The UK can depend on tidal stream predictability

Richard Arnold, policy director at the Marine Energy Council, highlights the potential value of predictable tidal stream energy to a diverse generation mix as he calls on the government to maintain ring-fenced funding for the technology in the next Contracts for Difference auction round.

The UK energy system saw a record-breaking day on 2 November as wind generation exceeded 20GW for the first time, beating the 19.93GW record set in October, which itself broke the 19.91 GW record set in May of this year.

Record-breaking wind generation will be a welcome reoccurrence as the UK ramps up its wind capacity to 50GW by 2030.

The following day wind generation fell below 2GW with the shortfall covered by interconnection and gas-fired power generation. Energy security in a net zero world requires a diverse energy generation portfolio, so when the wind isn’t blowing or the sun isn’t shining the shortfall can be addressed by renewable and low-carbon options rather that fossil fuels.

Tidal stream energy is an entirely predictable, renewable firm power resource that is perfectly positioned to play that role. The technology harnesses the earth’s gravitational relationship with the moon and sun via turbines in our seas, turning the ebb and flow of tides into electricity.

The UK government demonstrated international leadership in setting a tidal stream ringfence in the last renewable auction. The 40MW secured in Contracts for Difference (CfD) Allocation Round 4 (AR4) is a vital step towards realising the UK’s 11.5GW of practical tidal stream capacity.

The government is currently considering the parameters of AR5 and it is crucial that the success of AR4 is built upon through maintaining the tidal stream ringfence. In response to a recent parliamentary question, climate minister Graham Stuart MP said that the tidal stream industry needs to demonstrate cost-efficiency and proof of scalability.

On the day of the minister’s response, the Offshore Renewable Energy Catapult published a report which demonstrated the ability of tidal stream energy to meet those tests.

Tidal stream is following in the footsteps of wind and solar in its cost reduction pathway

The report found that through economies of volume, scale and maintaining current learning rates, the cost of tidal stream energy will reach £78/MWh by 2035 (significantly cheaper than new nuclear) and fall below £50/MWh by 2050.

The £178/MWh strike price secured in AR4 represents roughly a 40% reduction in the levelised cost of energy (LCOE) from 2018 levels. By maintaining the ringfence the UK government will support investor confidence, grow supply chains, and guide tidal stream energy down the cost reduction curve.

However, LCOE fails to capture the full benefit of tidal stream to the UK’s energy system, economy, and security. Project EVOLVE found that 13GW of marine energy (tidal stream and wave energy) by 2050 will lead to an annual reduction in dispatch cost of £1.03 billion per annum. This reduction in dispatch cost is the result of a more consistent renewable energy profile when including marine energy within the generation mix, leading to lower requirements for peaking plants, energy storage, and electricity imports through interconnectors.

The journey to the most cost-effective net zero energy system is not paved solely by renewables with the lowest LCOE today. We need to invest in the technologies of tomorrow.

Tidal stream energy will benefit communities across the UK

Tidal stream energy will support long-term, green employment opportunities as turbines, blades and support structures are being built in the UK. This technology supports 45 jobs created per megawatt deployed in the UK (comparatively higher than other generation sources).

For example, Orbital Marine Power’s O2 device was delivered with over 80% UK supply chain spend. The O2 was designed in Orkney, built in Dundee with steel from Motherwell, blades from the Solent, anchors from Wales and hydraulics from the Midlands.

This high UK supply chain content continues throughout the operational life of the plant. In the first 18 months of operation of Nova Innovation’s world-first offshore tidal array in Shetland, 98% of supply chain expenditure went to UK companies, with 60% going to companies in the Highlands and Islands region. This highlights the key role tidal energy can play in regional economic development.

The Resolution Foundation recognised the potential role of tidal stream energy in supporting the levelling up agenda in its Economy 2030 report, noting technologies like tidal stream ‘are not only likely to generate relatively high national economic returns, but also have the potential to contribute to regionally balanced growth.’

Levelling up with tidal stream energy will also position the UK to benefit from growing export markets and support green Global Britain aspirations.

Local supply chains, international markets

These opportunities are already being seized by companies at the forefront of tidal stream energy. Scottish-based Nova Innovation is deploying a 15-turbine array in Canada and exploring opportunities in Indonesia; Proteus is developing a 12MW array in France; Simec Atlantis has deployed a turbine in Japan; China is currently piloting projects; and Minesto will deliver 40% of the Faroe Islands energy demands with its tidal stream kites.

The Policy and Innovation Group from the University of Edinburgh estimates that through exporting goods and services worldwide, tidal stream energy could be worth £17 billion gross value added (GVA) to the UK economy by 2050. With the world-leading expertise in the UK, which is home to the most advanced tidal stream technology providers, they estimated that the UK could capture 25% of the global market through exports.

Maintaining the ringfence will also support international investment into our energy system and the UK. Spanish company Magallanes was one of the successful bids into AR4 and will deliver a 5.5MW project in Anglesey.

Realising the UK’s tidal stream energy potential

In the Energy Security Strategy, the government committed to aggressively explore the renewable opportunities afforded by tidal energy. To realise those opportunities the government should implement the recommendations in the Catapult report, namely:

• Maintain ringfenced support for TSE in AR5 and beyond
• Set a deployment target of 1GW by 2035
• Work with the industry to speed up the consenting process as is planned for offshore wind

The UK has the maritime and engineering expertise to harness its rich tidal resource. All that is required is the right policy environment to turn ambition into action.