A stiff south-westerly is leading the charge of waves onto the beach, pounding it flat in percussive beats. Overhead, the huge clouds that have unloaded intermittent heavy rain in the preceding hours have temporarily been scoured from the sky, a fragile truce of brilliant blue holding for now.
"I love the power of the sea,” says Deborah Greaves OBE, Professor of Ocean Engineering, looking out towards Great Mewstone, the small island standing half a mile offshore. “You can really feel its energy standing here, the way the waves crash onto the rocks.”
We’re standing on Langdon beach, a small stony shore beneath Wembury Point. The land was once home to a gunnery school, which closed at the turn of the millennium, the victim of spending cuts and technological progress. Much of it is now owned by the National Trust, which is returning it to a wild state, save for a small radar facility still operated by the Ministry of Defence. On the shoreline in front of us you can just about discern the outline of an old swimming pool, one whose holiday camp heyday of the 1920s has long been swept away by time and tide.
“I grew up here, and when I was a child we would spend a lot of time on this beach and swimming in the sea,” Deborah recalls. “We would head out onto the Mewstone in a rowing boat and explore. And on Thursdays, a plane would fly over the water, trailing a target, and the cadets at HMS Cambridge would fire the guns at it. It was incredibly loud.”
Nowadays, the ‘rush hour’ of cars going to and from the base has been replaced by dog-walkers and their companions strolling along the coast path. Deborah’s own dog, a Labrador-Springer called Freya, barrels into the surf to fetch a briny branch before returning to shore to begin its enthusiastic deconstruction.
“It’s been lovely to be able to come back here and share this with my family,” says Deborah, who returned to South Devon in 2008 when she joined the University. “I left home at 18 for my degree, and lived in Bristol, London and Bath. But I always missed the sea. When you’ve been brought up somewhere like here where you can always hear the sea, even at night, it draws you back. We were fortunate enough to be able to buy the house next door to where I grew up, and my mum is still living there now!”
A good deal had changed during those intervening years, not least the closure of HMS Cambridge. And those waves of Deborah’s childhood have now taken on added significance – they have become her professional focus.
Despite hailing from a family of the arts and humanities, Deborah – Head of the University’s School of Engineering, Computing and Mathematics, and Director of the Coastal, Ocean and Sediment Transport Laboratory – excelled at mathematics and sciences at school. By the age of 13, she had already set her heart and mind on becoming a civil engineer, and as a pupil of Coombe Dean (where she was a classmate of another future engineering professor – and colleague – Alison Raby) and then Plymouth College, she was not afraid to walk onto a construction site and ask for work experience.
“I liked the idea of working outside,” Deborah says. “And I was also attracted by the fact that you’re building something that is permanent and helps improve people’s lives.”
Deborah enrolled on the BEng (Hons) in Civil Engineering in Bristol, and after graduating in 1988, started her career at a design office in London, where she had the opportunity to gain experience on a number of projects including the development of the Jubilee Line Extension. After four years, however, she was looking for a new challenge, and so she decided to make a change. “I took a year out to travel around Australia and the world, and when I came back, I enrolled on a DPhil at Oxford,” she says. “I still had that desire to do something that was related to the sea and to the waves.”
But when Deborah got to Oxford, there were no wave tanks or facilities to undertake physical research. Instead, she developed a new skill, in computational fluid dynamics and wave modelling on computers – one that would influence the rest of her career.
Looking out to sea on a day like today, when the wind and tide create a confusing, ever-shifting landscape, you struggle to comprehend how a computer could even begin to predict its behaviour and characteristics. But for Deborah, physical and numerical modelling are complementary disciplines that inform and bring insight to one another.
“I enjoy working with computers and coding – everything can be perfect and idealised in the computer, which of course is not the case in the real world,” she says. “Being able to calculate using equations and visualise onscreen the beautiful patterns and shapes you get in wave structure interaction has always fascinated me. It is important to understand those elements, but to do so in conjunction with physical modelling. You obtain insight from the model, but you need the experiment to tie it to reality.”Deborah’s first academic post was at University College London, lecturing in mechanical engineering and naval architecture, before she moved on to the University of Bath in 2000. She had spent eight years there working in civil engineering and hydrodynamics of offshore structures, when a role came up at Plymouth focused around marine renewable energy. And with a family of three, and a chance to move into a new area of research, it was an opportunity she seized with relish.
