Scientists say the time is approaching when commercially viable projects based on the concept of beaming solar power back to Earth from satellites in orbit may get off the drawing board.
Solar energy plan no space oddity
Ambitious teams of scientists have long toiled behind the scenes on various missions to space.
But even before they helped put a man on the moon back in 1969, one of their own had concocted another complex plan.
Peter Glaser, who worked with Nasa on numerous experiments carried out in space or on the moon, is credited as the first person to have proposed a method for creating space-based energy that could be beamed back to earth.
He did so back in 1968 and received a patent for his idea five years later. His concept, in short, was to have a satellite that could harness solar energy from the sun, convert it into microwave frequencies and then zap it back as energy to the earth's surface, according to the Institute of Electrical and Electronics Engineers (IEEE), a professional group.
"There it would be collected by special antennas, electronically converted back to low frequencies or direct current, and used to supplement existing earth-bound power plants," says the IEEE.
Currently, the cost to produce electricity is still much more expensive in space than on Earth. It costs about US$100 per kilowatt hour up in space versus about 10 cents down here.
"So if the cost of power in space is 1,000 times higher, how in the world are we ever going to do anything ambitious in space?" says John Mankins, the president of Artemis Innovation Management Solutions, a consultancy that has studied the prospects of space-based solar power.
"There will never be factories or colonies in space, or anything that represents anything ambitious without a lot more energy and a lot lower price," Mr Mankins says.
That is where scientists hope research and development that looks at the prospects of space-based solar power, as well as a bit of lobbying, can come into play.
Many moons ago, Philip Chapman worked as a research scientist alongside Mr Glaser. Mr Chapman is now the chairman for Solar High, a group of senior - and mostly retired - aerospace specialists who formed the group some years back to promote the research and development efforts behind solar powered satellites.
Some of their work has included producing research papers with technical and market information about the state of space-based solar power, which they have shared with policymakers in the US Congress. Others within the group have attended international conferences and discussed the growing need for alternative fuel sources such as this, particularly as the demand for energy around the world rises.
"Several of us in the group were involved in the original study and are still interested," says Mr Chapman.
"It's a clean source of electric power, and if we can build them in a price competitive way we get an extra benefit from them."
Analysts agree there are certain advantages of using solar technology in space versus on earth.
"The appeal is it's more efficient in being able to capture more sunlight in terms of hours of the day," says Michael Barker, a senior analyst with the NPD Group, a market research firm.
One of the issues with trying to tap the sun's rays from earth for power is that they are not always shining — namely at night, or when the sky is overcast.
"So space-based solar power has a significant advantage, because in space if you go to a high enough orbit the sun shines constantly," says Mr Mankins.
But some analysts warn the concept has yet to be proven within the global energy sector, as solar farms have still not been established in space.
"It's not making an impact on the industry currently," Mr Barker says.
"I think that's still in the preliminary investigation stages."
For decades, the concept has struggled to fully take off for a number of reasons.
Back when Mr Glaser, Mr Chapman and others first began discussing a space-based solar power project with interested parties they ran into a macroeconomic challenge: the price of oil moved upward and peaked in the 1980s, only to crash later that same decade, which removed much of the incentive to turn to the sun via expensive satellite projects.
"The whole thing got put on the back burner," says Mr Chapman.
Another hurdle has been the lack of sufficient government or private investments backing a huge space-based solar project.
The industry is still at least four years away from seeing a fleet of solar-grabbing satellites launched into space - from the time that somebody decides to start investing money into such a plan, Mr Chapman estimates.
"It's a big project," says Mr Chapman, who pegs its cost in the tens of billions of dollars. "It's an enormous project."
Others believe the wait will be longer than that.
Mr Mankins, for one, estimates it will take about a decade before there is a major proof of concept for space-based solar satellites. He says advances in robotics, electronics, software and wireless Internet connectivity are playing in the industry's favour.
Only time will tell whether the sun will shine on this ambitious idea.