Integration of wind energy by load management
As the amount of wind generation within an electricity supply system increases, the impacts on power system operation become evident leading to extra costs on the one hand as well as effecting reductions of CO2-emissions on the other. The existing literature does not provide clear information, to which extent these effects are influenced by the configuration of the power system and whether measures on the demand side allow more efficient integration of this renewable energy source.
Wind power production replaces production from fossil fuel fired power plants and therefore reduces CO2-emissions in the range of 0.75 tCO2/MWh(wind) for 2005 in Austria. This specific reduction declines by about 20-30 % until the year 2020. In Germany the corresponding numbers are higher due to the higher share of coal units in the system. Additional wind related emissions reduce the CO2-reduction effect by 8 % for highest wind penetration levels in Germany. Extra costs occur due to impacts on the operation of conventional power plants and because of additional requirements for minute reserve and balancing power. The latter effect is dominant for the current wind penetration and becomes increasingly relevant with a rising share of wind power in the system. According to the baseline-scenario specific total system operation costs rise up to 1.8 €/MWh(wind) for Austria und 3.5 €/MWh(wind) for Germany in 2020. Better wind power forecasts can lower these costs by up to 30 % in a medium term perspective. If the flexibility of the power system decreases due to congestions, balancing costs may rise by 15 % in the worst case.
Activating demand response is an adequate measure to react on the limited contribution from wind power to system security especially when conventional capacities decline. Potentials on the demand side are available to a considerable extent in different consumption sectors and can be activated anytime which is not the case for building new power capacity. For balancing groups with an increasing share of wind power production flexible loads can be used as an option to limit costs for balancing power.
For the short to medium term better wind prediction is the key aspect for integrating wind power more efficiently. Flexible loads can rise the value of wind power especially when system capacity reaches critical limits. Current approaches for allocating wind related grid extension und connection costs in Austria and Germany do not consider the fundamental unbundling principle. Therefore in Austria a discrimination-free access to the grid cannot be guaranteed. An efficient use of the offshore potential in Germany is only possible if the extension of the coastal grid is coordinated and financed by the grid operator.
Project leader (Contact address)
Dr. Hans Auer
TU-Wien, Institut für Elektrische Anlagen und Energiewirtschaft (EEG) Gusshausstrasse 25-29/E373-2, A-1040 Wien
Tel. +43 (0) 1/58801-37357
Fax +43 (0) 1/58801-37397
Fraunhofer Institut für Systemtechnik und Innovationsforschung (FhG-ISI) Karlsruhe (Werkvertragspartner)