“The University had a good reputation in coastal engineering, a long track record, built using the 20-metre wave flume in the Brunel Building,” Deborah says, “When I arrived, my first strategic project was to create a plan for new wave tanks designed for the marine renewable energy sector – that would ultimately lead to the creation of the COAST Lab. For the first time I was able to bring the two disciplines together, running physical experiments in the tank and then creating a numerical mirror on the computer.”
With Deborah’s arrival, the University accelerated its entry into the field of marine renewable energy research – the most embryonic of the elemental green energy forms. In 2011, it launched the country’s first MSc programme devoted to the subject, and the following year it opened the Marine Building, with its state-of-the-art wave tanks and flumes designed to be used by students, researchers and industry.
Major research successes followed, funded by the likes of the Engineering and Physical Sciences Research Council (EPSRC), Horizon 2020 and Innovate UK. They included the ￡2 million, ten-partner European project called SOWFIA, which examined how wave farms could operate within EU directives for environmental conservation. Soon, the University was invited to become a member of the Supergen consortium devoted to marine energy, led since its inception from the University of Edinburgh, and it then hosted its first annual assembly
to be held south of the border. Deborah also became the founding Chair for PRIMaRE (the Partnership for Research in Marine Renewable Energy), a network of marine energy experts based in the region, including universities, research laboratories and industry conduits such as the South West Marine Energy Park.
But despite the best endeavours of government, industry and research partners such as the University, marine renewables – whether generated by waves or tides – have proven to be a brutally difficult endeavour. On a day like today, it’s not hard to see why.
“What is very apparent when you come to a beach on a windy day is the immense power of the sea,” says Deborah. “And it does not stop; it is not just one impact, but it keeps on going and going. I have come to this beach for many years and the shape of the cliffs is constantly changing. Every time there is a big storm you see a bit more of the cliff eroded away. So to design a wave energy device that cannot merely survive but perform reliably is an immense challenge. There are no half measures to survive in this environment.”
It is just seven miles from Wembury Point to the University campus, but the surroundings – and conditions – could hardly be more contrasting.
We’re standing beside the large wavegenerating pistons of the Ocean Basin – the magnificent swimming pool–sized facility at the heart of the Marine Building. Looming above us are several wooden structures that are to be used in the installation of wind power in the COAST Lab – the facility that coordinates the research and development work at the heart of the University’s mission to support marine renewables.
But the object of our attention is not the Ocean Basin, nor the smaller coastal tank elevated above it. Instead, it’s the relatively diminutive, snooker table-sized portable tank – one that Deborah is operating via a Perspex wedge. Pumping it up and down, she sends a cascade of small waves through the tank, lighting up LCDs as different wave energy devices are triggered.
The range of devices on display speaks volumes for one of the key issues in the marine renewable energy sector today – namely, the lack of convergence around an agreed standard or design. “The challenges with wave energy conversion are clear,” Deborah says. “Devices such as Pelamis (which had previously been tested in the COAST Lab) and Oyster reached full demonstration on the sea, but neither was successful enough to become commercially viable. And one of the contributing factors was the way they were funded, where they were under pressure to go to large-scale demonstration too soon. It’s very expensive to demonstrate something at sea and very public when it fails, and to some extent the wave energy sector is still processing these two high-profile failures.”
Deborah says that a more incremental approach is needed, like the one being trialled by Wave Energy Scotland, where developers are encouraged to move from the wave tank to the sea and back again. And she also believes that a little more patience and perspective are required.
“Wave energy gets a hard time,” she says. “If you think about how wind power developed, it was initially through small, domestic-scale sites onshore, and it was then able to incrementally increase in size. Now you have convergence of technology, price reduction, economies of scale, and large players involved in manufacturing and running the offshore wind farms.
“With wave energy, you are under so much pressure to prove straight away that your concept works,” Deborah continues. “And there is no such thing as a ‘small sea’. Even if the conditions are relatively benign or you create a nursery area, every now and then a storm is going to come along. You have to contend with all of this while at the same time developing a new technology that has to compete with the cost pressures that the success of wind has created.”
In 2018, the government unified the three hubs supporting offshore wind, wave and tidal power with the creation of the Supergen ORE (offshore renewable energy) Hub. Deborah was appointed as its lead – capping a remarkable 24 hours during which she was also made Head of School. With a ￡9 million project fund, and the support of industry and a range of universities, Supergen ORE is now working to facilitate the sharing of knowledge and expertise between the sectors.
