Solar cells

Solar cells can be the new environmental threat

Solar cells converts sunlight into electricity through the photoelectric effect, which was discovered in 1839. The use of solar cells is perceived as a non-polluting way to produce electricity.

There is hope that the future global energy needs can be met through this technology, without environmental problems, as in the quote from Norwegian Solar Association (10.24.13):

Energiinnstrålingen from the sun to the Earth each year is several thousand times greater than the amount of energy people in the world use and many times greater than Earth's total energy reserves. Solar energy is available over the earth and relatively evenly distributed between countries. In this perspective, solar energy potential to be the major constituent renewable energy source in the future. Use of solar energy based on sustainable and environmentally friendly solutions.

Large solar plants worldwide

There are visions of the construction of large-scale construction of solar panels in sunny parts of the world, including in the Sahara. This has often been linked with optimistic scenarios of a hydrogen society, where electricity from such giant solar plant the reflected transmitted to Europe and used as energy to produce hydrogen gas to display the time fuel cell cars.

The proliferation of solar cells is however very limited at present, and according to the International Energy Agency (IEA) constitute less than one percent of global electricity production. But it is growing rapidly, and the IEA envisages that in 2050, 25 percent of electricity in the world come from solar.

Germany is the country with the largest proportion of electricity from solar cells, with three percent of the country's electricity production from this technology. There it is there painted a glossy picture of solar cells that rescue. Solar, wind and bioenergy will make the country independent of nuclear power while reducing greenhouse gas emissions. In some cities in Germany, including Freiburg, it has become quite common to see residential building with all the south-facing roof side covered with solar panels.

It has not been any significant debate on the adverse environmental impacts of the solar industry. Solar cells have many ways has been portrayed as the most unproblematic form of renewable electricity production.

This picture changes radically when the manufacture of solar cells are taken into consideration.

Solar cells life gives negative environmental impacts

To produce solar panels must first create wafers, which are thin slices of crystalline silicon. Solar Wafers must have the correct structure, and to get what they go through a series of treatments in different kjemikaliebad. Between each treatment, the wafers rinsed in water so that chemical residues do not join to the next bathroom. This is repeated several times and entails very high consumption of water. A medium-sized solar plant (1.4 GW capacity) that perform this process consumes 15,000 liters of water per minute, according Nines Photovoltaics. In addition to the high consumption supplied water through the process steps toxic compounds it is necessary to remove the treatment in separate plants.

The second and perhaps more serious objection by solar production, greenhouse gas emissions. It is partly on emissions of gases heksafluoroetan (C2F6), nitrogentrifluorid (NF3), and sulfur hexafluoride (SF6). These are all extremely powerful greenhouse gases with global oppvarmingdpotensiale (GWP) respectively 9200, 17200, and 39800. GWP is the measure of the gases' effect on atmospheric warming, compared to effect the most common greenhouse gas CO2 has (GWP of CO2 is 1).

Are disadvantaged

With these factors included in the environmental accounts coming solar technology out very badly, with very high greenhouse gas emissions, when compared to other ways of electricity generation. Although the results of different studies vary widely, there is a general feature that solar cells lifecycle involves a significantly greater greenhouse gas emissions than other technologies for transforming renewable energy into electricity.

The methodology of the EU's ExternE about external costs of energy, such as life-cycle emissions from solar installations in Germany estimated at 180 grams of CO2 equivalent per generated kilovatt-hour (kWh).

The figure below shows a comparison with other types of renewable electricity production, emissions in their lifecycle including production, expressed as grams of CO2 equivalent per generated kWh.


The new insight about solar cells environmental impact must be considered in order to contribute to a more nuanced debate and development of renewable energy. Both solar technology and other types of renewable energy are analyzed and discussed in the book "Unintended Impacts of Renewable Energy" published recently published by Springer.