Negotiations deemed “frustrating” between Alex Salmond and David Cameron over Scotland’s mooted independence are the talk of the town in Edinburgh. But discussions of a seemingly more productive sort are ongoing for wave energy firm Pelamis Wave Power, which believes it is on the verge of signing up the big commercial partner that will take its technology to the next level.
Scotland makes a natural home for renewable energy companies, with an ambitious – and sometimes derided – target of the nation consuming 100% renewables by 2020. Richard Yemm, the mechanical engineer who founded Pelamis 14 years ago, delivers a robust defence of the goal. “It’s slightly misleading, because we’re connected to the UK and the target is for average use throughout the year. There will be days when we are supplying renewable energy to other parts of the UK, and days when a bit of conventional is coming back to us. But it shouldn’t be dismissed out of hand. We have only 10% of the electricity usage of the UK, and so the target is deliverable technically – as long as we’re part of a bigger grid.”
At the docks at Leith, where Pelamis has a cavernous assembly area, dry dock, and headquarters, Yemm talks about his plans with an enthusiasm that you can imagine must have sustained the company from the drawing-board of a PhD student at Edinburgh University to its position today. The rationale is simple, he says. “We’re doing this because there are attributes to wave that are different from other renewables. If you think of the ocean as a giant battery that’s constantly being charged with wind energy, and that you know is coming and can be forecast, it makes for a dense source of renewable energy.
“Every step you take on the beach on the west coast of Scotland marks enough power on average through the year to power 100 homes – it’s an extraordinarily powerful resource.” That resource is available to many more countries than the UK: nations with coastlines 20-60° either side of the equator have the greatest potential. A nation such as Japan, with concerns over nuclear power and energy security, would be primed to benefit from wave power, Yemm suggests. So companies developing the technology now could tap into global demand.
Pelamis, which has more than 40 staff, claims a series of firsts, including being the first wave energy company to supply electricity to the grid from an offshore wave energy converter and supplying the machines for the world’s first multiple converter wave farm in Portugal. Perhaps most importantly in terms of the UK, the company had sold two of its machines to utilities E.on and ScottishPower Renewables: “We’re the only firm in the sector to have generated sales from utilities buying pieces of equipment,” says Yemm.
The E.on machine is being tested off Orkney. Swedish energy firm Vattenfall is expected to order another Pelamis machine shortly. There are several stretches of sea leased from the Crown Estate and destined to be developed with Pelamis’ wave power systems. And a commercial partner is being sought as the company outgrows its venture capital backing. “We’re in the middle of the process with Ernst & Young to find a big strategic partner. We’ve got the technology, we’ve proven it works, and we’ve proven there’s an appetite among utilities to buy it,” he says.
“What we need now is a strong company with complementary skills, to take machines from pre-production prototypes and turn them into the finished product. We’ve been selective. We’re looking for an experienced company with a real drive to get into wave energy, so it won’t be a fringe activity.”
Six Pelamis machines have been produced by the company to date. The four first-generation machines were deployed off the coast of Portugal and in Scotland. This allowed the team to develop the designs for the second-generation machines bought by E.on and ScottishPower Renewables.
These machines have three times the energy yield of the prototypes but are only 40% more expensive, says Yemm. Rated at 750 kilowatts, they’re made up of five tubular steel sections linked by universal joints which allow flexing in two directions. The second-generation machines are 180 metres long and float semi-submerged on the surface, always facing into the direction of the waves.
As waves pass down the length of the machine and the sections bend in the water, the movement generates electricity via power take-off units (PTUs) housed inside each joint of the machine tubes. The PTUs are driven by hydraulic cylinders at the joints, which resist the wave-induced motion and pump fluid into high pressure accumulators, allowing power generation to be smooth and continuous, according to Pelamis. The power is transmitted to shore using standard subsea cables and equipment.
There’s nothing particularly special about the components used in the wave power machines, says Yemm. Indeed, the intention has been to use commonly available parts and materials wherever possible. “For example, the hydraulic rams are 200-millimetre bore, which puts them smack bang in the middle of the industry standard,” he says. “It’s better to take proven components and build a new assembly out of them.”
Another guiding principle was to work as much as possible on the machines on dry land, a model borrowed from the oil and gas industry. “We don’t build anything offshore. In that sense, our machines are like ships,” he says.
The machines are anchored with a slack mooring to the ocean floor and can move about within a 30-metre radius. Onboard GPS systems can pinpoint the machine’s location, were it to somehow lose its moorings. The machines also comply with the Coastal Protection Act and have navigation marks.
They’re designed to be survivable in rough seas, and to enable both installation and removal for maintenance to be performed as quickly as possible. This means that a machine could operate through the winter when conditions are rough. “It takes under 90 minutes to install a Pelamis second-generation machine in waves of up to two metres, and it can be removed for maintenance in 15 minutes in three-metre
waves,” says Yemm.
He hopes that many hundreds of Pelamis machines could be deployed around the country in the coming decades, and further afield as well. For one thing, he says, they are less likely to be objected to by residents than technologies such as onshore wind: “There’s the old acronym ‘nimby’, but we’re working to a planning principle that was recommended to us, ‘banana’ – build absolutely nothing anywhere near anyone. We’re out of sight and out of mind.”
Costs for wave energy are coming down. First-generation Pelamis machines generate electricity at a relatively high 80p per kilowatt-hour. “That’s the harsh reality of developing new technology,” says Yemm. “You start off thinking steel costs x per tonne, and hydraulic rams cost this much. But by the time you’ve engineered and tested the complete machine and worked out that you’re not going to get as much power as you predicted, you end up in a different place.”
The second generation, though, brings costs down to around 30-40p/kWh – in line with solar energy. As a starting price for small, 10-megawatt projects, that is unprecedented in the energy sector, he claims: “In today’s money, coal cost about £1.50/kWh when it started. Don’t even ask me what the starting cost for nuclear power was.
“We have a stunning starting point and a clear trajectory for cost reduction to the level of offshore wind and further, to around 10p/kWh, which gives us parity.”
Yemm, who studied under the distinguished engineer and academic Stephen Salter while completing his doctorate at Edinburgh, financed the early days of Pelamis through grants and the generosity of friends and family.
He also ran a production line making wind turbine damper units to stop blade vibration, which brought in the seed capital that kept the company running in its early days. He says it’s been quite a job to keep the money flowing in since then, but is proud that his firm has managed to do a lot with the capital.
Asked whether he has engineering heroes, he says: “Britain and Scotland have a fantastic engineering heritage. But there haven’t been a lot of engineering successes coming out of the UK recently – we hope Pelamis is going to be a reversal of that. For example, with wind energy, Scottish and UK companies led the first stage of development, but we failed to commercialise it. It’s disappointing that we’re importing technology that could have been exported from Britain.
“That said, the politicians have finally put two and two together: renewable energy is about carbon dioxide reduction, but it’s also about delivering economic growth and jobs for the country.” he adds. That should create some waves in Westminster.