How can wind turbines be even greener?

Renewable, green electricity from wind turbines.

Onshore wind is one of the cheapest forms of electricity generation and of course, is 100% renewable. In the UK, the cost of electricity from onshore turbines is lower than the wholesale electricity price and forecast to get even cheaper. According to RenewableUK - an organisation representing companies and academics involved in the renewables sector - a doubling of the UK’s onshore wind capacity to 30 gigawatts by 2030 would reduce consumer bills by £16.3 billion over the decade and save around 6 million tonnes of carbon emissions a year. Clearly it could play a key part in achieving the government’s pledge to achieve zero carbon electricity generation by 2035.

So where's the catch?

The act of building any infrastructure for new wind farms – as with all construction – obviously has an inherent carbon cost, and with the essential drive to Net Zero, it is the duty of all design engineers and construction teams to minimise this. This means that considering carbon emissions from construction must become integral to the design and construction process.

In this episode of "Ask Andrew", Andrew Lees visits Hyndburn Wind Farm in Blackburn, UK to tell us how wind turbines can be even greener. 
 

Identifying the current carbon cost of wind farms

Let’s look at roads and crane platforms. A typical wind farm in the UK could require anything from 5-20km of new roads to access the site and reach turbine locations for construction and maintenance, with some requiring much more than this; additionally, there is a need for a large crane operating platform for each turbine. In the UK, wind farms are usually constructed on upland sites, with peat soils or lowland sites that have soft clay or silty soils. Traditionally this would require thick layers of imported aggregates to build stable roads and platforms: on peat soils, for example, the thickness of the aggregate layer would likely exceed one metre. The carbon cost of quarrying and transporting this volume of aggregate is huge in itself, as well as its impact on local roads and communities with large numbers of heavy trucks travelling to and from site, often on small rural roads

Reducing the current carbon cost of wind farms

The volume of imported aggregate and its carbon footprint can be reduced dramatically by the use of Tensar geogrids. One or more layers of geogrid within the aggregate fill creates a mechanically stabilised layer that is stronger and stiffer than aggregate alone. The result is that aggregate layer thickness can be reduced by 30% or more. Tensar has collaborated with the construction teams on many wind farm projects worldwide, saving thousands or tonnes of aggregate and associated carbon emissions.

Net Zero goals

In a poll by Survation published on 13 October 2021 by RenewableUK, 72% of the UK public want the Government to set a long-term target for wind ahead of the UN climate change summit in Glasgow, November 2021. If that wish is fulfilled its good to know that Tensar and others in the sector are ready to deliver the target on an even greener way than now, and at minimum carbon cost. 

Source:
Renewables UK

Want to "Ask Andrew"?

Got a burning question about geotechnical engineering? What is the bearing capacity of soil? What is the shear strength of soil? If you've got a question like this, then we know the man to ask!

Send Andrew your questions by popping it in the comments box below or submit them directly at: https://bit.ly/3CRyICP