Onshore wind farms offset their carbon emissions within two years, new study finds

By Tanya Weaver. Fri 17 May 2024

Collected at : https://eandt.theiet.org/2024/05/17/onshore-wind-farms-offset-their-carbon-emissions-within-two-years-new-study-finds

A new study, which finds that onshore wind farms are capable of offsetting the carbon emissions generated across their entire lifespan within two years, “underscores the environmental efficiency of onshore wind farms and their important role in the energy transition”.

According to a new study from the Sustainable Energy Systems research group at the Wellington Faculty of Engineering, Te Herenga Waka Victoria University of Wellington, New Zealand, an onshore wind farm is capable of offsetting the carbon emissions generated across its entire 30-year lifespan within two years when compared to thermal power plants.

Additionally, the study found that within six months a turbine can generate all the energy consumed across its life cycle.

For its research, the team studied the Harapaki onshore wind farm in Hawke’s Bay, New Zealand, which comprises 41 turbines. They reviewed current literature on wind farms, as well as using real construction data of the Harapaki wind farm, which took into account everything from the manufacturing of individual turbine parts to transporting them into place and decommissioning.

The results indicate that this particular farm will leave a carbon footprint of 10.8 gCO₂eq/kWh, which equates to a greenhouse gas payback time of 1.5-1.7 years for avoided combined cycle gas turbines, and an energy payback time of 0.4-0.5 years.

While the research team analysed data from just this one onshore wind farm, they say their findings can be replicated across most, if not all, wind farms internationally.

“Although the carbon offset depends on the exact older technology the wind turbines are replacing, we would expect a similar offset internationally. In New Zealand it is gas turbines, but many countries will be displacing fossil fuel generators,” explained lead author of the study Isabella Pimentel Pincelli.

If onshore wind farms are capable of offsetting their carbon emissions in less than two years, to further reduce their carbon footprint the focus then needs to be on reducing the carbon emissions during their manufacture, installation and transportation phases.  

“It remains crucial to continue implementing improvements aimed at limiting negative environmental impacts while maximising positive contributions throughout the supply chain of onshore wind plants,” stated Professor Alan Brent, co-author and chair in Sustainable Energy Systems.

“Notably, the manufacturing of wind turbines is the primary contributor to the carbon and energy footprints, highlighting a critical area for targeted environmental mitigation strategies.”

The research team found that better recycling methods of end-of-life blades could further increase the environmental credentials of onshore wind farms. Most wind turbine blades are disposed of in landfill due to commercial feasibility, but the study found that recycling the blades could drop the emissions from the current 10.8 gCO₂eq to a potential 9.7.

In their study, the researchers focused only on the energy intensity and emissions throughout the life cycle of the wind farm, and did not take other environmental impacts into consideration such as ozone depletion, human toxicity, acidification, eutrophication and resource depletion.