Australian Wind Alliance

Carbon emissions way down in South Australia

Nick_Xenophon.jpgA myth bandied about sometimes is that wind farms don't reduce carbon emissions. It turns out not to be true; carbon emissions in wind-friendly South Australia, for example are right down, the Australian Wind Alliance has told the Senate Inquiry into Wind Turbines.

The question was asked to be answered on notice by committee member Nick Xenophon. We got this response to him.

Senator Xenophon’s question in full: “You raised the issue of life cycle figures for wind turbines. Does that take into account what appears to be thermal generators being on standby because if wind drops off they need to pick that up?”

Australian Wind Alliance response

The life cycle figures quoted in our submission reflect the amount of carbon dioxide equivalent (CO2e) emitted across its entire life from construction to decommissioning for each kilowatt hour of electricity dispatched by a wind turbine. The slightly old ISO-standard figures suggested around 12 grams CO2e/kWh while the more modern Vestas V112 turbine (installed at Macarthur Wind Farm in South Western Victoria) emits as little as 6 g CO2e/kWh.

In the Australian context, this compares to an average of 922g CO2e/kWh emitted through the operations of the National Electricity Market’s entire generating fleet. This figure reflects only emissions from operations. To compare like for like, total life cycle emissions for the NEM grid would be much higher once emissions for construction, materials, decommissioning, etc were taken into account.

If a kilowatt hour of wind energy displaced a kilowatt hour from our existing grid you would see emissions reduce from at least 922g to 6g CO2e/kWh for that kilowatt hour.

Senator Xenophon’s question goes to the amount of coal or gas power that is actually displaced by wind power, taking into account the need for thermal generators being on standby or ‘cycling’ beyond what they would normally do in a grid without wind energy.

The Inquiry has heard evidence that what is required to properly answer this question is to analyse actual emissions data at short time intervals from coal-fired power stations. Just such a study was conducted in 2013 by America’s National Renewable Energy Laboratory (NREL) using hourly emissions data from nearly every power plant in the Western U.S. It was reviewed by 55 experts including representatives from eight utilities.

This study found that the emissions cost of cycling was ‘negligible’ and that a ‘high wind scenario’ of 25% wind and 8% solar produced a 29% - 34% decrease in CO2 emissions. That is, 1 kWh of wind (or solar) generation displaces almost all the emissions from the coal- and gas- fired power stations that remain in the grid, even when cycling is taken into account.

Research regarding the real-world example of South Australia quoted in our submission (Osmond and Osborne) provides a similar result, finding that an increase in wind generation from 6% to 28% in that state between 2005/06 and 2012/13 reduced emissions by 34%. One a one-for-one basis, one kilowatt hour of wind energy displaced over 1kg of CO2e emissions.

 

2005/06

2012/13

Total Demand (GWh)

13700

13900

Total Wind generation (GWh)

765

3487

% of total generation

5.6%

25.1%

Additional Wind generation (GWh)

 

2722

Emissions (KT CO2e)

9340

6200

Change in emissions (KT CO2e)

 

-3140

Emissions change per additional unit of wind generation (KT CO2e/GWh)

 

-1.15

Together, these two pieces of research suggests that wind energy, even at high penetration levels, does indeed displace the full emissions of the coal and/or gas fired power it replaces.

The Australian Wind Alliance also made a more detailed written submission to the inquiry.

 


Showing 1 reaction

  • published this page in Blog 2015-06-09 15:13:09 +1000