New study reveals potential of tidal stream energy

SIMEC Atlantis Energy’s AR1500 turbine being installed at MeyGen, North Scotland (Credit SIMEC Atlantis Energy)
SIMEC Atlantis Energy’s AR1500 turbine being installed at MeyGen, North Scotland (Credit SIMEC Atlantis Energy)

Tidal stream power has the potential to deliver 11% of the UK’s current annual electricity and play a significant role in the government’s drive for net-zero, according to new research.

The School of Engineering’s Dr Athanasios Angeloudis is a co-author of the study which says that harnessing the power of the ocean’s tidal streams can provide a predictable and reliable means of helping to meet the country’s future energy demand.

Dr Angeloudis and the team reviewed marine environment modelling techniques, which are used to assess the power generating potential of tidal energy in the UK.

Role of renewables

The multi-university research, led by the University of Plymouth, was conducted in response to a call from the Department for Business, Energy and Industrial Strategy (BEIS) for evidence on the opportunities presented by the tidal stream energy resource.

The UK Government has already committed to a Net Zero greenhouse gas emissions target by 2050 and, in 2017, almost 30% of the UK’s energy was generated through renewable technologies such as wind and solar power.

However, electricity demand is expected to more than double by 2050 and while wind and solar will be the main contributors to meet this demand, a diverse generation technology mix is needed to keep the lights on.

Government funding barriers and recent developments

While the researchers highlighted the pivotal role that tidal streams could play in meeting energy demand, they also emphasise that government funding is key to accelerating innovation and driving down cost so that future projects can provide cheap electricity.

In the past, access to government funding has helped install 18 MW of tidal stream capacity, around 500 times less than the UK’s current offshore wind capacity. This relatively modest funding support to date has put the tidal stream sector on a steep cost reduction trajectory.

However, cost reduction has slowed since funding has been removed. Extending such support is essential to enable tidal energy to become cost competitive with gas turbines, biomass, and nuclear.

The study was last week cited by SNP Westminster Leader Ian Blackford, when he announced that £20million new funding will be ringfenced for tidal stream energy as part of UK Government efforts to support the burgeoning industry. This government funding commitment was one of the study’s desired outcomes at the time of its publication.

However, Blackford urged the government to release significant further funding, saying, “The level of investment that we put in now will ultimately determine whether the industry will reach its potential on these shores or we miss the chance and let it slip through our grasp.”

“Time is of the essence”

The study – published in Royal Society Proceedings A and led by the University of Plymouth – was released just a day before world leaders met at the COP26 conference in Glasgow to discuss the need for global agreements on clean energy.

Dr Danny Coles, Research Fellow at the University of Plymouth and the study’s lead author, said: “Our study shows there is considerable evidence to support an estimate that the UK and British Channel Islands’ tidal stream energy resource can provide 11% of our current annual electricity demand.

“Achieving this would require around 11.5 GW of tidal stream turbine capacity to be installed, and we currently stand at just 18 MW. It took the UK offshore wind industry approximately 20 years to reach 11.5 GW of installed capacity. If tidal stream power is going to contribute to the net zero transition, time is of the essence.”

Further findings

The study also explored the potential environmental effects of boosting tidal stream energy production, and found no evidence to suggest that the next phase of tidal stream development will cause significant detrimental environmental impact.

The physical environmental impacts are expected to be an order of magnitude less than those created by climate change. The regions with the highest tidal stream resource are the Pentland Firth and Orkney Waters, Scotland, and the Channel Islands – but both would require major grid infrastructure to connect them to high demand centres.

In tandem with that, however, other sites could be more easily developed on the South Coast of England and in the Bristol Channel, as they are in closer proximity to existing grid infrastructure and demand centres.

The UK government recently identified the grid integration of variable generation as a key challenge as renewable power penetration increases. Importantly, this new research finds that the cyclic, predictable nature of the tides can provide grid benefits over alternative variable power technologies such as wind, including supply-demand matching, for example.

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