The potential power production by wind energy plants installed in Germany until 30 June 2010 amounts to about 47.9 bn kWh (according to the German Wind Energy Institute, dewi), and rising. An increasing extension of wind power is expected for the future in order to reach the politically designated climate protection targets. Basing on the recent "Leitstudie 2010" (Scenario A) of the Federal Environment Ministry, wind energy output will contribute with about 182 bn kWh (261 bn kWh) in the year 2030 (2050). The highest growth contribution is expected to come from repowering of old assets as well as the exploitation of offshore potentials. So the geographical distance between electricity production by wind energy (mainly in the northern part of Germany and offshore) and energy demand (mainly in NRW and southern parts of Germany) is expected to expand. Thus the key question is to find the most suitable technologies and structural measures to keep the balance between supply and demand.

Against this background the following central questions are to be answered:

• To which amount (level, frequency as well as temporarily and geographical allocation) an excess of wind energy output in Germany is to be expected up to the year 2030 (forecast up to 2050)?
• What will be the consequences of this process for the electrical energy system (especially for the power grid)?
• Which solutions are available (when and to which extent) for the future handling of a high proportion of wind power production and even production excess?
• Compared to a growing feed-in of accumulator-, reconciliation- and regulating options (e.g. hydrogen), which specific advantages and disadvantages can be expected, focusing only on a keen electricity based view?
• What will be the anticipated appraisements of the three sustainability dimensions ecology, economy and society?
• Which strategies can consequently be derived for a sustainable handling of wind energy excesses?
• Which unsolved questions arise or exist concerning a sustainable handling of wind energy excesses?