Scientists from around the world will soon gather to discuss how satellites could be used to address the world's energy needs by relaying solar power to Earth. But the U.S. government's decision to abandon research in 2001 could prevent the alternative energy source from ever seeing the light of day.

Solar panels on Earth are inherently limited in their ability to collect energy by two things – the lack of direct sun at night and atmospheric interference from weather. NASA's now-abandoned Space Solar Power program would avoid these terrestrial impediments by launching satellites that would collect solar radiation and beam the energy to Earth. These satellite systems could each provide gigawatts of electricity, enough power for tens of thousands of homes.

Interest in solar space power peaked in 2000, when NASA officials testified before the House Committee on Science that by 2006 test satellites could be wirelessly transmitting energy from space. After three years of studying the challenges and a favorable report from the National Research Council, in 2001 NASA requested and received new funding for the space solar power program. But later that year, NASA canceled the program (the website was last updated in August 2001) and withdrew the funding.

When asked about the decision to pull the plug on the program, former NASA Director Dan Goldin, who resigned his post in November 2001, said in an e-mail that he does not comment on NASA policy issues.

"It was a done deal, the money was there," said Henry Brandhorst, director of space research at Auburn University. Brandhorst said that NASA decided to use the money for the space shuttle and International Space Station programs instead. "It was a policy change."

Without NASA's resources and funding, the technology will never be sufficiently evaluated to determine its true potential, said Brandhorst, who has studied the technology for nearly 30 years. "It must be studied until there are proven to be better options," he said.

Despite this setback, scientists from around the world will gather later this month in Spain to discuss the technology's potential as an energy source on Earth and for space exploration. The Solar Power from Space conference runs from June 30 to July 2, and will include scientists from NASA, the European Space Agency, or ESA, and the Japan Aerospace Exploration Agency, or JAXA.

JAXA and ESA have been spending several million dollars each year researching satellite solar power, but in the United States, scientists volunteer their spare time because there is no public- or private-sector funding. "These are not wild-eyed environmentalists," Brandhorst said. "This is a dedicated community that wants to see something happen."

Brandhorst said satellites in geosynchronous orbits – and always in sunlight – could continuously collect solar radiation and safely beam the energy to Earth as microwaves or through lasers. He said the satellites could be repositioned to deliver energy to receiving stations in multiple locations.

Because there is energy loss during the process of beaming the energy to Earth and converting it back to electricity, it may not be more cost-effective than placing solar panels in places with ample sunlight. However, Brandhorst said the satellites would be most beneficial in providing energy to places that are not easily accessible, do not receive extensive sunlight or do not have sufficient energy-distribution infrastructure.

Brandhorst said that beaming solar power from space is essential for space exploration, which according to President Bush is now NASA's priority. Brandhorst said that it is not feasible to carry enough fuel into space to develop settlements on the moon, so solar energy is the best alternative.

Bush has repeatedly said that the United States must become less reliant on foreign sources of energy as a matter of national security, but his administration has given solar power from space the cold shoulder. While his administration has allocated millions of dollars for research into alternative fuel sources such as nuclear fusion and hydrogen, according to John Mankins, assistant associate administrator of advanced systems at NASA, there has been no funding for space solar power since 2001.

Mankins said that because the technology blurs the lines between governmental agencies, it does not have a true champion. "To NASA, it's not fish, nor fowl, nor red herring – it's not our mission," Mankins said. NASA does not explore terrestrial energy sources, and the Department of Energy does not research satellites, according to Mankins.

"It has fallen neatly through the cracks, as it has for decades," Mankins said. He said that NASA's development of space solar power would likely determine whether or not satellites ever send energy to Earth. "Given how critical NASA is to all the space and related technologies required, it's hard for me to see how it could happen" without NASA.

Arthur P. Smith, a physicist who has written about solar power from space for the American Physical Society (PDF), said that interest in beaming solar power from satellites has waxed and waned since it was first proposed more than 30 years ago. Smith said that research funding was highest during the oil crisis in the Carter administration, but after gas prices retreated the program was shelved for almost 20 years.

Pursuing solar power from space "should be part of our plan for energy independence," Smith said. He said that if NASA invested $10 billion in research over the next 10 years, the technology would likely become cost-effective enough to begin launching satellites.

Neville Marzwell, advanced concepts innovation technology manager at NASA, spent five years researching methods of improving a satellite's ability to collect solar energy before his program was cut. Marzwell claims that politics played a part in the decision to kill the space solar power program.

The United States "doesn't have the political will to fund the research" because of pressure from fossil-fuel lobbyists, Marzwell said. "We could have become the Saudi Arabia of the world electricity market," Marzwell said. But because the coal and oil industries don't want threats to their profits, they applied political pressure, causing the program to be scrapped, according to Marzwell.

Auburn's Brandhorst hopes that NASA's emphasis on sending astronauts to Mars will lead to renewed interest in space solar power. "For a time, exploration was a bad word at NASA. Now it's a mandate," Brandhorst said, and the program should receive money because it "has clear repercussions for exploration."