GERMANY—If there was a way for us to harness the full energy of the sun, we wouldn’t be experiencing any crisis in energy. The Earth receives 174 petawatts of incoming solar radiation at the upper atmosphere. Approximately 30 percent is reflected back to space, while the rest is absorbed by clouds, oceans and land masses.

The total solar energy absorbed by Earth’s atmosphere, oceans and land masses is approximately 3,850,000 exajoules  per year.  In 2002 this was more energy in one hour than the world used in one year. 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 nonrenewable resources of coal, oil, natural gas and mined uranium combined. Sadly, we only use a miniscule fraction of the available solar energy.

Although efforts to harness power from the sun have started during the so-called Industrial Revolution in the 1800s, the idea never really caught on. During those times, the supply of fossil fuels was presumed to be endless and there were only a few people who were concerned of the future once these nonrenewable sources have been exhausted.

These days, however, there is a renewed focus as more and more people see the advantages of solar energy. Solar technologies have become more and more affordable and even governments across the world are offering financial assistance. Solar electric systems are now used to power many homes, businesses, holiday cottages and even remote islands in the Philippines. Solar cells are powering anything from household appliances to cars.

Solar cells are becoming increasingly cost-effective as more distributors enter the market and new technologies continue to offer more choice and new products.

Germany is the world’s top photovoltaics (PV) installer, which accounts for almost half of the global solar-power market. The country has a feed-in tariff system for renewable power, which requires utilities to pay customers a guaranteed rate for any solar power they feed into the grid.

Germans installed about 1,300 megawatts (MW) of new PV capacity in 2007, up from 850 MW in 2006, for a cumulative total exceeding 3,830 MW. Germany added a further 2 gigawatts (GW) in 2008 and 2.5 GW in 2009, taking the total to 8.3 GW by end of 2009.

As capacity has risen, installed PV system costs have been cut in half between 1997 and 2007. Solar power now meets about 1 percent of Germany’s electricity demand, a share that some market analysts expect could reach 25 percent by 2050.

Solar power is traditionally used for solar lighting, greenhouses, water heating, space heating, space cooling, process heat generation, cooking, water distillation and disinfection. However, it is in electrical generation where solar energy has economical impact. PV has mainly been used to power small- and medium-sized applications, from a single solar cell to photovoltaic arrays. Multimegawatt PV plants are becoming common in the United States and Europe. As an intermittent power source, solar power requires a backup supply, which can be complemented with wind power.

In Germany Q-Cells, Jurlich and Juwi are leading companies in the field of solar technology.

Established in 1999, Q-Cells is the world’s largest manufacturer of PV cells. Its core business is the development, production and marketing of high-quality (mono- and multi-) crystalline silicon PV cells.  Oliver Beckel, head of international and strategic projects, told the BusinessMirror that the main objective of the company is to drive down the costs of photovoltaics quickly and permanently. “After all, this is the only way to make solar power affordable and competitive.”

Q-Cells has manufacturing facilities in Bitterfeld-Wolfen in Saxony-Anhalt in Germany and in Selangor, Malaysia. The company has developed the performance of its PV cells, as well as its technological production processes. It is also developing additional important technologies through partnerships for the commercialization of these technologies. Markets being considered by the company are in China, the US, Asia, Africa and the Middle East.

Beckel said these technological processes are already realizable; “it’s just a question of will and cost.” At present, the cost of putting up PV plants is still relatively more expensive than fossil-fired facilities. He, however, expects “cost to improve in five to seven years.”

Beckel said it is possible to put up a 10-megawatt PV facility in just one month. “However, financing is the main issue.”

Over at Forschungszentrum Jülich, Dr. Thilo Kilper, project manager of the Institute of Energy Research, said the scientists have developed a thin-film photovoltaic cell which requires much les silicon than previous ones. When before solar cells contain high-grade (and high-priced) monocrystalline silicon, Jurlich adds a third silicon layer. The third layer contains a germanium alloy which enables better use of captured light. The solar cells are adapted in line with the different wavelengths in the solar spectrum.

These thin-film solar cells can now be applied to large areas of glass or even flexible foils and metals, Kilper said, thus opening up new possibilities for architects and building owners. In the future, he said, it is even possible to generate solar power on curved areas—thus reducing the need for space requirements in solar fields.

Juwi solar develops, finances, builds and operates solar power plants of any size, both in Germany and overseas. In the last 10 years, the company has gathered experience with more than 1,200 photovoltaic projects (with a total capacity: more than 400 MW) on rooftops and in free-field installations. Among its numerous projects are the 40-MW PV power plant in Walpolenz, Germany; the 2-MW PV facility in El Cura, Spain; the 53-MW solar-power plant “Lieberose” near Cottbus, Germany; and the impressive 1-MW plant in Verona, Italy, which sits on top of a sports arena.

All the representatives of the three German companies agree that the challenge for the PV industry these days is on energy storage. Solar energy is not available at night, and energy storage is an important issue because modern energy systems usually assume continuous availability of energy. Traditionally, rechargeable batteries are used to store excess electricity. But these cannot be used when talking about hundreds of megawatts in production.

Experts are also recommending pumped-storage hydroelectricity. Energy is stored in the form of water pumped when energy is available from a lower elevation reservoir to a higher elevation one. The energy is recovered when demand is high by releasing the water to run through a hydroelectric power generator. Some companies are also pushing solar energy in combination with wind power.

One thing is clear, solar cells are becoming increasingly cost-effective as more distributors enter the market and new technologies continue to offer more choice and new products.