August 13th, 2020
The renewable energy resource which at present is the least developed is geothermal heat. Deep-well geothermal energy makes use either of hot water from the depths of the earth, or it utilizes hydraulic stimulation to inject water into hot, dry rock strata (hot-dry rock process), with wells of up to 5 km deep (see the chapter “Energy from the Depths”). At temperatures over 100 °C, electric power can also be produced – in Germany for example at the Neustadt – Glewe site in Mecklenburg-Vorpommern. Favorable regions with high thermal gradients are in particular the North German Plain, the North Alpine Molasse Basin, and the Upper Rhine Graben.
Geothermal heat has the advantage that it is available around the clock. Nevertheless, the use of geothermal heat and power production is still in its infancy. Especially the exploitation of deep-well geothermal energy is technically challenging and still requires intense research and development. Near-surface geothermal energy is more highly developed; heat pumps have long been in use.
The exploitation of deep-well and near-surface geothermal heat more than tripled in the decade from 2000 (1.7 TWh) to 2010 (5.6 TWh). If and when it becomes possible to utilize geothermal energy on a major scale, then its constancy and reliability will make a considerable contribution to the overall energy supply. Its long-term potential in Germany is estimated to be 90 TWh/year for electric power generation and 300 TWh/year for heating.
The Window of Opportunity
How will energy supplies in Germany develop in the future? Will all the renewable energy source options play a role, and if so, to what extent? The resolution of the federal government on June 6, 2011 contains the following elements for an energy turnaround in Germany:
• An exit strategy for nuclear power in Germany by the end of 2022;
• Continuous development of the use of renewable energy sources;
• Modernization and further development of the electric power grid;
• Energy conservation and an increase in efficiency in all areas concerning energy;
• Attaining the challenging climate protection goals and thereby a clear-cut reduction in the consumption of fossil fuels.
The German Federal government, with its energy turnaround (Energiewende) package adopted on June 6th, 2011 and the amendment of the Renewable Energy Act, is pursuing the goals set out here: The fraction of renewable energy sources in electric power generation are to increase as follows:
– by 2020 at the latest up to at least 35 %
– by 2030 at the latest: up to at least 50 %
– by 2040 at the latest: up to at least 65 %
– by 2050 at the latest: up to at least 80 %
The goals for growth of the fraction of renewable energy sources in overall energy consumption (electric power, heating/cooling, transportation) are:
ful effects on the climate, the beneficial aspects of renewable energy sources will presumably become more and more apparent .