Recently, this article on CNN.com revisits the idea of collecting solar power in space and beaming it down to Earth. With such a large world demand for energy expected in the next 20 to 50 years, and declining costs for access to space, could this be the time for this science fiction technology to become a reality? As our costs continue to increase, geographically sourced resources are seen as unstable, unpalatable, or insufficient, this idea may finally have come of age. As the article states, this idea of constructing large solar power collection facilities in space and beaming the energy back to Earth via microwaves or lasers or other means has been floating around since the 1960s. While from the beginning we have had the technology to do this kind of thing, the costs were just too high for this kind of system to compete with ground-based electric utilities. The question we have now is has that equation changed sufficiently to make these power stations a reality.
Benefits
The reason for constructing solar power in space versus on the ground is that you turn what would be a periodic power source with a roughly 12 hour on/off cycle into a nearly constant power source that also never has to worry about clouds or other weather or even air decreasing the amount of sunlight. So, you get more than 200% of the power out of the same hardware than you would on the ground. Also, the normal benefits of solar power apply as well: it is pollution free during operation, and it is not dependent on the provision of fuel through international trade and the economic and political volatility that sometimes creates. [ad name="Adsense Small Horz Banner"] Costs
The costs of this approach have been reducing steadily since the 1960s. Solar power technology has become much more efficient (meaning less mass would have to be launched into space) and much less expensive. Even greater increases in efficiency and cost effectiveness are likely in the next decade. The most significant cost, however, is access to space, specifically geosynchronous orbit. These costs have not changed much in the past 20 years, although that, too, could be changing with the increase in private competition occurring in this industry. Given the challenges, however, I would not expect a significant private capability to access high orbits for the next 20 years. That area will remain primarily government funded and relatively expensive. But, given the improvements in solar technology, launch costs for a given amount of power capacity are decreasing.
Leapfrog
Leapfrogging refers to the tendency of developing economies to take the next best available technology off the shelf as they add infrastructure, which many times causes those economies to end up with higher technology infrastructure than established developed economies have. So, could space solar power be one of those technologies, shunned by the developed West and taken up by developing India and China. The CNN article brings up that possibility. With enormous costs to electrify their nations from a minimal starting point, India and China can consider this technology from a clean slate perspective. Given soaring fuel costs for all energy types around the world, this strategy may prove to be an excellent long term move. With a steady source of energy totally independent from most Earthly politics, and any pressures on the supply side, they may have a real recipe for sustainable long term energy development.