Big data, marginal gains, ‘total control’ – what’s the future for improved efficiency in renewable energy engineering?
Published: 06 October, 2021
Paul McKeever, head of electrical research, Offshore Renewable Energy (ORE) Catapult
The renewable energy sector within the UK is an engineering success story, putting our industry at the forefront of global activity in this area.
For decades, UK-based innovators have worked to create some of the world’s first wind turbines, making the offshore wind sector an established contributor to UK and global net-zero targets. This means the UK is set to reach 40GW of offshore wind capacity by 2030, enough to power every home in the country.
So does that mean our work is done? Are wind turbines classed as a finished engineering achievement?
Far from it. Part of our work, and that of the innovative companies we support, is now about drilling down into further potential – analysing the performance of wind turbines and finding out just what can be done to further increase their efficiency and overall performance.
This is then feeding into our work in emerging renewable sectors such as tidal stream and wave energy, which are set to positively impact our clean energy production.
One of the projects we are working on in this fascinating area is TotalControl, a €5 million four-year collaborative project funded by the European Union through its Horizon 2020 programme.
The project is investigating how operators can revolutionise the control of wind turbine ‘yaw’ (the alignment of the wind turbine nacelle with the wind direction) and pitch (the operating angle of the wind turbine blades), amongst other factors, to find the optimum set up to increase power at a lower cost of production.
At present, in a typical offshore wind farm, each wind turbine’s control system operates in near-total isolation, adjusting its own individual yaw and pitch. TotalControl is one of the first projects looking to enable the entire fleet of turbines to orchestrate their yaw and pitch in harmony with each other, taking into account the effect one turbine’s operation has on the wind flow or ‘wake’ coming through to another.
To put it simply: each turbine is currently playing its own tune within a wind farm with limited reference to the other players (turbines). The philosophy of TotalControl is that the turbines should begin to do more as a collective within the wind farm; in effect, play together more as an orchestra.
Each turbine, and indeed the whole wind farm, is also producing an abundance of big data. While turbines are generating clean electricity, a complex network of sensors and systems are generating and logging information about the condition and performance of everything involved – from the turbine’s blades and drivetrain down to its bolts and even the heart rate of the technicians sent to make repairs.
All of this data presents huge opportunities for us to exploit the insights it gives us to inform innovative changes.
Wind turbines are not the only machines at work off our coastlines. Marine energy is a hotbed of innovation, with engineering experts at work within the UK to take the lead in what is set to be the next big player in the renewables field – tidal stream energy.
UK waters hold roughly half of Europe’s tidal stream resource and current tidal technologies from 30 key sites could supply 6GW of power[1] (enough to power almost 5.6 million homes)[2]
The sector is ready for commercialisation, with sites such as Nova Innovation in Shetland and Meygen in Scotland operating high performing, grid-connected tidal arrays.
What’s exciting is our ability to take the learning from projects such as TotalControl in the wind sector and use this to inform our thinking around engineering efficiency for tidal.
There’s a lot we already know about the power of the tides. We know that they are predictable – up to 100 years in advance– something no other renewable energy source can offer, and something that we see as crucial in creating a sustainable green energy landscape that can end the reliance on fossil fuels when the wind doesn’t blow or when the sun is not strong enough.
We know that the UK is a prime location for the sites that will harness this energy, that 80% of the current supply chain is right here on our shores and that it has the potential to be realistically affordable in a far shorter timeline than we saw with wind.
But there’s a lot we don’t know – we don’t know the tidal effects on size and shape of waves and how they dissipate, the effect of tides and devices on the seabed, and the details around shear and turbulence. As a result, engineers are working in partnerships within the UK and across Europe to investigate how tidal stream arrays can take the learning from projects such as TotalControl to create their own beautifully ‘harmonic orchestras’.
The €20 million EnFAIT (Enabling Future Arrays in Tidal) project, for example, is working with Edinburgh’s Nova Innovation, the world’s first developer to connect tidal turbines to the national grid. It is investigating how tidal turbines should be moved and positioned within an array for optimum production. In the same way that wind turbines are being moved to understand their interaction with each other and with the environment, this is happening with tidal turbines.
The comparison between wind and tidal is a significant one. While the wind sector is pursuing this research years after it became mainstream, tidal power has learnt the lessons of the wind pioneers and is doing this optimisation work now.
This level of refinement based on understanding is far ahead of the journey we saw with wind because our knowledge is so much greater. For example, Nova’s latest 100kW direct-drive turbine (M100-D) is the fourth to be installed in the Shetland Tidal Array and no longer requires a gearbox. Fewer moving parts make it more reliable, and the period between maintenance intervals has been extended from one to two years.
The new turbine, ‘Eunice’, was deployed in October 2020, and it will cut the cost of tidal energy by 30%. A further two direct-drive devices are set to be installed in 2022 and will be the subject of continued testing. Meanwhile, the ELEMENT project is introducing behavioural modelling to Nova’s turbine control systems, a move that could reduce cost by 17 per cent.
This research and innovation is the tip of the iceberg. We also have UK-based projects run by companies such as Floating Power Plant that are researching and testing the combination of wind and tidal turbines on floating turbines. The insight, creativity and engineering excellence here should not be underestimated. The team have used data from across these sectors to establish what they believe to be the optimum hybrid model.
This is data insight and engineering mastery at its best – right here in the UK and offering years of potential for our job market, our economy and our chances of creating a greener future, enabled through innovation.
Levenmouth test Turbine
