Did you know that all the fossil fuel that can be extracted from the Earth is only equivalent to 20 days of sunshine? In fact, according to the Union of Concerned Scientists, the amount of sunshine that falls over the entire Earth’s surface, averaged over 365 days, is equivalent to 4.2 kilowatts of energy per day.
Research on solar energy began as early as the 1860’s but died down by the turn of the 20th century with increasing investments in fossil fuel. The biggest impetus to solar power research came as late as 1973, with the oil embargo. The US government allocated $400 million per year for solar energy research in 1973, from a mere $1 million in the previous years. The next big push to solar power research came in 1997, with the Kyoto Protocol bringing to light the dangers of greenhouse emissions all over the world.
Photovoltaics has seen average production growth of 40% per year since 2000, with installed capacity equaling 10.6 GW by the end of 2007, according to the Renewables 2007 Global Status Report by Worldwatch Institute. In fact, today it is more economical for commercial systems to install photovoltaics for free along with a long-term power purchase agreement.
The applications of solar power are limitless. Some of the more common areas that use solar power today include:
Despite being an inexhaustible source of clean energy, solar power also has some disadvantages:
Solar power technology today is left to grapple with an even larger question – what does one do when the sun sets?
Regardless of the drawbacks and hurdles present today, solar energy remains one of the most viable alternatives to the fast depleting fossil fuels and the rapid rise in greenhouse emissions.