Going against the flow

Elaine Maslin

October 30, 2017

Record numbers of marine energy devices are generating record amount of power in Scottish Waters, but the sector has been knocked back in its bid for support. Elaine Maslin reports.

Timing is everything, they say. For the UK marine energy sector, it’s proving a challenge.

SR2000 alongside a multicat. Photo from Scotrenewables.

In many ways, the industry is having one of its best years. The largest number of marine energy devices are in the water, including the first arrays, power production milestones being recorded, and cost reduction potential demonstrated.

Yet, for an emergent, pre-commercial sector, which has had significant support from the EU, the UK’s exit from Europe isn’t welcome, especially at a time when the UK Government has pulled support for marine renewables, with no contract for difference (CFD) – a support mechanism – offered in the latest round.

With the cost of offshore wind now pegged as low as US$76/MWh (£57/MWh) (the lowest price agreed in the latest CFD for offshore wind), “Westminster thinks it doesn’t need any more renewables,” one commentator said during Scottish Renewables’ Marine Energy Conference in Inverness in September.

With there no longer being a green premium – i.e. you can no longer expect funding or support, just for being “green” – a different argument needs to be made for marine renewables, such as supporting the UK’s industrial strategy or community benefits, the conference heard.

One of the challenges the industry has faced, in order to get funding, is to demonstrate an ability to reduce costs. Yet, the tidal industry has just reached the point where it’s able to set a baseline, from which it can reduce costs as it builds out, and has reached the stage where it’s proving reliable power generation capabilities, says Andrew Scott, CEO of Orkney-based tidal energy firm Scotrenewables.

To put it another way: “They’re about to pull away the punch bowl just as the party begins,” says Chris Harwood, of Sustainable Marine Energy, a wave energy firm now also offering anchor and mooring technology as a way to diversify.

“We are dismayed at the lack of vision on the UK level,” Hardwood told the conference. “Over 15 years, there’s been a lot of good will and investment and we are starting to see that [improvement] curve, even at raw level generation. Right when (we’re) having technical success, [they are] removing investment mechanism for that to keep happening. This is a story we have seen before. In early wind, Germany and Denmark kept [their] policies in place, which means Denmark has people employed [in offshore wind].”

Robert East, UK Development Manager for “open-hole” tidal energy firm OpenHydro, says the challenge is to persuade politicians that the industry is worth backing, by focusing on gross value added and jobs for the UK, alongside continuing to build operational experience and seeking routes to market.

It can be done

It’s not all gloom, however. It wasn’t that long ago that few would’ve thought offshore wind could reach £57/MWh. “If they [offshore wind] can do it, it’s logical that we can, too,” says Andrew Smith, managing director of Glasgow Consultancy Deja Blue (previously head of Scottish Enterprise’s Renewable Energy Investment Fund).

Neil Kermode, managing director at the European Marine Energy Centre, (EMEC), on Orkney, is also positive and points out that there are more devices in the water than ever this year.

“I don’t think I’ve been at a conference when we have had so many devices in the water,” Kermode says. “This is what happens when you stay with the program.” The EMEC test site opened in 2004. Since then, it has had 30 devices tested at its sites, from 19 developers across 10 countries.

“The first job was getting something to stay still in the water,” Kermode says. “Next was to generate power. And then to generate for longer periods. That’s about polishing all the details, so that no single component holds back the program. It’s about repetition.”

There’s plenty of other work ongoing, including looking at different types of materials, coatings, biofouling and corrosion protection, as well as cables and how they behave in water.

“It’s about how to improve performance of the machines,” Kermode says. “Simplify, make them more robust or build heavier. These are the things people are grappling with, looking at where can we economize.”

The success of EMEC is borne out by the fact that devices there are producing more electricity than is needed on the island. To make use of the excess power, EMEC has opened a hydrogen plant, which will initially help power visiting ferries via fuel cell, while they’re in port, but, ultimately, the hope is that this could provide enough hydrogen to power the ferries around the islands, all from wave and tidal energy.

Atlantis Resources

Artists' impression of MayGen

Atlantis Resources has been paving the way – in both deployment and finding finance (notwithstanding the recent lack of CFD). The firm’s MeyGen project in the Pentland Firth achieved a record for monthly production from tidal stream power in August this year, with 700MWh. That was with two Andritz Hydro Hammerfest turbines. A third was reinstalled in late August. Atlantis’ own AR1500 turbine was due back in the water at the end of September, taking the MeyGen Phase 1A to its 6MW capacity from the end of Q3.

The firm’s Phase 1B (Project Stroma), which has EU funding, was approved last December and will see a further four turbines deployed. The turbines will be provided by Marine Current Turbines (MCT), a company bought by Atlantis from Siemens in 2015, and they will have larger diameter rotors and optimized turbine power ratings. Drilled foundations will also be used, instead of the “material intensive” gravity foundations used in Phase 1A.

Whereas Phase 1A had separate cables to shore for each turbine, Phase 1B is looking at how a single export cable could be used. Wetmate versus drymate connectors are being assessed, as well as learnings from the MCT project at Strangford Lough, Ireland.

