Powering Europe - European Wind Energy Association

At European system level the EWIS study (penetration
of 10%, time horizon up to 2015) found additional
balancing costs in the order of €2/MWh,
which is well in the range of the other studies. A
very important common finding of system studies is
that there is no steep change in required reserves
or the cost of their deployment with increasing penetration.
The estimations of the studies may be on
the conservative side because in practice system
operators use forecasts in a much better way than
assumed in the models.
• Aggregating wind power over large interconnected areas
and dispersed sites and using combined predictions
helps to bring down the wind power forecast
error to manageable levels in the time frames relevant
for system operation (four-24 hours ahead).
To help efficiently integrate wind power, forecasting
tools should be installed in the control room of the
system operator. The cost-benefit ratio of applying
centralised forecast systems is very high – because
of the high reduction in operational costs of power
generation corresponding to reduction in uncertainty.
Forecasting needs to be customised to optimise
chApTEr 3 powersystemoperationswithlargeamountsofwindpower
the use of the system reserves in the different time
scales of system operation. It is important to develop
ways of incorporating wind power uncertainties
into existing planning tools and models, and in this
area more R&D is needed.
• Clustering wind farms into virtual power plants enhances
the controllability of the aggregated wind
power for optimal power system operation. Practical
examples, for instance in Spain, demonstrate the
benefits of the coordinated operation of distributed
variable generation sources as a means to manage
their variability and enhance their predictability, supported
by dedicated national and regional control
centres put in place by the system operator.
• Wind power capacity replaces conventional generation
capacity. The capacity credit of large-scale wind
power at European level is in the order of 10% of
rated capacity at the wind power penetration levels
foreseen in the TradeWind medium scenario of
200 GW in 2020. Aggregating wind power from dispersed
sites using and improving the interconnected
network helps to increase its capacity credit.
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