Already back in 2000, the German federal government decided to set a time limit for the use of nuclear power, subsequently often referred to as a ‘transitional technology’. This means that – dependent on economic aspects, reactor safety and the development of renewable energy – nuclear would gradually be phased out.
In September 2010, the German federal government adopted the ‘Energy Concept’, a comprehensive strategy that called for the replacement of conventional energy sources by renewables by the year 2050. It covers the challenges of the energy efficiency of buildings, infrastructure and energy research as well as issues related to electricity trading.
In March 2011, the reactor catastrophe in Fukushima caused worldwide alarm and prompted the German federal government to further tighten the legislation. This resulted in the socalled ‘Energy Transition’: This collection of resolutions and draft legislation not only called for an earlier phase-out of nuclear energy, but also gave a specific timetable for measures to expand alternative energy sources.
Current consumption in Germany is estimated to be approx. 600 million megawatt hours per year. Of this, industry, trade and commerce account for some 44 percent, transport for 28 percent, and households and other properties for the remaining 28 percent. Some 80 percent of the base load is currently generated from conventional sources, that is nuclear, coal, oil and gas.
Reduction of consumption
» The energy transition cannot be achieved without a drastic reduction of energy.
The first step in the energy transition is the reduction of energy consumption. The energy efficiency of buildings – which use some 40 percent of total energy – can be greatly improved by such measures as effective facade insulation, the use of geothermal, intelligent building services equipment, and efficient lighting. Drees & Sommer is a leader in this area with innovative concepts for both new and established buildings.
There is also considerable savings potential in industry: Energy-saving motors and intelligent control systems allow the consumption of electric motors to be reduced by up to 60 percent. Energy monitoring cuts the energy required for air conditioning of industrial buildings by 20 percent and more.
» A safe energy supply requires a sensible mix of energy sources.
For Germany, wind power from wind farms is the most important renewable. Future innovations will make the kilowatt hour from a wind turbine as cheap as from coal. But like generation from photovoltaics, energy generation from wind fluctuates with the weather and is not demand-driven. For this reason, these technologies will have to be supplemented by combined cycle gas turbines (CCGTs) and cogeneration units. Swarm intelligence is also increasing in importance. In this case, it can be applied to the consolidation and control of numerous privately owned small power generators (cogeneration units, hydro, wind turbines).
» Energy storage facilities will have to be able to partially balance out the fluctuating supply from renewables.
Fluctuating energy supply from renewables means that facilities are required that can store excess energy for hours, days and even weeks if necessary. Such excess electricity can, for example, be used in electrolysis plants to produce environmentally friendly hydrogen. This can be fed into the natural gas network, stored underground, used in fuel cells, or converted into fuel.
» The intelligent interaction of central and decentralized energy generation will require intelligent networks.
High-tension DC power transmission allows power to be transmitted to consumers without significant losses. On the other hand, consumers will be generating ever more power themselves: 15 years ago, only a few hundred suppliers fed electricity into the German grid. In future, millions will be generating electricity with PV, wind turbines, biomass plants, and small cogeneration units. This trend – combined with the fluctuating supply from renewables – will require smart grids that can balance generation and consumption.
If Germany is to achieve its goal of generating some 50 percent of electricity from renewables by 2030 – and 80 percent by 2050 – the proposed courses of action will have to be closely coordinated. Organizing this process as an element of the national economy is the role of government – as is securing finance for the necessary grid expansion. Transregional power transmission lines as well as regional and local distribution networks will have to undergo a massive upgrade to be in a position to handle the growing amount of decentrally generated green electricity. The current subsidies for green energy will have to be adjusted in proportion to their contribution to overall power supply.
On the other hand, industry must ensure that renewables become competitive. This will require a fundamental change in subsidy policy and of the (German) Renewable Energy Act.
When related to the energy transition, ‘the blue way’ means subordinating individual interests to a goal-focused common process, whereby goals are regularly reviewed and, if necessary, optimized during the course of the process. Rigid adherence to existing rules and guidelines will not lead to success.