The movement to hinder action to reduce greenhouse emissions seems to be bizarrely populated by conspiracy theorists that badly over-rate their own analytical abilities. And The Australian newspaper seems to have a great attachment to publishing their views without adequately assessing them against the large body of available evidence.
Usually it involves a well-intentioned old retired engineer or geologist who doesn’t lack for confidence in delving into fields over which they have limited experience and expertise, or have long since retired from. These people will often bail me up to wave several printed pages of spreadsheet calculations in front of me that they believe have proved CO2 has no part in warming the planet.
And in The Australian newspaper on 1 September the journalist Graham Lloyd, decided to raise to our attention the spreadsheets of Hamish Cumming. The newspaper article boldly claimed that any emissions gains flowing from the carbon tax are,
“swamped by a two-year analysis of Victoria's wind-farm developments by mechanical engineer Hamish Cumming. His analysis shows that despite receiving hundreds of millions of dollars from green energy schemes driven by the renewable energy target, Victoria's windfarm developments have saved virtually zero carbon dioxide emissions in the state.
A forensic examination of publicly available power-supply data shows Victoria's carbon-intensive brown-coal power stations do not reduce the amount of coal they burn when wind power is available to the grid.
Cumming says surplus energy is wasted to make room for intermittent supplies from wind.
Climate Spectator got in contact with Mr Cumming and found him to be a well-intentioned and intelligent farmer and mechanical engineer, deeply concerned for the welfare of Brolgas in Western Victoria.
But while he might have graduated at the top of his class from mechanical engineering at Victoria University in 1983, the electricity system and markets aren’t exactly his day job. And unfortunately it appears that his lack of familiarity with the electricity sector has led him to misinterpret a number of pieces of information he believes show wind farms aren’t reducing CO2 emissions.
Failure to take into account cross-state flows of electricity
It appears that Mr Cumming thought that the extra power coming from wind farms was being wasted, because he found AEMO data that showed 5 minute periods of time where the electricity generation of all the Victorian generators, including the wind farms, was surplus to Victorian electricity demand (as measured separately by AEMO on a 30 minute basis).
However it isn’t much of a secret that La Trobe Valley generators haven’t materially altered the amount of coal they’re burning over the years. But it’s not because they are venting large amounts of steam or their electricity generation is being spilled in order to accommodate the variable power coming from wind farms. They are in fact contributing the same amount of power and it is continuing to usefully contribute to demand.
So does that mean that wind power does not displace fossil fuel consumption and therefore is not saving any CO2 emissions?
Quite simply no, and that’s because it’s fossil fuel generators outside of the LaTrobe Valley that are for the most part getting squeezed out by wind power. What Cumming failed to account for was the fact that this surplus generation was not being wasted, but was largely accounted for by exports to other states, particularly NSW.
In the National Electricity Market the NSW and South Australian Coal Generators for a large proportion of the year (particularly outside peak demand periods) are the swing generators that are the first to get squeezed out. The La Trobe Valley generators have such low operating costs that if they get displaced by wind in the bidding order in Victoria or South Australia, they then just export the electricity to NSW instead.
Contrary to Lloyd’s suggestion that a,
“two-year email exchange between Cumming and energy companies and government regulators shows how the industry would prefer to rely on models than real world data”,
there is copious real world data that supports this contention.
When you review real-world AEMO metered (not modelled) data across all the states, as is done in the latest Pitt & Sherry CEDEX emissions index published on Thursday in Climate Spectator, it reveals that wind power has grown (as has gas) at the expense of output from black coal generators in SA and NSW.
Inaccurate citation of supporting experts
Graham Lloyd claims in his article that,
“Cumming's findings have been confirmed by Victoria's coal-fired electricity producers and by independent energy analysts who say it is more efficient to keep a brown-coal power-station running than turn it down and then back up.”
From what is cited in the article, it appears those providing confirmation are International Power-GDF Suez and Hugh Saddler.
Yet Hugh Saddler explained in Climate Spectator on Thursday,
“For the past six years, gas-fuelled and wind generation have steadily grown, the hydro supply has fluctuated with rainfall, and total demand rose for the first two years, since then it has steadily fallen. All adjustments have been accommodated by changes in output from black coal power stations.”
And according to Saddler total emissions from electricity generation are now at their lowest level since 2003.
Also you’d struggle to see the e-mail exchange between Cummings and International Power as a detailed confirmation of Cummings’ assertions. Firstly and most fundamentally it doesn’t address the fuel consumption of black coal generators in NSW and SA. But it also represents an almost comical attempt by a company to politely fob-off a member of the general public, who was asking highly detailed questions about operation of their plant that they didn’t really want to answer.
Cumming first starts by asking for hour by hour break down on coal consumption and they tell him the total amount of coal mined in the LaTrobe Valley over the previous year. Cumming then asks, “is the coal consumption across the generators the same rate (approximately) any time during the day or night, or do the generators slow coal consumption during any time during the night?” An employee from Hughes Public Relations then replies on behalf of International Power that the generators’ output is relatively constant, but doesn’t specifically answer his question.
Climate Spectator contacted International Power about this correspondence and was informed that it was only intended as a highly generalised response about how their plants operate. In addition I have also sought the input of others directly involved in operation of LaTrobe Valley generators, as well as Hugh Outhred, a past professor of electrical engineering at University of NSW. All have confirmed that it is complete nonsense that coal generators don’t vary their coal consumption in alignment with changes in their output dispatch.
Getting megawatts confused with megawatt-hours
Lastly, in an illustration of profound ignorance, the article states,
“Cumming references an AEMO presentation ….where the AEMO showed that for the wind farms in SA in 2009 the greenhouse gas abatement was only 3 per cent of the total capacity of the wind farms installed.”
Now I contacted AEMO about this and they replied,
The 3% referred to by Hamish Cumming in Graham Lloyd’s article refers not to abatement but to wind contribution at peak demand.”
Wind power may not represent a one for one replacement for a megawatt of a conventional power plant for meeting peak demand, but a megawatt-hour of wind generated electricity will largely displace the fossil fuels and CO2 involved in producing a megawatt-hour from a coal or gas plant.
Cumming would like the Auditor General to do an investigation into whether wind farms are having a genuine impact on CO2 - this might actually be a good idea. It could help in putting a stop to the kind of poorly researched rubbish currently being printed about wind farms.