MeyGen

MeyGen (full name MeyGen tidal energy project) is a tidal stream energy plant in the north of Scotland. The project is located in the Pentland Firth, specifically the Inner Sound between the Island of Stroma and the Scottish mainland.

It is currently being constructed in a phased manner. The first phase of the project uses four 1.5MW turbines with 18 m rotor diameter which were installed submerged on the seabed in winter 2016/17.

The project is owned and run by SIMEC Atlantis Energy, although previously by Tidal Power Scotland Limited and Scottish Enterprise. Meygen was claimed to be the "world’s largest tidal stream power project". There are plans for up to 400MW to be installed at the site.

The high speed of currents in the area, reaching up to 5 m/s, made the chosen site in the Pentland Firth well suited to this type of energy generation.

History
In October 2010, the newly named "MeyGen" tidal project from the nearby Castle of Mey and "Gen" for generation was created by a consortium of Atlantis Resources Limited, Morgan Stanley and received operational lease from the Crown Estate to a 400MW project for 25years. In 2011 Norwegian partners Statkraft pulled out of the project.

A consent was granted in 2013, under Section 36 of the Electricity Act, to construct up to 61 two or three-bladed turbines with a total installed capacity of 86 MW. This was subject to construction in a phased manner so that potential environmental impacts could be understood. Each turbine was limited to 16-20 m in rotor diameter, rated at 1.0-2.4 MW, and connected to the grid by 6.6 kV cable.

Marine Scotland granted the project a license in January 2014. This initially only lasted until the end of 2020, but was extended in July 2016 to cover the period until 1 January 2041 or 25 years after completion of phase 1a.

Construction work on the project started in January 2015, building an access road towards the sea where the onshore power conversion building would be located.

In December 2016 it was announced that the first turbine had begun full power operations, and all four turbines were installed by February 2017. Phase 1 (formerly called Phase 1a) began operations in April 2018.

Some elements of the project were constructed outwith the licensed area, however after statutory consultation Marine Scotland varied the license in September 2017 to extend the consented site area. It was considered there were no additional impacts and that asking for full removal may have had adverse impacts.

Phase 1b was initially planned to add a further 4 MW comprising two AR2000 turbines, with another 73.5 MW in Phase 1c. Phase 1b was then revised to installing four turbines, bringing the total to eight. This required the Section 36 consent to be varied, to allow the additional two turbines above the six permitted in Phase 1. However, this phase did not proceed.

In July 2022, MeyGEN plc was awarded a contract to supply 28 MW of electricity to the GB grid in the Contracts for difference (CfD) Allocation Round 4 (AR4), which will be used to support the construction of Phase 2 which is now due to be commissioned in 2027

Four further contracts totaling 21.94 MW were awarded in the CfD AR5 auction in September 2023. An application was then submitted to vary the license conditions, to permit a smaller number of larger turbines to be used. These would be up to 24 m in diameter, remove the limit on the rated power per turbine, and increase the maximum voltage of the underwater cables to 33 kV.

, the plan is to install the next 28 MW of turbines as Phase 2 to be commissioned by 2027, and a further 22 MW as Phase 3 by 2028. Phase 2 is planned to consist of a further 10 turbines.

The site has the potential for a further 312 MW to be deployed beyond that, subject to expanding the consent. This would amount to 398 MW in total.

By 2018 the four turbines had produced 8 GWh. In 2019, they produced 13.8 GWh. Total cumulative production was 51 GWh by March 2023.

The project received £1.5million Scottish Government grant from the Saltire Tidal Energy Challenge Fund in 2020, to develop a sub-sea hub to connect multiple turbines.

Project description
Phase 1 of the project comprises four 1.5 MW turbines, three Andritz Hydro Hammerfest AH1000 MK1 and one Atlantis Resources AR1500 developed in conjunction with Lockheed Martin. These are all three-bladed horizontal-axis turbines with an 18 m rotor diameter, that reach the 1.5 MW rated power at a current speed of 3 m/s. They are mounted on three-legged gravity foundations that sit on the seabed, each weighing around 350 tonnes with six 200 tonne ballast blocks.

The turbines in phase 1 are connected to the onshore power conversion centre at Ness of Quoys by an individual cable per turbine. These are laid on the seabed, with landfall by 550 m long horizontal directional drilled conduits, installed in July 2015. The cables were installed by James Fisher Marine Services by November 2015, with a total length of 11 km. This used the DP vessel Siem Daya 1, and was completed over a 2½ day neap tide window. The onshore power conversion equipment was supplied by ABB.