Wind farms don’t need extra backup

This letter was published in the Bega District News last Friday 20th April.

It answers one argument that anti-windfarm campaigners commonly raise: even though many of them don’t believe in climate change anyway, some suggest that wind farms actually have high greenhouse gas emissions because of the need for constant “spinning reserve” in fossil fuel power stations, just in case the wind suddenly disappears.

Technical veracity

As one who works providing training services in the energy sector, I read John McKerral’s letter to the editor (17/2) with some concern regarding its technical accuracy.

I neither advocate nor oppose the proposal for Twofold Bay; my issue with Mr McKerral is the technical veracity of his argument.

My delay in responding was due to my need to refer his letter to other technical experts in the energy sector so as to be sure of my facts.

The electricity network always has some “spinning reserve” built into it.

A typical coal-fired power station has about 10 per cent spinning reserve to take up any unexpected load on the network (such as the failure of a generator in the network, as happened recently when the Eraring Power Station on the Central Coast failed a few months ago).

Wind turbine generators complement the base load generation of the conventional power generation stations.

Yes, winds do ebb and flow, as Mr McKerral points out.

And the remote control stations that operate the wind turbine generators use complex algorithms to harmonise the generation across their various sites such that the total variability of power generation is minimised.

If significant power variation was experienced, then the spinning reserve of the existing network could accommodate it.

There is no need to fire up gas turbine generators “just in case”.

Gas turbine generators are used for peak load demand such as very hot days when everyone turns on their air conditioner.

So does the spinning reserve of the coal-fired power stations negate the CO2 savings of wind generated power?


I say this with confidence by referring to the report: “GHG [Green House Gas] and Cost Implications of Spinning Reserve for High Penetration Renewables, Technical Assessment Report 73 – March 2008” from the CRC for Coal in Sustainable Development.

Quoting from the executive summary: “The often held view that operating larger fossil plants at part load to provide spinning reserve would negate the greenhouse gas emission benefits of wind is false”.

Given that this technical report comes out of the coal industry itself, I doubt it is biased towards wind generators.

The visual amenity of large-scale wind turbine generators is part of a separate and valid debate.

However, let us not simply discount a valid form of clean energy generation on falsehoods about the actual impact upon greenhouse gas reductions.

David Neyle

6 thoughts on “Wind farms don’t need extra backup

  1. I’ve worked in the power industry a long time, hydro, thermal, tranmission and now wind, and the “constant backup” argument against wind has been very frustrating.
    All generation requires backup, and the backup in the system to cover a coal generator is far more than required for wind. The system is run so it can loss the two biggest units (n-2) contingency. So enough reserve capacity to cover 1000MW+ of coal is more than ample to cover wind, or any other generation.
    Hopefully this misinformation about backup required for wind will decline.

  2. Pleased (and somewhat surprised) to see my letter picked up here. But thank you for spreading the message. I’m currently working on behalf of the national Industry Skills Council that manages the technical qualifications for those working in the energy sector ( Currently we are developing a CII qualification for young people to transition into the industry. This is targeted for VET In Schools training. This industry is creating real jobs for young people in regional Australia. It is a good news story and people need to hear it.

  3. Wind farms don’t need extra backup/Technical veracity
    You are quite wrong believing that coal-fired generators can be used effectively to support wind farms. They are much to slow reacting to be of any use, anything involving steam is. OCGT (open cycle gas turbine) powered or hydro generators are needed as they are very fast reacting and are thus used.
    Wind requires close to 100% back up. Spinning OCGT must quickly increase or decrease output to accommodate wind, running in a very inefficient mode. That is expensive and puts out a great amount of CO2, what you are trying to reduce! Any supplier running OCGT in this fashion will want plenty of money to operate in this fashion.
    OCGT is usually used for peaking but will function adequately supporting wind.

    1. John, thanks for your comments, if wind were unpredictable you might be correct – but forecasts are 95% accurate, 24 hours out; so they don’t actually need to keep OCGT idling permanently. That myth was spread for some time, quite disingenuously, by opponents of wind farms; it’s simply not true and extensive experience (such as in South Australia) has proven that.

      1. Thanks Ben for chiming in and dispelling these myths. When you have been inside the industry and understand how loads are balanced across the network them you truly understand why there is no need to have gas turbines spinning away “just in case”
        . Except in extreme situations (eg a tornado ripping down your interconnector) the spinning reserve in the network can adequately cope with fluctuations from wind generators.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s