2010.12.02

Sustainability

A temporal unlimited energy supply can be ensured by regenerative energy carriers, only, But which concepts are in fact sustainable?

Limited resources of fossile and nuclear energy carriers set up the horizon of coverage for today's majorly used technologies like thermal power plants and combustion engines to approximately 50-150 years for crude oil, natural gas, uranium and coal, respectively.

By a lifetime expectancy of further more 5 billion years the sun provides for an unequal longterm alternative, resulting in terms of human timescales for infinte supply. As a matter of principle, technologies relying direct or indirect to impact of solar irradiation provide for the potencial of sustainable energy supply. Beside solar technologies like photovoltaic and solar thermal the sun acts as "motor" of all winds, as "carrier" for water up to the mountains - which may be used for hydro power on its way downhill - ans as main energy source for all herbal life. Thus, a large variety of different kind of natural resources evolves, which already today contributes to global energy supply.

Here, an exemplary view shall be taken on a very recent technology from photovoltaics to engross the thought of sustainability. In detail this relates to the wide range of thinfilm technologies, many of them showing a more  or less early development phase. It is obvious that research focuses on high efficiency for reasons of future yield. But conditions of minor impact in an early development phase may become an obstacle for mass production: Materials of so called noble earths, which are globally provided only in very rare amounts. A global race of competition to obtain these resources already has started. Dimensions may become more illustrative by the following example. In 2010 in Germany, there will be an amount of photovoltaic modules from different technologies newly installed on buildings and plain ground, which covers in total an area of approximately 100 square kilometers - an area to be compared to a town of 100,000 inhabitants. For this reason it is in question if these thinfilm solar cells comprising indium or tellurium will play a significant role in strong growing future markets.

In the sense of sustainability, the use of abundant materials which are on a quantity basis not subject to such tight restrictions would be more consistent. In addition, this kind of a solution will provide for longterm econonics as well: Indium already reaches a price level to be compared to gold.