Most of Europe's energy supply today is based on fossil fuels. When burning coal, natural gas or oil the green house gas carbon dioxide is being produced, which is the reason for global warming. To protect the climate and save limited resources we will need to introduce an energy supply that does not rely on burning fossil fuels.
The best alternative is the vast use of renewable energies such as solar PV, wind or hydro energies and biomass. They can all be transformed into electricity or heat without emitting green house gases or, like with biomass, emit exactly as much CO2 as they have gathered themselves during their lifetime. Their are globally available and their use is technically mature. Solar PV, wind and hydro energy have been in daily operation for years.
They all have in common their intermittent nature due to fluctuations of wind and solar radiation. This causes problems with the integration of renewable energy sources into existing electricity grids and gets in the way of the large-scale utilization of renewable sources.
One universal storage medium
, though, is hydrogen. It can be produced from all renewable sources and is flexible in use: apart from being easier to integrate into the existing centralised power supply, hydrogen gives renewables access to further segments of the market, namely the decentralised energy supply of homes or the traffic sector where "green" hydrogen as an environmental friendly fuel will play an important role in the future (see figure). The use of hydrogen as an industrial resource is also possible.