Quantifying CO2 savings from wind power
The graphic is from a writeup of a calculation which indicates that CO2 emissions reductions associated with wind power were 0.279 tCO2/MWh for the Irish electricity grid in 2011. Wind power met 17% of electricity demand that year. Such savings are a lot lower than have usually been assumed. Most grid operators do not publish official numbers on the effectiveness of wind power each year, despite the large investment going into this technology. Fortunately in the Irish case, the detailed data required to do the analysis is publicly available.
co2calc contains the details of the emissions model and the simple statistical analysis. It uses 1/2-hourly generation data compiled from market operator www.sem-o.com. Zipped data files can be downloaded below, although the script can also be run directly in an R terminal without downloading these files.
windfarmGeneration_2011.csv.zip
thermalStationParameters.csv.zip
meteredGeneration_2011.csv.zip
The European Wind Energy Association claims that wind power saves 0.696tCO2/MWh, while the British Wind Energy Association uses a figure of 0.43tCO2/MWh.
A 2012 report by the Institute for Public Policy Research, a UK think tank, entitled “Beyond the Bluster: Why Wind Power is an Effective Technology” claims that “every megawatt-hour (MWh) of electricity produced by wind power in Great Britain results in a minimum CO2 saving of around 350kg”.
(Paper submitted to Energy Policy, Elsevier November 2012)
January 18, 2013
· 
joe · 
3 Comments
Posted in: Wind Energy
3 Responses
*Very* interesting. Which data exactly did you use on the http://www.sem-o.com site ? Is the data not yet up-to-date enough to get the complete 2012 values ? (I see the public weekly reports stop at 13/07/2012 for now, and the part that’s accessible after registration is not very easy to navigate)
Your “metered generation file” separates by generation unit, and the generation one contains the total, right ?
The semo site is indeed difficult to navigate. Also the data has to be downloaded one small piece at a time.
After registration and login, go to “Market Data”. Select Report Type “Dynamic Reporting”, Report Group “Energy Data” and Report “Metered Generation by Unit”. You can find unit codes in various places. e.g.
http://www.eirgrid.com/media/2011-2012%20ROI%20Market%20Participant%20TLAFs%20v3.0%20(13.07.12).pdf for example.
Well worth repeating for 2012.
Ireland 2013- Due to grid stability requirements wind is currently constrained to a maximum of 50% of instantaneous generation. When wind reaches 50% at times of high wind and low demand it can be noted that the CO2 intensity of the fossil generated electricity increases significantly, for example check the EirGrid website data for January 25th 2013; when wind hit 50% the CO2 intensity of fossil generated electricity increased by 66% over the level reported at the lowest wind period earlier that day. A 66% increase implies that 40% of the fuel burned at peak wind is wasted in order to facilitate 50% wind generation on the grid. This increased CO2 from fossil scenario happens frequently, just browse through the EirGrid data, many similar occurrences can be found.
Ireland’s 2020 target of 37% of annual electricity generation from wind (out of a total of 40% renewable contribution) will require a grid capable of accommodating wind peaks of 75%. To achieve this objective billions of Euros must be spent on constructing new flexible gas fired CCGT power generating plants, pumped storage and other grid stabilization equipment such as rotary condensers (decommissioned generators can be converted for this purpose). Failure to install the required grid improvements will result in fuel wastage on a scale far greater than that seen to date as existing power plants which are no longer fit for purpose are inefficiently operated on low load so as to maintain grid stability as 75% of the load is generated by asynchronous grid destabilizing wind turbines. The Irish electricity consumer should be properly informed as to the costs associated with the dash for renewable energy, to date the costs are under reported while the benefits are exaggerated.
In 2008 when the oil price was soaring the wind power industry stated that “the cost of wind power would break even with fossil power generation at an oil price of between $200 and $250 per barrel”. Today WTI is $90 and Brent is $105 implying a massive and increasing subsidy is paid to Irish wind power industry. The extent of this subsidy can be seen on your ESB bill where the PSO levy which covers a portion of the additional costs associated with renewable electricity generation is an approximately 45% levy on the cost of the renewable and turf portion of your bill. As renewable electricity increases from the current 15-18% to the planned 40% by 2020 expect this levy to increase considerably, unless fossil fuel doubles in cost. Ireland has decided in favor of wind power, the costs should be made public.
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