Tapping into the sun’s energy

Schott

As the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) indicates, climate change has accelerated over recent decades and man-made greenhouse gases have been proven to have a considerable impact on the process. We need to question our energy use and how production and infrastructure need to change drastically. Only regenerative energies will enable us meet the challenge.

Several nations are now making alternatives to the conventional energy mix available. In Germany, the regenerative proportion of generated electricity is around 12% – with a distinct upwards trend. Reliable studies show that, by 2030, it will be possible to produce nearly half of the electricity required with renewables. With a global energy network, a so-called supergrid, supply and demand can be aligned better: the North African midday sun, for example, could deliver the electricity needed to light up Sydney in Australia in the evening.

The sun is a power plant and delivers 2,500 times the energy currently used globally. Even though it contributes little usable energy at the present time, it is the most important regenerative source of a future, environmentally sound, sustainable power supply.

SCHOTT began to focus on solar power early and is now one of the sector’s leading companies on CO2-free energy solutions. With over 40 locations worldwide, it serves regional infrastructure needs with photovoltaics and solar thermal power components.

A future market on the move

The solar economy will not be able to reduce its production costs without consistent growth. However, decreasing costs and increasing effectiveness mean that solar power is now able to compete with other energy sources. Political programmes against climate change have further strengthened the motivation to use renewable energy.

In its 2003 annual report, the German Advisory Council on Global Change (WBGU) acknowledges that, by 2040, the sun will be the most important renewable energy source. In 100 years’ time, 70% of all energy demands will be covered by solar power – one half by photovoltaics (PV), the other by solar thermal power. To achieve this, SCHOTT is now working on high-quality, efficient solutions and is the only company to offer both these technologies.

PV Solar is a SCHOTT technology that captures the power of the sun for use not only in calculators, roof top solar panels, but also in such advanced solutions as the power supply of satellites. As a decentralised technology, photovoltaics also delivers adequate energy supplies to regions that are barely, or not at all, connected to the grid.

Electricity is the basis of development and the sun is free of charge. With PV solar power, around two billion people will now be able to take advantage of light, communication, education and healthcare. Developing countries can boost their economies without having to build ramified energy networks. “Off-grid” rural areas can be provided with electricity and local infrastructure developed. Even in developed countries, there are solutions that have been specifically designed to serve secluded industrial plants or telecommunication facilities.

Bundling energy

Solar thermal power is another pillar of a successful energy turnaround and especially suited for central electricity generation. Regions with an abundance of direct sunshine can produce electricity on a large scale. Plants in the United States have proved for more than 15 years that they are practical and marketable. In southern Europe, solar thermal power stations also operate very efficiently.

Most notably, solar technologies have the highest effectiveness and lowest costs per generated electricity unit. Particularly power plants that use mirrors, so-called parabolic trough concentrators, collect the sun and transfer the bundled heat to a heat-carrying oil to drive steam turbines in the power station.

Solar thermal power plants are suited for industrial usage with power capacities of up to 200 MW. They already produce electricity for peak loads at competitive prices and in a few years will do this for basic loads as well. Depending on the sun’s intensity, the cost per kW-hour varies between 10 and 20 euro cents.

The first solar thermal trough power plant built in Nevada in 15 years, Nevada Solar One, will supply electricity to 40,000 households. More than 19,000 SCHOTT solar receivers form the heart of the 64-MW power station. This will eliminate the production of harmful greenhouse gases approximately equivalent to the emissions of one million cars. The first commercially used solar thermal plant in Europe, AndaSol, is currently being built in Spain, also using SCHOTT technology, and will supply 150,000 people with electricity. Solar thermal trough power plants are about to make their breakthrough. They are the ideal solution for central power supply. A modern highvoltage continuous current can transfer the generated electricity cost-effectively and without loss to supply less sunny regions. Technically approved solutions have already been used for years in China and the US.

A sustainable mix of energies, which is profitable, reliable and climate-friendly, is urgently needed. Solar energy is the key. The two technologies of photovoltaics and solar thermal power serve the different needs, work efficiently and are CO2-free. That is what SCHOTT is researching and working for.

W: www.schott.com