The Holy Grail has always been the stuff of legend and exactly what it might be the subject of intense debate for centuries. In today’s society, realism dictates that the grail we seek now needs to be that which will ensure the survival of humanity on this planet. As populations grow and fossil fuels are depleted, surely the prize we now seek is an alternative form of energy, preferably very cheap or even free? Yet the answer has been shining down upon us for billions of years.
Europe’s first commercial concentrating Planta Sol 10 solar power tower operates near the Southern Spanish city of Seville . The 11 megawatt (MW) solar tower station produces electricity with 624 large movable mirrors called heliostats.
Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind, wave power and others, account for most of the available renewable energy on earth. Only a minuscule fraction of the available solar energy is used though solar energy’s uses are limited only by human ingenuity. To harvest the solar energy, the most common way is through solar panels.
An Israeli company and a Californian one are making solar power history: Southern California Edison (SCE) and BrightSource Energy from Israel are embarking on the world’s biggest solar energy project. When the contracts are fulfilled, as early as 2013, the sun project could power almost 1 million California homes.
Solar technologies are broadly characterized as either passive or active depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the sun, selecting materials with favorable thermal mass or light dispersing properties and designing spaces that naturally circulate air.
Waldpolenz Solar Park, the world’s largest thin-film photovoltaic power system, was built by German developer and operator JUWI at a former military air base to the east of Leipzig in Germany. The power plant is a 40 MW solar power system using state-of-the-art technology and was fully operational by the end of 2008.
Total solar energy absorbed by earth’s atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year. In 2002, this was more energy in one hour than the entire world used in one year. Photosynthesis captures approximately 3,000 EJ per year in biomass. The amount of solar energy reaching the surface of the planet is so vast that in one year, it is about twice as much as will ever be obtained from all of the earth’s non-renewable resources of coal, oil, natural gas and mined uranium combined. It has been estimated that we would need to capture only one millionth of one per cent of solar output to supply all the needs the earth might ever have. Solar energy is truly versatile.
The solar-electric Helios Prototype flying wing is shown over the Pacific Ocean during its first test flight on solar power from the U.S. Navy’s Pacific Missile Range Facility on Kauai, Hawaii, July 14, 2001.
The global demand for energy continues to grow. In 2005, electric power plants produced 17,000 terawatt-hours; by 2030, global projections predict nearly double that at 33,000 terawatt-hours. For perspective, a single terawatt-hour can power about 90,600 homes for an entire year. It takes 15 terawatt-hours to power Chicago each year. Solar power can also solve our transport problems in time, and solar cars are nothing new.
Australia hosts the World Solar Challenge where solar cars like the Nuna3 race through a 3,021 km (1,877 mi) course from Darwin to Adelaide.
Cool Earth have invented a solar power balloon that collects concentrated solar energy that is many times more powerful than has been collected before. California-based Cool Earth Solar claim the ability to cheaply harvest solar energy in gigawatts of power. Instead of using flat solar panels, they use what are basically large balloons as concentrators.
Each balloon is about 8 feet tall and is made of thin plastic film. It has a transparent upper hemisphere and a reflective lower hemisphere that form a shape that naturally focuses sunlight on a photovoltaic cell. The beauty of this is that it is a simple idea and needs no new technology. But it will generate 300-400 times the electricity that same cell could produce without the concentrator. Now that IS efficiency.
Nells Solar Power Plant is the largest of its kind in the USA.
There is an ever accelerating demand for moving away from traditional energy sources, and there are many schemes worldwide both in the construction and the planning stages. Alternative energy generation is now a top priority with governments and every avenue is being explored. Wind farms make use of an abundant natural resource, as do coastal plants that harness the power of the waves, yet still we do not produce enough ‘green’ energy. Happily, this situation is changing, and technological advances may just allow us to finally grasp that Holy Grail of boundless free energy within the foreseeable future. Let us pray fervently that we are not too late.