Power of the sun

The world in 2010 is said to be on the brink of a dramatic change in climate.

Environmental group Greenpeace warns that if global temperatures rise more than two degrees Celsius on an annual average, both industrialized and developing nations will be affected in equal measure by the disastrous consequences.

These could include more frequent natural catastrophes, warmer and longer droughts, large-scale crop failures, and a massive loss of biodiversity.

The burning of fossil-based fuels is blamed for global warming. That's why renewable-energy sources could play a role in halting climate change. Experts believe that solar thermal plants, in particular, are a profitable means of generating large amounts of electricity.

Power from the sun

- In 2008, solar power plants generated 286 megawatts of electricity

- By 2011, solar plants are meant to generate up to 1,500 megawatts

- Spain is planning to set up solar plants that will generate around 10,000 gigawatts by 2017

- The German Aerospace Center calculates that by 2025, solar plants in Africa could export up to 60 billion kilowatts of electricity to Europe each year - by 2050, that figure could go up to 700 billion. 

Green role

Solar thermal plants could slash carbon dioxide emissions by around 213 million tons yearly by 2020. That figure could jump to around 4.7 billion tons by 2050. 

Costs

The costs for electricity generated with the help of solar energy depends on the following factors:

- availability of solar resources where the plant is located

- costs of development, financing, construction and operation of the power plant

- conditions for transport and sale

The costs of generating electricity at solar plants in southwestern America and in Egypt are about 20 to 30 percent lower than those in Spain or the North African desert - despite being subject to the same pricing and financing conditions.

That's because direct sunlight levels are up to 30 percent higher. By contrast, solar resources are much more modest in France, Italy and Portugal.

The world's highest sunlight radiation is found in the deserts of southern Africa and Chile. These areas get 3,000 kilowatt hours (kWh) of sunlight radiation per square meter annually.

Producing electricity at a solar thermal power station currently costs between 15 euro cents ($0.19) per kWh at sites that use direct sunlight or "Direct Normal Irradiation" (DNI) to 23 euro cents ($0.29) per kWh at locations receiving lower average sunlight.

In the future, larger concentrated thermal plants, higher production levels, more suppliers, and improvements in technology are expected to drive down costs - to anything between 12 and 16 euro cents per kWh by 2020.

It is estimated that solar energy will get relatively cheaper as prices for conventional fuel rise.  

Author: Martin Schrader (sp)
Editor: Jennifer Abramsohn