The Future Belongs to PVs
The Future Belongs to PVs
Photovoltaics (PVs) will certainly not be the only source of renewable energy production in the future, but they are the only source with an almost unlimited technical potential. For example, to replace all fossil fuel used in the world today with hydrogen from PV, electricity-based electrolysis, only some 2% of the world's total desert areas would need to be covered with PV arrays.
Most solar cells use silicon as the primary raw material, which means that the raw material needed is sand (although many chemicals are used in their production). Some solar cells require rare metals, but in such small amounts that it should not be a limiting factor for them.
The first silicon solar cells were produced in 1954. Only four years later the technology went into space-to power satellites. The several-thousand-dollar-per-watt costs were no problem, and since costs plummeted, a plethora of niche markets has evolved.
PV-powered parking meters are increasingly used in France and Germany. Due to the high costs of digging up the asphalt to connect electrical wires, grid kWhs are more expensive than PV kWhs in this case. Even the one-meter extension needed to light a street kiosk with an 11-watt CFL can cost a lot more than a PV module plus battery - if the wiring is to comply with the law.
A lighthouse with PV lighting, one of some 250, outside the Swedish coast
PV module production will continue to grow, bringing prices slowly down and thereby opening new niche markets which will reduce the price even further, until they eventually will become a competitive alternative for power-to-the-grid generation. Production grew 8% per year in 1990-93, 16% in 1994, and 20% in 1995, when the total world production was appr. 80 megawatts peak.
PV systems are now a very competitive billion-dollar industry. Many companies have huge corporations (Canon, Sharp, Honda, and Siemens, to name a few) or governments behind them, in dozens of nations.
Various technologies compete with each other. There are flat, fixed designs, and there are concentrator technologies where the modules move to catch as much sunlight as possible. There are monocrystalline, polycrystalline, and amorphous silicon cells, produced with several different methods. There are non-silicon, thin-film solar cells, such as copper-indium-diselenide and cadmium telluride, as well as tandem, monocrystalline, epitaxially grown cells of gallium arsenide and gallium aluminum phosphide. And then there is the completely different titanium oxide technology.
There is no way to know which companies and technologies will succeed in mass-producing low-cost solar cells. For each of them it is a high-risk venture with huge potential benefits. But it seems unlikely that all of them will fail.
See also:
Overview article on PV Lighting,
Hard Facts on PV Hardware, and
Selected Sources on PV Lighting.
Fredrik Lundberg
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