HAVING digested Jenny Hogan’s defence of wind power (“Time truth was told
about the vital role of renewables in our wellbeing,” Agenda, The Herald,
April 22), I feel I must respond.
As the policy director of Scottish Renewables she is clearly concerned that
wind energy is getting an increasingly bad press because of rising
constraint payments with wind farms being shut down by the National Grid
controller, and being paid for not producing electricity. By her own
estimate £39m was paid to UK wind farms for this reason over the last
12-month period.
Her defence seems to be that fossil fuel generators are also paid for not
putting power on the grid – about £270m over the same period. What she does
not point out, or perhaps does not understand, is that the majority of
these payments are also due to the deployment of wind power, forcing the
fossil fuel power stations to operate less efficiently.
Wind may well be responsible for nearer to £200m of constraint payments for
our bills, rather than the £39m declared.
It used to be the case that a small “spinning reserve” was all that was
needed at some gas-fired power stations to cover for the occasional
unexpected blips in supply or demand on the grid caused by unit failure,
weather damage or unexpectedly high or low customer demand. However these
were rare events, probably amounting on average to no more than one
incident per month.
The advent of wind power with significant amounts of variable and
unpredictable power spikes and slumps being offered to the grid coming from
many wind turbines powering up or down more or less together, forces more
conventional power stations, especially gas-fired power stations, to run or
be constrained much more frequently.
For example, over the 30 days of a recent November, six very large power
spikes and eight almost complete power slumps were experienced from the
combined output of all wind farms in the UK. Constraint payments would have
been made on all of these occasions, both to the wind farm operators and to
those companies providing the balancing reserve power.
Renewables are of course a very mixed bag – hydro, biomass, and solar are
very much more controllable and predictable technologies, and at the level
they are deployed, cause no real problems for the grid.
Wind power is vastly different, expensive and inefficient in ways that we
have yet to get our minds fully around.
Bruce McIntosh,
Corriedoo,
Dalry,
Castle Douglas.
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