For many of us the wind/pylon debate has been an eye opener on many levels. For me, in my naivety, the level of lobbying power of big business and the absence of real evidence informed debate is staggering. I knew of course that spin (excuse the pun!) exists in decision making but surely once the facts are presented to decision makers they’d change their mind?!…as I said, naive!
We have all had to educate ourselves, in the absence of leadership, on issues we previously knew nothing about and have trawled through technical reports and economic analysis which are by no means light bedtime reading! In this series of blogs I hope to give my understanding of some of the key reports which inform the stance of Wind Aware Ireland and many other wind and pylon campaigners and which I believe completely undermine the sustainability of wind energy and associated grid upgrades from and economic and environmental point of view.
The first two reports we’ll have a look at are Joe Wheatley’s paper ‘Quantifying CO2 savings from wind power.’ published in the journal ‘Energy Policy’ in 2013 and the analysis ‘Wind Energy in the Irish Power System’ by Fred Udo published online in 2011.
Most analyses of wind energy use assumptions and projections to come to conclusion. That is the nature of these types of studies. So, if the wind blows at a particular strength for a particular period and if conventional generation of electricity runs at a lower rate for this period then the CO2 or fuel import savings will be X. What is interesting about both these studies is that they are based on real time data, that is, what really happened.
We are lucky in Ireland that Eirgrid publish on their website a breakdown every quarter hour of what type of generator is supplying electricity and what CO2 is being emitted. This allows for detailed analysis.
For most of us, we would have assumed that if at any time the wind provides 20% of our electricity then we must be saving 20% of CO2 emissions and 20% of fuel import. Right? …Wrong! The reason being that we don’t turn off conventional generators when the wind blows, we turn them down, then back up again to match the intermittent wind.
Joe Wheatley is a physicist who now researches aspects of climate science and geostatistics. His paper looks at the potential CO2 cost from wind energy generation which he describes thus: ‘When the wind is blowing, priority is given to wind generation over conventional capacity. However an idling thermal plant is like a car crawling along in traffic – not doing very much but still burning fuel. This may cause thermal plant to burn more fuel per unit energy generated than would otherwise be the case.’
And it gets worse. To match wind we need to turn down and up quick acting generators, which tend to be the cleaner types such as gas rather than the really dirty plant such as peat. We pay these generators to remain on, producing electricity which never makes it to the grid. These payments are called capacity payments. Worse still, we are actually adding very quick acting diesel generators to the system in recent years in order to cope with additional wind energy on the now volatile grid.
The Wheatley paper found that when wind provided 17% of electricity there was an emissions saving of 9%. Most of the emissions displaced by wind are from four clean gas units. When these are running at part load, i.e. turned down, their emissions intensity rises.
Fred Udo is a Dutch physicist who worked on the CERN project. (You may remember the discovery at CERN recently of the ‘God particle’?). Fred also analysed data from the Eirgrid website in 2011 and found that in April 2011, 12% of electricity was produced by wind and this caused a reduction of CO2 emissions of 4%. When wind supplied 34% of electricity CO2 emissions decreased by 6%. He states that: ‘In general it is shown that the CO2 saving decreases with increasing wind contribution to the electricity supply. The consequence is that an investment of billions of Euros in wind turbines produces not more than a few per cent reduction in CO2 output. This analysis does not take into account the energy necessary to ramp the conventional generators up and down nor the energy to build wind turbines nor the extra transmission lines with their additional losses. It is highly probable, that taking all these effects into account will show, that the few per cent gain in CO2 will revert to a loss (i.e. an increase in CO2).’
Wind energy can only be considered as part of the system of electricity generation so the difference in the study findings can be understood when you consider the question: ‘Does wind energy have environmental/economic benefits?’ The answer depends on the precise balance between the conventional generation we are actually displacing, the inefficiencies this causes, and consideration of all the detailed costs and benefits of wind power.
Amazingly, in Ireland, this analysis has never been done.
Written by Paula Byrne