Harnessing the Power of the Wind

In 2015, with the signing of the Paris Climate Agreement, nearly 200 countries pledged to limit global temperature rises to less than 2°C above pre-industrial levels.

In order to achieve this, and future goals, countries need to reduce reliance on fossil fuels and find more sustainable ways of producing the energy we need. The EU has set a target of obtaining 32% of energy from renewable sources by 2030 and other countries, including Australia, Canada and the USA, have similar goals.

The Carbon Trust has concluded that offshore wind power has the greatest potential to deliver renewable electricity power, and in 2019 the UK government revealed the cost of generating power this way has plummeted 30 per cent in two years. This makes it cheaper than new gas and nuclear power.

Offshore wind turbines harness the power of the wind to generate carbon-free renewable energy. They work in the same way as onshore generators but as offshore winds are generally stronger than on land, capacities are higher*. However, offshore wind farms are more expensive to install and maintain. As a consequence, research focuses on creating innovations that reduce installation costs and enhance reliability for shorter maintenance intervals.

At the University of Exeter, the Offshore Renewable Energy

group has more than 20 years’ experience in offshore renewable energy, including wave analysis; marine hydrodynamics; resource modelling; moorings; testing; reliability engineering; offshore installation, monitoring, operations and maintenance.

Lars Johanning is Professor of Ocean Technology on the Penryn campus and leads this group.

He said: “Constant technical innovations and scaling is making

wind energy cheaper and cheaper. Turbines have become larger and much more efficient so they are more cost effective. Innovations have reduced the installation and

maintenance costs for offshore fixed turbines even further, making wind energy today the cheapest source of electricity generation in the majority of places in the world. Cheaper than any other energy source, including conventional power generation sources such as nuclear, coal and gas. Plus floating

turbines now mean offshore wind farms can be installed in much deeper water, opening up more potential sites across the world.”

Exeter research in this area is being applied globally. A joint

UK-China Offshore Renewable Energy (ORE) programme aims to develop the next generation of technologies to enable the safe, secure, cheap and efficient provision of clean energy around the world.

Lars said: “There are five collaborative, interdisciplinary

projects that aim to tackle key technology and engineering

challenges affecting the development of ORE systems. We are looking to maximise the environmental and socio-economic benefits, as well as improve other key considerations such as deployment, planning and management.”

Lars is leading on one of the projects that focuses on system resilience. He said: “The vision is to improve energy security while reducing environmental impacts. We are looking to create robust structural designs that are able to operate in extreme conditions so can be relied upon to continuously produce power. This also gives us more flexibility in where wind farms are based so we can choose locations that have minimal impact on marine environments.”

Lars also advised in the development of the EU Ocean Energy Roadmap, a plan for how offshore renewable energy can be expanded successfully. This has suggested ocean energy could

meet 10% of the European Union’s power demand by 2050 and avoid the equivalent of 276m tonnes of CO2 emissions annually. In response more than €40 million has been made available to support research and innovation activities designed to advance renewable energy technologies and operations.

The UK currently has more installed offshore capacity than any other country. The world’s largest offshore windfarm sits off the coast of Yorkshire and began powering the grid in 2019, but this will be overtaken with a new development due to start generating power in 2023 that will provide electricity for 4.5m homes. This wind farm will use the latest technology in floating turbines.

While there is a significant global focus on offshore energy,

renewables research at Exeter also covers developments in solar energy, geothermal, storage and policy, putting it at the forefront of clean energy research.

Plus it’s not just through research where the university is committing to clean energy. In 2019, 20 of the UK’s leading universities, including Exeter, struck a £50 million deal to buy renewable energy directly from British windfarms. It is the first time that public sector energy users have come together to buy clean electricity.

* The capacity factor of a wind turbine is its average power output divided by its maximum power availability. Average onshore capacity factor has increased from 0.25 for projects installed from 1998 to 2001 to around 0.42 for projects built in 2014 and 2015. Offshore capacity factors are higher – on average up to 0.52.