The repowering of 23 projects in the UK boosted their capacity by 171% on average, the research stated.
By enlarging the 215 operarting projects facing an end-of-life decision within the next ten years by the same rate could boost their combined capacity from 3,225MW to 8,740MW.
Meanwhile, 55 wind farms facing an end-of-life decision within the next five years could have their capacity raised from 666MW to 1,806MW, the researchers said.
Most existing UK wind farms were originally granted temporary 25-year planning consents. At the end of this term, turbines would normally have to be removed and the site returned to its previous use.
A provision in the UK’s National Planning Policy Framework, released in July, enabled local authorities to allow proposals to upgrade or repower existing wind farms.
Time to act
While the study highlighted the potential benefits repowering offers in terms of boosting output, in an article for academical news outlet The Conversation, Cardiff University PhD researcher, and the report author, Rebecca Windemer, conceded changing the appearance of wind farms could pose challenges when it comes to gaining local planning approval.
The number of turbines at the 23 already-repowered projects was reduced by 24% during the repowering process, while their height has been increased by 89.5% on average, researchers at Cardiff University revealed.
Windemer concluded: "Despite the evident benefits to repowering wind farms, there is still not enough governmental guidance to ensure that decisions can be made quickly and fairly in a way that balances energy production with local environmental, social and economic benefits.
"This is not an issue that the country can sit on. With so many wind farms approaching their 25th year, we need to act quickly in order to maximise the potential benefits to energy generation and carbon reduction targets."
Route to market
While offshore projects have thrived in the UK’s contract for differences (CfD) auction regime, most onshore wind farms are barred from competing in tenders.
Further, in June 2015 the government introduced additional planning conditions for onshore wind projects in England that lobbyists 10:10 Climate Action described as "all but impossible to meet".
In the year and a half after these conditions were imposed, the number of applications for onshore wind projects in England fell by 93.6% compared to the previous 18-month period, according to 10:10 Climate Action.
In October, these difficulties prompted a group of renewable energy developers, turbine makers, tower manufacturers, civil engineers, asset managers and consultants to write to the government demanding onshore wind be allowed to compete at auction.