

The study said government money would probably be needed to get the concept, known as space solar power, to market.

Private-sector funding is unlikely to proceed alone because of the ‘economic uncertainties’ of the development, it said.

But the study said that both governments and the private sector should fund research to pin down the economic viability of the concept, amid concerns about humankind’s continuing reliance on finite fossil fuels that contribute to global pollution.

An estimate of the potential overall price tag for completing the project was not given.

Ambitious: Each of the solar-powered satellites would be as wide as several kilometers across and the spacecraft would collect sunlight up to 24 hours a day

Some scientists believe that space solar power is a potential long-term energy solution for Earth.

The idea is to put first one, then a few, and later scores of solar-powered satellites in orbit over the equator.

Each will be as wide as several kilometers across and the spacecraft would collect sunlight up to 24 hours a day.

This is compared with surface panels now used to turn sunlight into electricity which collect half of that at most.

The power would be converted to electricity on-board the spacecraft and sent to wherever it is needed on Earth by a large microwave-transmitting antenna or by lasers, then fed into a power grid.

Skeptics deem the concept a non-starter, at least until the cost of putting a commercial power plant into orbit drops dramatically.

Impressive: A close-up shot of how one of the giant solar-panels could look

Other hurdles include space debris, a lack of focused market studies and high development costs.

The study, conducted from 2008 to 2010 then subjected to peer review, found that the commercial case had substantially improved during the past decade, partly as a result of government incentives for nonpolluting ‘green’ energy systems.

A pilot project to demonstrate the technology even as big as the 400-tonne International Space Station could go ahead using low-cost expendable launch vehicles being developed for other space markets, Mr Mankins said.

Ultimately, tens of billions of dollars would be needed to develop and deploy a sufficiently low-cost fleet of reusable, earth-to-orbit vehicles to launch full-scale commercial solar power satellites, the study group estimated.

The group said the necessary research and development work should be undertaken by countries and organisations in concert, including space agencies, companies, universities and nongovernmental organisations.

Power source: Scientists believe that harvesting the sun’s energy from space could meet the world’s power needs

International interest in the concept has grown during the past decade, spurred in part by fears that in coming decades global production of petroleum and possibly other fossil fuels will peak and start to decline.

Adding to a quest for new energy sources are projected jumps in worldwide per capita demand for energy to fuel economic development and concern over the accumulation in Earth’s atmosphere of fossil fuel-derived greenhouse gases.

The idea of harnessing solar power in space has been studied off and on for 40 years, including by the U.S. Energy Department and Nasa.

U.S. and Indian business, policy and national security analysts in September called for a joint U.S.-Indian feasibility study on a cooperative program to develop space-based solar power with a goal of fielding a commercially viable capability within two decades.

The study group, co-sponsored by the Council on Foreign Relations think tank and Aspen Institute India, included former U.S. Director of National Intelligence Dennis Blair and Naresh Chandra, a former Indian ambassador to the United States.

Colonel Michael Smith, the U.S. Air Force’s chief futurist as director of the Center for Strategy and Technology at Maxwell Air Force Base in Alabama, said the idea has the potential to send safe, clean electrical energy worldwide ‘if we can make it work.’

‘Isn’t that what government and industry should be working to do?’ he said.