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Sonnenenergie (Source: Reicher)
Image: Reicher / Fotolia

99 percent of solar energy remains idle

July 16, 2012

At the Nobel Prize convention in Lindau scientists discussed future energy sources. Due to its’ inefficiency bio fuel suffered from poor results.


The climate change necessitates the end of an age in which fossil fuels make up the majority of energy sources; in the prevention of further heating up the atmosphere through carbon dioxide (CO2). The combustion of plants was long seen as a prospect alternative to fossil fuels, however bio fuels not only have a severe carbon footprint, furthermore they are highly inefficient. “Therefore the production of bio fuels is one of the dumbest things out there”, says Nobel Prize winner Hartmut Michel at the 62nd Nobel Prize convention in Lindau.

Deutschland Lindauer Nobelpreisträgertagung Hartmut Michel
Nobel Prize winner Hartmut MichelImage: DW/G.Hamann

Although this year’s convention revolved around physics, biochemist Michel’s expertise lies within the field of power generation in plants. He discovered the structure, contained in several bacteria, and plants, which converts sunlight into chemical energy. Thereby plants are highly inefficient, says Michel. “De facto the plant only saves less than one percent of the solar power, in biomass.” Solely, the energy that the plants save in biomass is at disposal as fuel. As a result more that 99 percent of solar energy remains idle, in the usage of bio mass as fuel.

Source: dpa
Bio fuel - highly controversialImage: PA/dpa

Therefore Michel believes that the land area can be used more sufficiently, than through the cultivation of plants for bio fuels. On one hand we warrant the land for production of groceries for the ever growing population. On the other hand alternative cultivation would profit the climate. Reforestation, instead of exploiting the land area, for the production of bio fuel, would save ten times as much CO2, Michel asserts. Water would also be saved, “According to several reports one litre German Biodiesel requires 16,000 litres water.”

The Nobel Prize winner sees the cars of the future driving with electro motors, which gain their energy from sunlight through photovoltaic cells. Photovoltaic cells are clearly more efficient than plant cells; they are able to salvage 15 to 20 percent of solar energy. In addition a car running on solar energy, would consume only 0,2 percent of the land area for energy extraction, in order for it to run on biodiesel.

03.2012 DW Highlights März Die leise Revolution (Elektroauto)
Electro motors: highly effective

According to the scientist, “photovoltaic cells in combination with an electro powered motor would prove 400 times more efficient than the combination of biomass, bio fuel, and a combustion motor.“

Needless to say it would require an extremely powerful battery. “such batteries are not completely unattainable. Scientists are working on promising tin-sulphur- lithium- batteries”, said Michel. These are ten times more powerful than ordinary lithium-batteries.

Pflanzen im Nährmedium. Quelle: www.transgen.de Copyright: Bundesverband Deutscher Pflanzenzüchter e.V.
Genetically modified plantsImage: Bundesverband Deutscher Pflanzenzüchter e.V.

Lastly, this technology is also dependent on the present possibilities of storing generated energy – the most present problem in all types of renewable energy. Fossil energies are currently unbeatable, measured by their convenience, in regards to transportation and energy amount per mass unit. The scientists discussed several approaches to solve the energy supply and storage of renewable energy at the final podium of this years Nobel Prize winner convention.

Michel himself wants to take a approach in his fight against the climate change; through genetic engineering he is aiming to fully exhaust nature’s potential. In the process of photosynthesis plants absorb CO2 from the atmosphere. He believes, “the efficiency of carbon dioxide fixation could allow for an increase by 100 percent.”

However, genetic engineering can serve multiple causes, optimizing the usage of photosynthesis to increase its’ efficiency. So far plants can only process less than half of the sunlight in photosynthesis, to fixate CO2.The modification of plants, could optimize the usage of a greater light spectrum. “In that case, the leaves would be black instead of green. I’m not sure, if people would like that.”

By Gianna Grün

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