Ocean Energy Europe (OEE) recently published an annual review of developments in the marine energy industry and it makes for some encouraging reading.

The report considers both tidal and wave energy technologies — the two most developed and viable marine power technologies being deployed. Although installed generating capacity for each type of system remains low, the projects that have recently been established, along with a few other developments, hint at a promising path ahead.

Marine energy technologies have been covered on Phlebas before, so for a primer on the industry and some of the key technologies involved, see ‘What About Marine Power?’.

Reaching the end of 2016, OEE report twenty one tidal turbines over 100kW were deployed in European waters — a total tidal stream capacity of 13MW. OEE also note that construction is underway on a further 12MW.

Without doubt, wave energy technology currently lags behind tidal energy. Though there are numerous pilot projects and demonstration units in the water, the technology remains nascent relative to the commercial status of some tidal projects (for instance, the likes of MeyGen described below).

OEE report thirteen wave energy devices of 100kW or more deployed at sea by the end of 2016 — a combined wave capacity of close to 5MW. Ten of these systems were deployed in the last three years. Six further projects totalling 17MW are under construction.

Notable Developments | MeyGen

Although three significant tidal projects were completed in 2016, one stands out: the MeyGen project. Already the largest tidal energy energy project built to date, MeyGen is slated for big things in the years to come.

Located in the Inner Sound of the Pentland Firth, in the far north of Scotland, so far just four 1.5MW subsea tidal turbines have been installed as part of MeyGen’s first phase (Phase 1A). But in time the developer behind MeyGen, Atlantis, aims to see the array extended to over 260 turbines with a total capacity of 398MW. Grid connection for the initial four-turbine array was achieved in December 2016.

Encouragingly, Atlantis has secured financing for the next phase of MeyGen: known as Project Stroma. This second phase will see a further 6MW installed via work expected to begin sometime this year. Build-out to the full 398MW is anticipated to commence shortly after the second phase.

It’s an ambitious target, but Atlantis are confident not only in the performance of their system, but also in its cost-competitiveness (meaning, its ability to produce electricity at a cost comparable with other means of power generation on the market).

Atlantis certainly couldn’t have chosen a more ideal location for such a project. The Pentland Firth holds a third of the UK’s estimated technical tidal potential of 29TWh.

For more insights on MeyGen see, ‘First Power Begins from Major UK Tidal Power Project MeyGen’; an article written by Phlebas and published in Renewable Energy World. The article includes an interview with Atlantis CEO, Tim Cornelius.

Another tidal project being established in the stormy waters of northern Scotland is Nova Innovation’s Shetland Tidal Array.

Although far smaller than MeyGen at just 200kW to date, its grid connection in August 2016 was a world first. Beginning later this year, three more 100kW turbines are to be added to the existing two. (More details on this project here, ‘Scotland Welcomes World’s First Grid Connected Commercial Tidal Power Array’ — also at Renewable Energy World.)

Notable Developments | Carnegie Wave Energy & CETO

On the wave energy side of things, one company rightfully deserves an article focussed on its endeavours alone. Australia’s Carnegie Clean Energy remains one of the most innovative companies on the renewables scene, let alone within the junior wave industry.

Previously Carnegie Wave Energy, the company adopted its new name after acquiring solar PV and battery storage microgrid company Energy Made Clean (EMC) in October 2016. That in itself was an exciting development, one reflecting Carnegie’s focusing in on delivery of solutions that pair wave energy generation with microgrids and energy storage — a coupling that may be expected to perform exceptionally well in remote island settings.

Carnegie is getting underway with just such a project on the Indian Ocean nation of Mauritius. There the company is planning a microgrid featuring multiple generation sources, including CETO 6 — Carnegie’s latest generation of wave energy technology, design of which was completed last year.

Carnegie say that CETO 6 units will have a 1MW power capacity and, “superior efficiency, lower capital and maintenance costs than any CETO product generation developed to date.”

You can read about Carnegie’s microgrid project in Renewable Energy World article ‘Mauritius Takes Great Step Forward for Wave Power, Microgrid Design‘, where Carnegie Project Manager Neil De Tisi states: “The Mauritius project will clearly show how islands can achieve very high penetration of renewables by using a combination of wave energy, solar PV, wind energy, battery energy storage systems and smart microgrid control systems.”

That the Mauritius project rolls together such a collection of clean generation technologies, alongside battery storage and a new desalination plant, marks the project out as unique and certainly one to follow. If it’s successful, there are many island and remote coastal communities that could benefit from the solution. Carnegie already have an eye on projects for Bermuda and the Seychelles.

