Environmental Engineering Reference
In-Depth Information
variable speed gearboxes, computerized yaw controls, etc.) can signiicantly
attenuate wind power luctuations.
21
In fact at low levels of contribution to
an electricity grid, the stochastic nature of wind power poses limited threat
to grid resilience, because spare capacity already embedded in the average
electricity grid can smooth the lows.
22
Currently, research indicates that depending on the electricity grid base-
load proile, 10 to 40% wind energy can be integrated into an electricity grid
without having to add storage or additional spare capacity. For grids that
are dominated by coal-ired power stations, a 10 to 20% contribution from
wind power represents the current benchmark beyond which additional
storage or capacity additions become necessary.
23
For grids that are domi-
nated by hydropower or interconnected to other national grids, a 30 to 40%
contribution from wind power may be achievable without adding back-up
systems or electricity storage. here are already examples of nations which
rely on wind energy for up to 40% of total electricity demand.
24
Denmark
has set a goal of producing 50% of its electrical power through wind energy
by 2020 thanks to interconnections that Denmark has with the EU grid.
25
Indeed, some studies go as far as to conclude that even in systems with
inlexible base-load energy sources (such as nuclear power), the potential
contribution from wind energy (without adding reserve capacity) may cost
efectively reach as high as 50% in coming decades through better disper-
sion of wind resources, improved generation technologies,
26
and new energy
storage technologies.
27
In short, it is clear that criticisms of the stochastic nature of wind power
are largely invalid at current installed capacity levels for most nations.
A high level of development can still be undertaken in most nations before
the management of stochastic lows begins to have a signiicant economic
ramiication.
28
To accommodate higher levels of installed wind power capacity, there
are two technological approaches to improving technological resilience—
but both increase the cost of electricity generated. he irst approach is to
increase generation capacity of peak-load support systems such as hydro-
power or natural gas-ired power plants. Ensuring higher capacity in highly
responsive (peak-load) electricity generation technologies allows load engi-
neers to compensate for luctuations in wind power by adjusting output of
the reserve generators. In nations where peak-load technologies such as
gas-ired power plants are replacing coal-ired power plants, the resilience
of the grid is naturally reinforced, meaning that higher levels of wind power
can be added with few additional costs. However, in nations where peak-
load capacity must be added speciically to accommodate wind power, this
solution becomes costly because the investment is not fully exploited due
