dark blue sea water with white foam on the swell of the wave

dark blue sea water with white foam on the swell of the wave

Harnessing Wales’ marine renewable energy: the story so far

Published 22/05/2023   |   Reading Time minutes

With the second highest tidal range in the world, and an Atlantic-facing coastline providing a high energy wind and wave climate, Wales is well-positioned to make the most of the marine environment for renewable energy generation.

The Welsh Government has committed to decarbonise the energy sector, accelerate renewable energy development, and achieve net zero by 2050. It’s set a target to meet 70% of Wales’ electricity demand from Welsh renewable electricity sources by 2030. It also committed to support innovation in new renewable energy.

To mark the beginning of the ‘Conference of the Peripheral Maritime Regions’ (CPMR), which the Senedd is hosting, this article looks at what Welsh Government commitments mean for marine renewable technologies in Welsh seas.

Tidal energy: twice a day, every day

Tidal energy takes two forms; tidal range and tidal stream. Tidal range technologies harness the potential energy created by the difference between low and high tides. They generally involve construction of large-scale lagoons or barrages that retain and then release the incoming tide, like the previously proposed ‘pathfinder’ tidal lagoon in Swansea Bay. Currently planned projects include Blue Eden in Swansea, North Wales Tidal Energy, and the Port of Mostyn.

Tidal stream technologies harness the kinetic energy of currents to power turbines. Current projects include the Minesto project in the Holyhead Deep, the first low-velocity tidal energy project in the world.

By 2024, the Welsh Government says it will develop a ‘Tidal Lagoon Challenge’:

…providing robust evidence on the viability of the technology and the potential for supporting a project in Welsh waters that can demonstrate environmental sustainability in line with WNMP [Welsh National Marine Plan] objectives and policies.

The First Minister recently announced his ambition “to make Wales a world centre for emerging tidal technology”, alongside £750,000 of funding to support at least three tidal lagoon research projects. The Welsh Government says the research will address barriers that prevented development of the technology, as well as providing insight into the potential benefits.

Offshore wind energy

offshore wind farm, North WalesOffshore wind is an established and proven renewable energy technology. There are three operational offshore wind farms off the North Wales coast: Gwynt y Mor, Rhyl Flats and North Hoyle. However these ‘fixed-bottom’ offshore wind farms are limited to water depths of 60m.

As such, focus has turned to developing floating offshore wind (FLOW) technologies, which combine the platform technology used in the oil and gas industry, and wind turbines. This means wind turbines can move into deeper waters with higher wind speeds, and have less visual impact.

FLOW turbines are designed to be taller than traditional fixed technologies, allowing them to take advantage of the strongest winds at higher altitudes. The largest turbine in production is 265m, twice the height of the London Eye!

Marine Energy Wales, representing the marine energy industry in Wales, says “offshore wind will become the backbone of our future energy system”, which will require “100GW of installed capacity by 2050”.

FLOW in the Celtic Sea

The Celtic Sea, the area between south Wales, Ireland and Cornwall, is incredibly windy, but too deep for traditional fixed-bottom turbines. Marine Energy Wales is facilitating the development of FLOW in the Celtic Sea, saying it can deliver 24GW of energy and thousands of jobs.

The UK Government wants to develop 5GW of FLOW by 2030 as part of the British Energy Security Strategy. Marine Energy Wales highlight that FLOW development should be “rapid” to meet net zero ambitions, whilst minimising environmental impact and maximising local benefit. As such the Crown Estate (more on this below) has offered leasing opportunities in the Celtic Sea for FLOW projects, which may be developed in a phased or “stepping stone” approach. It says this approach recognises the need to develop the UK supply chain and supporting infrastructure, and provides opportunities for growth and investment.

The Crown Estate has been identifying broad ‘Areas of Search’ for potential FLOW opportunity, and distilling down to refined ‘Areas of Search’ as data becomes available. It’s also invested in marine surveys, and made data available to successful bidders to accelerate delivery of projects.

Marine Energy Wales sets out the stages of the ‘stepping stone’ approach in the Celtic Sea:

  1. Three separate 100MW scale test and demonstration projects delivered by Blue Gem Wind, Floventis and Flotation Energy. These will be deployed at demonstration zones closer to shore;
  2. Four separate 1GW scale developments planned by 2035. Beginning 30km from shore within five broad areas, which will require 250 floating turbines and power four million homes; and
  3. 24GW of clean energy delivered by 2035.

Minimising environmental impact

Environmental groups have long expressed concerns that inappropriately located wind turbines could have an impact on birds through collision, disturbance or habitat damage. The RSPB recognises the risk to nature from the climate emergency, including the prevalence of renewable energy installations, and says:

We must ensure our energy transition is developed hand in hand with measures to save nature.

Offshore windfarms can have a wider effect on nature, including on marine mammals, benthic ecology, fish, as well as visual impacts. Natural Resources Wales (NRW) and RSPB both say these impacts can be avoided/minimised through careful planning and siting of developments.

RSPB suggests that FLOW holds environmental advantages over bottom-fixed wind farms. It says FLOW can exploit areas away from breeding seabird colonies (which are generally closer to shore) and shallow foraging areas. RSPB suggests lower infrastructure impacts on the seabed could also reduce effects on marine wildlife.

Maximising the benefits for Wales

The Crown Estate is set to benefit financially from Wales hosting marine renewables, as it awards the right to use the seabed through a leasing process. Our article who owns the seabed, and why it matters, examines the Crown Estate’s role in developing Welsh marine renewables further.

The Crown Estate’s profits go to the Treasury, but also get used as a benchmark for the level of public funding for the Royal Family, known as the Sovereign Grant – which currently this sits at 25% of Crown Estate profits (a 10% increase on the usual 15% to fund the refurbishment of Buckingham Palace). Earlier this year it was reported that profits had increased by £1bn per year for at least three years, due to lease agreements for offshore wind (UK-wide).

As a result of previous (non-FLOW) offshore wind leasing, the Crown Estate reports that the value of its marine [renewables] portfolio in Wales increased from £49.2 million from 1 April 2020, to £549.1 million as at 31 March 2021. The Crown Estate hasn’t reported these values in its most recent report.

The co-operation agreement sets out support for “devolution of further powers and resources Wales needs to respond most effectively to reach net zero, specifically the management of the Crown Estate and its assets in Wales”. However, the First Minister highlights any decision to devolve the Crown Estate is for the UK Government, “and the appetite for any further devolution there is pretty limited, you can be sure”.

Increasing renewable energy generation is ever more important if Wales is to meet its net zero ambitions, and it’s clear that marine renewables can play a vital role in our future energy system.


Article by Lorna Scurlock, Senedd Research, Welsh Parliament