Phase 1C would see a further 49 devices installed (73.5MW capacity), starting in 2019, with full power export from 2023. Phases 2 and 3 then have the potential to build out to 398MW capacity.

Despite the firm’s success to date, it was critical of the lack of UK funding for marine energy. Atlantis made a bid in the CFD auction round, which forecast a two-thirds reduction in the level of revenue support required for Phase 1C, versus that enjoyed by the first phase of the project. Atlantis also pointed out that there are funds available for further contracts awards, because 40% of the US$285.2 million [£290 million budget] for the recent auction round was not allocated through the competitive process.


Andrew Scott. Photos courtesy of Paul Campbell/Highlands and Islands Enterprise.

Scotrenewables has been chalking up milestones with its 2MW SR2000 tidal energy device. The floating, moored structure, which supports two, 16m-diameter rotor, 1MW turbines, with the generators and controls accessible inside the floating substructure, via ribs from shore, is being tested at EMEC.

Earlier, the 500-tonne unit, built at Harland & Wolff in Belfast last year, had generated over 18MWh within a continuous 24hr testing period, reaching 40% capacity: “a performance level which matches established offshore wind turbines,” says the firm. The device was taken to shore in summer, due to a problem with a cable, but was back generating from 9 August, producing 300MWh over 30 days with a couple of outages – caused by two creel (fish basket) buoys in the rotors. It also achieved 120MW over a seven-day period. It then broke its own record, producing 20MWh in a 24hr period late September.

Scott says the unit is easy to install with small vessels, i.e. multicats. In under 30 minutes one can be installed with 30-tonne bollard pull vessel. An onboard winch enables it to self-install, in 1-1.5m wave height conditions, once the recovery line has been picked up.
Scotrenewables’ is looking to improve performance further through the EU-funded Horizon 2020 project, “FloTEC.” This will see the rotor blades increased to 20m-diameter and composite materials developed, with project partners EireComposites. Scotrenewables says this alone is projected to increase annual yield from the turbines by more than 50%.

Nova Innovation

 Simon Forrest

In 2016, Nova Innovation built a three, 100kw-device tidal energy array at Bluemull Sound between the islands of Unst and Yell, Shetland. It now has Horizon 2020 funding to extend the array with another three devices and add a smart grid with battery storage. Simon Forrest, the firm’s CEO, says the philosophy is about starting small.

The Nova M100 device is described as a flat pack. It took two months to the first device, including cables, substructure, ballast etc. “On the third it took six days,” says Forest, “with 70% reduction in cost.”

The extension project will look at device spacing, moving the devices around and assessing hydrodynamic forces. An energy storage system will also look at how to curtail production when demand is low, but make more available when demand is high, so that it would in effect create a base load power, in combination with an intermittent producer like offshore wind.


Sue Barr

Sue Barr, external affairs manager, OpenHydro, says: “We are at a critical point. We have to move from technology development to industrial development. If we can show this can be an industry going forward, that could be a strong signal to drive revenue.”

OpenHydro has a 2MW, seafloor based (on a tripod gravity base) bi-directional permanent magnet ring motor, 16m-diameter tidal turbine – the so-called open-hole device. It’s transported and installed with a purpose built, modular barge. The firm is part of Naval Energies Group (previously DCNS), a majority French state-owned firm.

Having settled on a design, 2014-16 saw the firm focus on a new power convertor, and its control systems. Now it has demonstration projects, i.e. Cape Sharp Tidal (two 2MW devices in Nova Scotia), another two at Paimpol–Bréhat in France, and a single device in the Goto Islands, Japan. Barr says the firm has a 900MW pipeline of projects.

Significantly, the firm is looking at assembly facilities on an industrial scale to reduce costs and has an EU Horizon 2020 grant in place to help this work. It wants to start out with a 25-turbine a year facility, extendable to 50, with the first turbine expected to be delivered off the production line in Q1 2019. A site hasn’t been chosen yet.

And the rest

Meanwhile, companies without their own technologies are seeking to develop sites. Ireland-based DP Energy got consent to develop the West Islay Park, a 30MW tidal energy project, which it says could take a range of devices, from seafloor mounted to floating devices.

There’s also plenty of other work ongoing. Vicky Coy, project manager marine at the Offshore Renewable Energy Catapult (one of a number of not-for-profit technology “catapults” in the UK), says this time last year the catapult had 30 projects ongoing, with a third on wave and tidal. Now there are fewer, but they’re larger and include blade turbulence in the water, a tidal harness, RECODE (a wave energy project), and an involvement in EnFAIT on the Shetland Array with Nova Innovation.

Hayman says the industry is learning by doing. For Kermode, the industry is progressing. “Over the next few years we will see some designs run for longer without intervention. We are also going to see small groups of small arrays, 2, 3, 5 machines, start to happen. It sounds straight forward, but it’s not trivial. They’ve to consider how connect them, how does failure of one affect the others, how intervention on one affects others. Fundamentally, provided there’s support from government, we expect to see continued development.” 

Further Reading

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With waning support for marine energy in the UK, Sustainable Marine Energy decided to head East. Elaine Maslin reports.