Why do you need renewable energies?
In the absence of serious political efforts to curb the emission of large quantities of climate-damaging gases worldwide, scientists expect that global temperatures will on average by the end of the 21st century until rise and lead to significant climate change.4) These emissions come mainly from fossil fuels, with which almost global energy supply (Fig. 1). Hard coal and lignite, crude oil and natural gas. When converting these energy carriers into usable energy - in most cases heat - the carbon compounds are burned, producing large amounts of carbon dioxide (), which is considered to be the main cause of the anthropogenic, i.e. the greenhouse effect generated by human activities. It is not only for this reason that there are great efforts in industry and science to develop more environmentally friendly energy sources. In addition, fossil fuels are finite. Due to the increasing subsidies and rising consumption, their prices - and thus also the electricity prices.
In order to limit climate change as much as possible, two approaches seem indispensable: to reduce energy consumption and to rely more on so-called regenerative or renewable energies than on fossil fuels in global energy production. Wind and water power, photovoltaics and solar thermal energy, biomass and biogas in combination with fuel cells, ocean currents and tidal power plants currently appear as promising options for generating energy efficiently without using large quantities to emit.