The vast potential of UK-based tidal energy

Tidal energy is approaching the stage at which it can be considered a serious alternative to non-renewable energy sources

The UK marine energy sector is experiencing big developments. The government’s energy bill has created new funding measures, and corporate investment has emerged just as new tidal technology testing is underway.

Trials of a new commercial-scale turbine at the European Marine Energy Centre (EMEC) in Scotland commenced in January as part of the Energy Technologies Institute‘s (ETI) Reliable Data Acquisition Platform for Tidal (ReDAPT) project. The £12.6m project was announced in 2009 and is due for completion mid-2014, when the turbine’s testing period ends.

Deployment of this project has been warmly welcomed, as until now the marine energy industry in the UK has developed on the back of government grants and some venture capital investment. This kind of funding is not sustainable in the long-term due to the lengthy gestation period of the technology: although, there is now a growing confidence that the machinery is close to maturity.

Wave potential
ETI has relied on financial support from its six private-sector partners: BP, Caterpillar, EDF Energy, E.ON, Rolls-Royce and Shell. Its public funds are received from agencies such as the Department for Transport and the Technology Strategy Board. Its latest turbine installation was carried out by Alstom, a French multinational conglomerate that recently acquired tidal turbine designer and manufacturer Tidal Generation Limited (TGL) from Rolls-Royce.

Larger corporate companies, such as Alstom and Siemens, have invested in similar technologies as they align with their corporate strategies and, more importantly, the businesses have the funding and enduring investment timeframes to support the projects.

Alstom’s new 1MW turbine was installed at the EMEC tidal test site in Orkney at the end of January. It was mounted on the same tripod support structure used to deploy the previously tested 500KW device, where it will remain for an 18-month trial period. There are high hopes for this machinery, as TGL’s 500KW turbine generated 200mw hours for the national grid between September 2010 and March 2012, demonstrating great potential.

Jacques Jamart, Senior Vice President of Alstom New Energies, said: “This new milestone installation in the development of tidal power generation technology is a step further towards the commercialisation of this new power solution.”

Tidal… is an inexhaustible supply of energy, is as predictable as the turning of the tide [and] requires no fuel

The aim of the ReDAPT project is to increase confidence in turbine technology. The current test will provide a wide range of environmental impact and performance information, while demonstrating the latest turbine designís efficiency. Induction of the turbine will demonstrate a new, productive, reliable design.

It boasts features that are as impressive as they are effective: an 18 metre rotor supports three pitchable blades, and the 150-tonne machine is buoyant, allowing minimal installation and maintenance costs. It operates at 40 metre depths with the ability to rotate to face the incoming tide at the optimal angle to extract maximum energy potential.

Jerume Pecresse, President of Alstom Renewable Power said: “This technology will optimise electricity production, limit maintenance constraints, and thus will help reduce the cost of electricity of this renewable energy source.”

It is anticipated that this, in turn, will accelerate deployment of marine energy technology in the UK, as there are currently many unexploited marine energy resources around the countryís coastline. The next step is to install pilot arrays prior to full commercial production.

This subsequent phase seems more promising, with the recent acquisition of financial support from the Department of Energy and Climate Change. A spokesman said: “We’ve more than doubled support for wave and tidal technologies from April 2013 under our Renewables Obligation scheme, and committed £28m of government support for testing facilities. Weíve also helped develop Marine Energy Parks, which are bringing together manufacturing and expertise to generate new innovation and accelerate the move to commercialisation.”

An additional development fund of £20m for low carbon technology has also been awarded to MeyGen and SeaGeneration Wales to test their innovative turbines in formations out at sea. Climate Minister Greg Baker said: “These projects will provide valuable insight into how best to harness the power of the sea and take us one vital step closer to realising the full potential of marine in our future energy mix.”

Jobs and power
MeyGen is using the investment to deploy a commercial array of 1.4MW tidal turbines, developed and supplied by Andro Hydro Hammerfest, at the Inner Sounds Pentland Firth site off the mainland of northern Scotland. These Scottish locations prove popular testing sites as Scotland boasts 25 percent of Europeís tidal energy potential, with the Pentland Firth and Orkney Waters hosting the worldís first commercial-scale leasing ground for marine energy.

The results from MeyGen’s turbines will be telling; Andritz Hydro Hammerfestís pre-commercial 1MW turbine was installed at the EMEC site in December 2011, but did not deliver any energy to the grid until February 2012. MeyGen has also applied for Scotlandís Saltire Prize Challenge – a clean energy grant worth £10m – to accelerate the commercial development of wave and tidal energy technology.

All this investment will be beneficial, as tidal turbines not only have the potential to deliver a significant portion of UK electricity ñ up to 2GW of deployment by 2020 – but the sector could be worth £6.1bn to the country by 2035, creating nearly 20,000 jobs.

Tidal appears to be a sensible energy resource choice for the UK due to the abundance of shoreline available to the island nation. It is an inexhaustible supply of energy, is as predictable as the turning of the tide, requires no fuel supply and has a smaller carbon footprint than many other energy sources.

But according to a recent RenewableUK report, the strike prices for the new Contract for Difference regime in 2017 pave the way to more tribulations for the marine energy industry. To attract more investors to commercial-scale tidal arrays, they will have to guarantee a strike price of £280-300/MWh by 2020, but realistically the prices may be as high as £320/MWh. This would look far less favourable to investors than the current estimated targets of £100/MWh for offshore wind and nuclear energy by 2020.

Emerging results from current tests may give more of an indication if tidal energy stands a chance at competing for investors against other renewables. However, EMECís Managing Director, Neil Kermode, has himself admitted that the company is facing challenges with grid capacity and connection charges and has stressed the importance of the momentum needed to overcome these obstacles.

For marine energy to be lifted from its status as an esoteric concept, the momentum Kermode is talking about needs to come from ongoing investments, with potential future backers following suit. Without them, the new tidal technological developments will be left stagnant and the UKís greatest potential source of renewable energy will continue to be left untapped.