“We need to think about where we have to get to,” Deborah says. “If we are to meet our targets to reduce greenhouse gas emissions to net zero by 2050, then we need a diverse energy mix. That means both on- and offshore wind, but also solar, tidal stream and wave energy. You can’t simply rely on one because environmental factors will dictate when they’re available."
To demonstrate, Deborah reduces the frequency with which she operates the tank, creating a longer form of wave. Now, a different device is sparked into life – an oscillating water column that reacts to the changes in air pressure caused by the waves passing beneath its tube.
“Many people do not understand the differences between wave and tidal stream energy,” she says. “But both are rooted in the basic concept of water movement being converted into electricity – and that is something we can demonstrate and communicate to people.”
And that brings us to the raison d’être for the tank – outreach and communication. Designed by technician Kieran Monk, the tank has been used for a number of events, including the renowned Green Man Festival in the Brecon Beacons, Wales, last summer. Kieran, Deborah, Supergen ORE’s Kirsty Henderson, and a team of PhD students took their place in the marquee in ‘Einstein’s Field’ as part of the science outreach programme, and had 1,200 people pass through, including families, teachers and political lobbyists.
“We had lots of activities that the young children could get hands-on with, and seeing them become inspired was fantastic,” says Deborah. “This is obviously a very visual device, and very accessible to young children, who just love to make waves, get the wave energy devices working, and see the lights come on. But you can actually talk about some quite complicated processes going on in here, and seeing them relate that to what they have learned in the classroom about electricity and energy was very exciting. If you are talking to a young girl of ten about this, it can open up the idea of a career in engineering. And what’s equally revealing is seeing the reaction of the parents.”
Deborah and Kieran using the tank to explain oscillating water columns - a type of wave energy converter that harnesses energy from the movement of seawater.
Inspiring women to enter into engineering is a motivational cause for Deborah. As the head of a male-dominated school, she is very conscious that many of the initiatives to encourage greater participation in STEM subjects have simply not translated into a more diverse mix in the average undergraduate cohort. So she is working to create a more inclusive environment, including through the introduction of new objectives for the leadership team. On a national level, through the Supergen ORE Hub, she also has a specific remit to oversee efforts to provide research leadership and to be a beacon for equality, diversity and inclusion.
"When I did engineering at school, I benefited from being part of the WISE (Women into Science and Engineering) programme, and a push at that time to get more women into STEM subjects,” she recalls. “But the proportion of girls on undergraduate courses just hasn’t changed. It’s a really big challenge to get girls to be more engaged with engineering and think of it as a career. I think the way we talk about engineering traditionally in the general public is very narrow. We do not understand the different opportunities, aspects, skills and characteristics needed in engineering in order to come up with those very important solutions for society – going through the green industrial revolution or combating climate change.
”It’s beyond a simple gender issue," says Deborah. "Engineering must draw upon a much broader section of society if it is to include all of the voices and ideas needed to engineer solutions for the future."
For Deborah, the author of more than 180 research papers – with ￡20 million in research funding on her CV, and a litany of awards including an Officer of the British Empire in 2018 and a prestigious Fellowship from the Institution of Civil Engineers – it is the future that is energising her most of all.
Artists impression of the new Engineering Building
“We’re following the same vision as the COAST Lab,” Deborah says. “In that we’re bringing together everything that we need to be successful – teaching, research and collaborating with industry. The facility will draw in those industries that will employ our students, and whose influence will keep our teaching relevant and up to date. And it will enable co-location of activities and multidisciplinary collaboration; along with our new School of Engineering, Computing and Mathematics, it will help create a convergence of the digital revolution with the environmental.”
The engineer of the future, Deborah says, will be better at understanding how big data might lead to improved bridges or wind farms. And that confluence of skills might also help to redress the gender imbalance of engineers in the UK. Deborah’s eyes sweep around the COAST Lab, as if to remind herself of how far things have come, and of the path that lies ahead.
“Whenever you build something on this scale, there is an element of uncertainty as to whether it will be a success,” she says. “In fact, it is often pretty terrifying along the way. But the difference you can make is phenomenal, transformational. And that is what we hope to achieve with the new Engineering and Design Facility.”