Powering Europe - European Wind Energy Association

alancingdemand,conventionalgenerationandwindpower
fiGURE 3: balanCinG anD oPERatinG Costs DUE to winD PowER as fUnCtion of winD EnERGy PEnEtRation
The main contributing factors to lower balancing
costs are:
• larger areas: Large balancing areas offer the benefits
of lower variability. They also help decrease the
amount of forecast errors in wind power forecasts,
and thus reduce the amount of unforeseen imbalance.
Large areas favour the pooling of more costeffective
balancing resources. In this respect, the
regional aggregation of power markets in Europe is
expected to improve the economics of wind energy
integration. Additional and better interconnection is
the key to enlarging balancing areas. Certainly, improved
interconnection will bring benefits for wind
power integration, as explained in Chapter 2.
• Reducing gate-closure times: This means operating
the power system close to the delivery hour. For example,
a re-dispatch, based on a 4–6 hour forecast
update, would lower the costs of integrating wind
72
Euros/MWh wind
4.5
4
3.5
3
2.5
2
1.5
1
0.5
Increase in balancing cost
0
0% 5% 10% -15% 20% 25% 30%
Wind penetration [% of gross demand]
Nordic 2004
Finland 2004
UK 2002
UK 2007
Ireland
Colorado US
Minnesota 2004
Minnesota 2006
California US
Pasicorp US
Greennet Germany
Greennet Finland
Greennet Norwy
Greennet Sweden
Greennet Denmark
for the Uk’s 2007 study, the average cost is presented here, the range in the last point for 20% penetration level is
from €2.6 to 4.7/Mwh (iEa task 25 final report) 3 .
3 The currency conversion: €1 = £0.7 and €1 = US$1.3
power, compared to scheduling based on only dayahead
forecasts. In this respect the emergence of
intra-day markets will facilitate larger amounts of
wind energy in the system – see Chapter 4.
• improving the efficiency of the forecast systems:
Balancing costs would be decreased if wind power
forecast accuracy was improved, leaving only small
deviations in the rest of the power system. Experience
from different countries (Germany, Spain and
Ireland), shows that the accuracy of the forecast
has been improved in several ways, ranging from
improvements in meteorological data supply to the
use of ensemble predictions and combined forecasting.
In the latter two, the quality of the forecast
is improved by making a balanced combination of
different data sources and methods in the prediction
process (see also Chapter 2, section 1).
Powering Europe: wind energy and the electricity grid