CETO 6 will also soon be making its way to the UK. Last year, project development began on the CETO 6 Wave Hub Project — Carnegie’s first international CETO project which will be sited at the Wave Hub facility in Cornwall, south west England.

The project will unfold over two stages: the first involving installation of a single 1MW CETO 6 unit, and the second, extension to a 15MW commercial array. Both stages would be built some 16km offshore. Commissioning for stage 1 is slated for the end of 2018.

Australia’s total potential wave resource is estimated to be some five times the installed power capacity of the country

Final bit of news from Carnegie: in February they made an encouraging announcement about long-standing plans for the Albany Wave Farm, Australia.

The Albany project would be the first commercial scale wave farm in Australia. Built in stages, the wave farm would expand from an initial 1MW unit (presumably a CETO 6), to 20MW. Thereafter, the company have stated that “successful demonstration of the 20MW farm could in turn lead to a 100MW expansion.”

Notable Developments | Swansea Bay Tidal Lagoon

A quick mention goes to the Swansea Bay Tidal Lagoon project. Picking up attention this year, the project would be the world’s first tidal lagoon power plant. Located in Wales, the project fully permitted to 320MW and could be established by 2021.

For the time being however, the future of the project is uncertain. In order for the project to go ahead it requires agreement from the UK government that electricity it produces would be purchased.  The problem is that the electricity produced at Swansea Bay simply wouldn’t be price competitive (side note: capital costs for the project are estimated at £1.3 billion).

As The Economist points out, the so-called strike price the government would have to pay for Swansea Bay electricity would be about £123 per megawatt hour — far higher than strike prices the UK paid out last time it held a major auction for new renewable capacity in 2015 (see, Carbon Brief for insights on this matter).

Keeping in mind that prices would be lower in auctions held today, in the 2015 auction successful onshore wind projects averaged about £80 per MWh and even offshore wind power averaged £117. The predicted costs of power from Swansea are considerably more than the (exceptionally dumb) agreement of £92.50 per MWh the UK government made for Hinkley Point C nuclear power plant.

Still, proponents argue that as a flagship project Swansea Bay could demonstrate a novel renewable energy technology; one that could readily be scaled up to even larger projects around the UK that would generate electricity at lower costs in the future. Indeed, OEE have highlighted tidal lagoon power as a technology with significant potential for growth across Europe.

The project will harness tidal range energy which — distinct from tidal stream energy — involves utilising differences in sea level between high and low tides.

A tidal range power system works in a manner similar to how hydropower captures the energy of water rushing from an upper reservoir to a lower one. The concept involves creating a barrier containing turbines which generate electricity as water is forced through them at high and low tide. The barrier also allows for controlling the outflow of water after high tide.

Conceptually, tidal lagoon power is a form of tidal barrage, of the sort that have been in operation for decades. However, instead of a barrier locking off an estuary entirely, tidal lagoon schemes involve a ring-shaped barrier which creates an artificial lagoon within which water (read: potential energy) is held — the distinction carries several advantages, not the least of which relate to environmental impact. The Swansea Bay Tidal Lagoon project would feature a six mile wall embedded with 16 hydro turbines.

 

The Enduring Promise of the Ocean

The driving force behind investment into marine energy systems is the plain fact that oceans and seas represent an absolutely massive source of renewable energy. To tap that energy with technologies that are efficient and cost-competitive would be major win for renewables in the carbon war.

Looking forward, OEE highlight that studies forecast some 337GW of wave and tidal energy capacity could be deployed around the world by 2050. In Europe, there is potential for some 100GW by that same time; capacity that would provide some 10% of the EU’s electricity demand. Or put another way, power for some 230 million people. In the closer timeframe, OEE forecast European ocean energy deployment to reach a cumulative capacity of 850MW by 2020.

Without doubt, the development path ahead for tidal and wave energy systems retains significant challenges. As wind and solar PV power mature further still — pushing beyond the astonishingly low prices they have achieved already –, marine energy technologies have some catching up to do.

Nevertheless, the events of 2016 serve to remind that many remain committed to both flavours of marine power technology. That such a number of projects have gotten off the drawing board and into the water with full scale devices is encouraging. Many of these projects are phased, with initial stages featuring just a small number, or even one device — a reflection that in-water testing remains a key stepping stone on the road to commercial deployment.

All told, the industry continues to be an exciting one to keep a close eye on.