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Energy for power hungry Earth
The need for power and energy for our growing population and development is a global concern. Many researchers are considering a number of technologies and sources to fulfil our planet’s ever-increasing demand for power. Over the next 50 years, Earth’s energy demand will be tripled.
The conventional methods for energy production will lead to further global warming. What can be done to solve civilization’s urgent problem for energy? In the November issue of Journal Science, scientists have recommended that humans need to establish space-based power generation systems. In addition, giant sunscreens in space to block out harmful ultraviolet rays, a method known as geo-engineering is also a suggestion in order to stop global warming.
Some of the options they suggest are; developing pollution-free energy, trimming the energy demand itself and intervening in the global warming process through geo-engineering. Experts in atmospheric science and energy production wrote many interesting evaluations and ideas in the report. Also economics and biology from NASA and almost a dozen universities and research institutions including Exxon-Mobil Research and Engineering Company.
Since most of the energy on Earth is provided by fossil fuels, we need to find an alternative as the conversion of these fuels into energy leads to warming of the planet. For many decades now, efforts to use solar power as an energy source have not been as widely beneficial as required. Harnessing the Sun’s energy above the clouds and Earth’s atmosphere, where it is eight times greater, is one way of meeting the world’s energy needs for many centuries according to Martin Hoffert, physics professor at New York University. Hoffert who is also the lead author of the report stated to SPACE.com that, “The potential is vast. From humankind’s point of view most of the Sun’s energy is wasted”. Hoffert’s colleagues have envisioned many options and have recommended continued research into nuclear fusion, and improvements in automobile fuel efficiency. They also consider, in their report, the need for wind and solar power but feel that they would not be sufficient in meeting “baseload” demands. Power plants in space would initially be located in Low Earth Orbit, (LEO). In the area where the space station and space shuttles are situated. Energy would be collected through solar panels, converted to microwave energy and then be beamed to Earth where it would be converted into electric power. Later power plants would be put into higher orbits or even on the Moon. Satellites would also be a good source of transmitting power from one location to another.
The scientist’s state that no single effort would be enough to solve Earth’s problem for increased power or stop global warming but they feel that space-based efforts seem to be more promising.
“We recommend starting in a practical way-with simple, LEO-based systems at relatively low cost, beaming intermittent power to multiple locations and working up to a constellation to handle baseload power”, Said Hoffert. Systems could later on be put in the geo-synchronous orbits from where a single satellite, located above a single point above Earth could beam power to almost half the planet.
The whole idea is a daunting challenge, though. “Space solar power (SSP) is certainly a technological challenge. But much less of one than, say, building a fusion power reactor”, said Hoffert. “We advocate an SP demonstration in the next 10 years to explore the technology and potential for cost reductions aimed at power for developing nations”, he added.
Visual pollution or poetic power?
Though solar energy is a pollution-free source but satellites, each the size of a bus would be reflecting enough sunlight to be seen from Earth. Would they be visibly acceptable is the question? However, a ring of golden satellites in the sun might be quite a poetic inspiration referring to the last line of a poem by William Butler Yeats, “Song of the Wandering Aengus”.
David Criswell, physicist from the University of Houston, another author of the paper, advocates the Moon as a source for gathering solar power. He says, “Prosperity for everyone on Earth requires a sustainable source of electricity.” Researchers say that the raw materials required to make solar sails are already present on the Moon and a lunar station could receive continuous daylight except during a total eclipse when stored energy would be required. At a World Space Congress meeting, Criswell said that a lunar power station could be built in about a decade and begin delivering electricity to a terrestrial grid.
The great sunblock
Global warming needs to be combated and researchers suggest that while there is need to harness the Sun’s energy, ironically, some of it also needs to be blocked. What could be the ideal sunblock or UV protection for a planet’s delicate atmosphere? Giant, translucent shields or mirrors seem to be the answer. “For this application a sunshield or solar parasol would have to be very large (thousands of kilometers in diameter), possible very thin, and possibly fabricated from lunar materials,” says Hoffert. But, he adds, “At this point, space mirrors are more of a thought experiment than a real option.” In order to correct the climate-warming gas production, two per cent of the Sun’s energy would be needed to be blocked. An effort referred to as geo-engineering.
All of these approaches have their deficiencies, the scientists agree and a lot of research and development is required including worldwide cooperation. But before Earth’s power and energy problems become more acute and threaten mankind’s development and progress, compromises will have to be made agree scientists.
The darker side
A nine-month study carried out by the think tank called “Resources for the Future” looked at the market for electricity from now to the next 2 decades till the 2020 a time when experts feel that solar power from satellites might be actually a doable idea. Electric Power Research and Texaco also included their comments. The findings stated various facts. Satellite power is relatively an immature technology as compared to conventional electricity generation in both developed and developing countries. Moreover, launch costs are so high that satellite power is not a cost-effective idea. But nevertheless, NASA should not stop working on the prospect, says Molly Macauley, an economist. She states that “my concern with satellite solar power advocates is that they aren’t looking over their shoulders to realize that technological change and innovation in markets is happening within conventional approaches.”
She adds, “there have been dozens of approaches to building power-beaming satellites. But fundamentally, so long as it costs as much to get to space’ we’ve got a major problem.”
John Mankins, a manager at NASA’s Advanced Concepts states about solar power from space: “The technology to do very large-scale solar power systems that might deliver energy into terrestrial power markets is not at hand. It’s going to take a fair amount of investment and a lot of success in research and development to mature these technologies to make them available.” Another concern is the health risk for humans associated with exposure to magnetic fields, which would be generated by satellite solar power. Until much further research, solar power beamed from space and the visually intriguing “golden apples in the sky” remain a much-wanted technology for researchers.
The writer
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