By David Watson
THE forthcoming wind generation subsidy reductions have created much
dispute within Holyrood, and subsequent Agenda contributions from Scottish
Renewables have promoted further public and private wind generation
investment whilst almost totally ignoring the increasing engineering
challenges resulting from their policies. This from an organisation paid to
represent the wind energy generators, who are doing very nicely from the
existing subsidies.
Low carbon technologies have to be both affordable and, above all, meet the
energy reliability and flexibility needs of our industrialised society.
Several UK professional engineering institutions are now voicing huge
concerns about the growth of wind generation. Adding more offshore
generation increases those problems.
Regarding costs, the “Strike Prices” agreed with generating companies last
February under the UK Government bidding round (the Contracts for
Difference, or CfD) range for onshore wind from £79.23 /megawatt hour
(MWhr)t o £82.50/MWhr and for offshore wind from £114/MWhr to almost
£120/MWhr (all at escalatable 2012 prices) for generation from 2017 onwards.
The Prime Minister’s “onshore wind perhaps £70/MWhr” quote of two weeks ago
may indicate a UK Government intention to revisit the drawn out CfD bid
process.
The new Hinckley nuclear station strike price is £92.50/MWhr and requires
the new owners to cover all of their decommissioning/waste management
costs, denying them access to the existing £9bn assets of the Nuclear
Liabilities Fund Trust – the Scottish-registered company established 20
years ago to support waste management and decommissioning costs of our
existing stations.
However, fossil fuel back-up is required to facilitate the use of wind and
when it and system integration costs are included, resultant costs for wind
energy to reach customers are much greater than these strike prices,
although neither the UK nor the Scottish government has commissioned any
assessment of them for the paying public.
In a comprehensive 2011 study prepared for the Institution of Engineers and
Shipbuilders in Scotland by the former power network director of the
National Grid Company, the calculated probable costs for onshore wind
energy to reach customers ranged from £150 to £200/MWhr. This recognised
that wind output averages only 28 per cent of the capacity installed and
turbines have an operating life of around 25 years. The comparable figure
for offshore was from £210/MWhr to almost £300/MWhr allowing for a 30 per
cent higher average output.
The calculations for nuclear concluded that its cost to customers was
between one-third and half that of on shore wind.This recognised that
nuclear station output performance averages 91 per cent of installed
capacity with an operating life of around 60 years and included for the
cost of decommissioning, storage, disposal and lifetime re-fuelling.
On a cost to reach the customer basis therefore, which determines our
bills, nuclear was assessed to be by far the cheapest low carbon energy
option presently available. Gas had a similar cost, at half the pollution
of coal and has since fallen in price on world markets which situation may
continue for several years.
The technical problems we are creating by increasing wind generation in
Scotland are exemplified in the north east where Peterhead power station,
which is gas-powered and without carbon capture and storage (CCS), is now
mostly deployed in a crucial role to reinforce the local, weakened, network.
Scottish Renewables does not mention that SSE, the owner of both Peterhead
and many windfarms, contracts yearly with the National Grid Company to
supply up to 780 MW, around two-thirds of Peterhead’s capability, “as a
last resort to balance the system if there is insufficient capacity
available to the market”. This is primarily to offset anticipated,
recurrent, wind output collapse
Notably, from April this year, Peterhead will be further contracted to
provide crucial network “voltage support” to the grid.This implies that
much of the station will be continuously running while off network to
enable its automatic voltage regulators to inject “reactive power” quickly
enough to prevent grid voltage collapse.
Peterhead is predominantly “not otherwise available to the energy market
….with capacity only if called upon by the National Grid” , hence
dependable energy equivalent to one-third the capacity of a Longannet has
been removed from the north east network.
Any new major industry seeking to set up in, say, Aberdeenshire in future
will almost certainly have to consider costing in its own generating station.
While we are industrialising our landscape with wind turbines we are
concurrently de-industrialising the capability of our existing electricity
grid.
Throwing further national and private investment at wind generation has
more than mere overtones of another Scottish Darien Scheme.
David Watson is a retired chartered electrical engineer with 35 years’
experience in international energy engineering projects.
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