Abstract:
Energy from wind
Hermann-Josef Wagner, Professor, Ruhr-Universität Bochum
Wind energy will provide a major share of our future energy supply, and, due to the possibility of going offshore, it has an immense additional potential for power supply. In some studies has been estimated that wind power could supply up to one third of the world’s electricity by 2050. Wind energy has also very good prospects in northern Europe. The rated power of wind converters at the end of the year 2008 has been about 120 GW worldwide; the half of them was installed in Europe. But also less industrialised countries like China and India are on the way. The potential of wind energy onshore, with the exception of repowering, has been nearly exhausted in some countries, e.g. Germany, so that future projects will have to go offshore. Due to the economics of scale this will require the rapid development of wind converters of the 3-6 MW-class in good technical quality; moreover, grid expansion must have been accomplished by that time. Technical problems seem to be solvable by now. A huge palette of foundations is constructed, and also first turbines are tested near shore. Another major problem is the financing status in the last years. A lot of projects got the permissions for accomplishment, but the installations did not happened on time.
Wind energy is a stochastic fluctuating energy source. An installed power of one kilowatt in a wind converter delivers onshore 1600 to 2300 kilowatt-hours and offshore until 4000 kilowatt-hours. To meet the demand of the consumer wind energy must be embedded in a complex electricity system which is able to react quickly of alternative power stations on the wind fluctuations. Today these will be done by fossil fired power stations. In future the opportunity exists to set up a European wide network of wind energy parks and solar power stations with daily storages in south Europe in combination with new very flexible conventional power stations.
Enlarging wind energy use is only possible by extending the electrical grid in every European country which is introducing renewable energies on short term range. In Germany e. g. 800 km new high voltage lines are necessary to meet the political goal of 20% electricity from wind in 2020. Beside this there is the recommendation to build a European bulk electrical transport system on long term range to fulfill the idea of a European wide liberalised electricity market and the “renewable vision”.
Wind energy systems are material intensive. Additionally a lot of today’s conventional energy is necessary for their market introduction. To use wind energy in a reliable way, research work in terms of sustainability must be done. The results of Life Cycle Assessments show that wind energy converters have a short energy payback time and low emissions, even in comparison with other renewable energy systems.
Wind energy will be an important component of the future electricity system. This will be more sustainable than today’s, but also more expensive