Report compiling wind integration impacts from IEA WIND Task 25
Some countries already get a substantial share of their electricity
consumption from wind power: Denmark 20%, Spain and Portugal 11%, Ireland 9%,
and Germany 7%. Power systems have to cope with variable electricity
consumption. Variable wind power will increase variations that the power
system has to manage. According to a recent IEA WIND report, wind energy is
rather smoothly integrated as system operators get on-line production levels
and forecasted production estimates in their control rooms.
High penetration of wind power is foreseen in many countries and regions
globally. Therefore the impacts of wind power on power system reliability are
widely studied. Wind integration impacts report by a research task for the
Wind agreement of International Energy Agency (IEA) has been compiled from
work done in Denmark, Finland, Germany, Ireland, Netherlands, Norway,
Portugal, Spain, Sweden, UK and USA. The report can be downloaded from IEA
WIND Task 25 web site or at /Documents/2009_T2493.pdf
Adding large amounts of wind power requires reinforcing the existing
transmission grid, including the interconnectors between countries and
regions. New transmission lines may be needed where the wind resource is
situated far from the existing network. Wind power will also increase the use
of operational balancing power and thus increase balancing cost in the power
The estimates for added balancing costs from
investigated studies are increasing wind power production costs by 1–4 €/MWh.
This is 10% or less of the wholesale value of the wind energy. Experience from
West Denmark shows that the balancing cost from the Nordic day-ahead market
has been 1.4–2.6 €/MWh for a 24% wind penetration (of gross demand). This is
in the middle of theoretically estimated results.
from larger areas helps integration
It is easier to
balance load and wind production from larger areas. This is because both wind
variability and uncertainty will be reduced when geographically diverse power
plants are aggregated. Additionally, larger balancing areas also can pool
balancing resources. Large open electricity markets combined with intra-day
and real-time trading lead to lower electricity costs. This market design also
facilitates wind integration, because forecast errors of wind power production
are much lower some hours ahead than day-ahead, and forecast errors also
decrease when combining distributed wind power plants.
wide, strong transmission network is a prerequisite for large electricity
markets and aggregation benefits to smooth out variability. Increase in
interconnection capacity between certain countries is needed in addition to
national efforts, allowing stronger trading of (also) wind generated energy.
Building the transmission for final amount of wind power will be more cost
effective than reinforcing the grid piece by piece. Ambitious wind power
targets in Ireland, Denmark, Germany, UK and US already foresee major upgrades
in the transmission network. This is challenging, as building permits for new
lines are difficult to obtain.
Studies show that despite its
variability, wind power can contribute for a certain percentage to meeting the
peak loads in a reliable way. This so called capacity value of wind power is
lower than for conventional power, and will decrease as the wind penetration
New electricity storage has still low cost
effectiveness for wind penetration levels of 10–20% (excluding some hydro
power and pumped storage). With higher wind penetration levels the extra
flexibility offered by storage will be beneficial for the power system
operation. However, other forms of flexibility from generation units or
flexible loads can offer cheaper solutions, if available to the power system.
In any case, it is not cost effective to provide dedicated back-up for wind
power in large power systems, just as it is not done for individual