The EU member states have passed a resolution requiring one-fifth of their
electricity needs to be derived from renewable energy sources by 2020, with wind
farms covering a large part of this requirement. Researchers have succeeded in
interconnecting large wind farms in clusters.
The future belongs to renewable energies. Wind energy is one of the main
forms of renewable energy experiencing a boom. According to the German Wind
Energy Association, 952 new facilities were installed in Germany in 2009. The
German Renewable Energy Federation predicts that 47 percent of total electricity
consumption in 2020, estimated at 595 terawatt-hours, will be covered by
renewable energy sources, with wind energy accounting for one quarter.
“Wind on the Grid”, one of the EU's biggest network integration projects, has
just been completed. A group of European industrial companies and research
organizations teamed up to investigate how wind farms on the Iberian peninsula
could be safely integrated in the European electricity grid on a large scale. To
assist grid operators in the capture, control and forecasting of wind energy,
the Fraunhofer Institute for Wind Energy and Energy System Technology IWES has
made available both its Wind Farm Cluster Management System (WCMS) and its Wind
Power Management System, adding new functions to both. The researchers used
these software packages to integrate five wind farms in Portugal with a total
capacity of 204 megawatts and six in Spain with a total capacity of 107
megawatts in the power grid. The integration was achieved in real-time tests
under a variety of weather conditions.
“We used the WCMS to link the scattered wind farms in a cluster, enabling
them to be controlled by the central control station of the Portuguese and
Spanish power utilities respectively. While the WCMS keeps both the frequency
and the voltage of the electricity grid constant, thus ensuring safe operation,
Fraunhofer's Wind Power Management System forecasting software uses artificial
neural networks to calculate expected wind energy on the basis of predicted
weather patterns,” explains Dr. Kurt Rohrig, department head at the Kassel
branch of the IWES.
Individual wind farms are subject to wide fluctuations in output. The more
wind farms that can be interconnected in a cluster, the easier it is to balance
out the fluctuations caused by variations in wind force, from gusty winds to
totally calm conditions. And the higher the number of installed facilities, the
lower the energy price.
“The price of electricity produced using wind energy is currently seven cents
per kilowatt-hour; by 2025 it should be around four cents,” says Rohrig.
Fraunhofer researchers are negotiating with the Portuguese grid operator with
the aim of integrating their software in the latter's control system. And Kurt
Rohrig is convinced: “In the long term, wind farms will replace traditional
power plants.”
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