A rebuttal of the wind industries claims made at Engineers Ireland presentation May 2014
By Owen Martin
At the Q&A session following Dr.Anthony White’s presentation at Engineers Ireland last Wednesday, a number of points were made by the wind lobby in an attempt to disprove Dr.White’s assertion that there was a 20% limit on the amount of wind energy that could be accommodated by the grid.
An SSE Airtricity Representative claimed that wind energy could power 100% of Ireland’s electricity needs. This is a ridiculous statement as Airtricity are investing in gas plants themselves e.g. Great Island CCGT, so the idea that Airtricity are interested in closing conventional plant, as this statement implies, is false. It is also a technical impossibility. Dalkia VPP, a demand side unit operator, state that “as the amount of renewable generation increases, the TSOs will need to keep higher levels of operating reserve available”. With increased levels of wind penetration in the system, Eirgrid cannot shut down back-up plant without replacing it with new back-up because, as stated in their 2007 Adequacy Report, “there is a significant risk that a single source of failure (i.e. very low or very high wind speeds across the country) will result in all wind farms producing practically no output for a number of hours even allowing for geographic diversity”. New fossil fuel plants are being commissioned at present. Tarbert heavy oil plant was due to close last year but will now remain open as Eirgrid realise that large amounts of spinning reserve is essential to keep the lights on.
An Eirgrid Representative claimed that Eirgrid welcome more wind energy as it makes their job easier. This contradicts most of Eirgrid’s own Adequacy Reports e.g. in their 2007 report they state “Analysis based on 2005 wind data established that the [wind] capacity credit is reasonably significant at low levels of wind penetration but the benefit tends towards saturation as wind penetration levels increase”. So there comes a point when wind doesn’t displace any conventional generation at all and therefore becomes of no use. In Eirgrid’s 2014 Capacity Statement, they state that the cycling of plants at morning and night “occur more frequently with increased penetration of wind generation” and that this results in increased maintenance and monitoring of back-up plant. Forced outages, when plant breakdown without notice, have risen since 2010.
What has actually made Eirgrid’s job easier is the increase in dispatchable plant.
An SEAI Representative claimed that there have been no problems with spinning reserve.
Not without financial incentives and more investment. In a free market, back-up plant would switch off altogether at times of high wind penetration in the system but this would mean that power could not be dispatched quickly when the wind fell. This particular problem was overcome through financial incentives called capacity payments (paid by consumers) to maintain plant at a critical level. There are also well known inefficiency problems associated with increased cycling of plant.
IWEA claimed that wind energy reduces dependence on fossil fuel and the wholesale cost of electricity. The opposite is the case. Conventional generation capacity, mostly fossil fuel, has increased by 21% since 2006 so Ireland is now more dependent on fossil fuel, mostly gas and oil, than ever before. Any reductions in wholesale costs are more than offset by levies and hidden costs (constrainment / capacity payments, grid investments, additional back-up etc) paid by consumers in their final electricity bills, now the third highest in Europe. As Professor Gordon Hughes points out “Heavy reliance upon wind power significantly increases the costs of supplying electricity due to higher cost of balancing and transmission”.