The governments of Scotland, Northern Ireland and Ireland commissioned a feasibility studying into creating an offshore interconnected electricity grid based on wind, wave and tidal generation (ISLES Project), which was part funded by the European Union Regional Development Fund.
The study was commissioned against the background of EU policy to provide competitive, sustainable and secure energy with a strategy aimed to increase the percentage of renewables in the EU energy mix to assist in the decarbonisation of the system. The results of the study has now been released.
It is also an objective that the internal market in energy be further developed to allow cross border energy flows through better interconnection, underpinning security of supply and transporting energy in a cost effective manner to increase consumer benefits across Europe.
Northern and Southern ISLES
The study focused on an initial 'ISLES Zone' stretching from the west coast of the Isle of Lewis down to the north coast of Northern Ireland and the North Channel; and further south into the Irish Sea along the east and west coast of Ireland. The maximum resource potential in this area is estimated to be in the order of 16.4GW.
In shaping the ISLES Project, a balance has been struck between ambition on one hand and on delivering early viability of the concept on the other. As a result, two ISLES concepts were developed to match technological resources currently available with the available onshore transmission network capacity and to explore the integration of multiple marine resources into a single offshore network.
It appears that a 'Northern ISLES' concept, comprising 2.8GW of offshore renewable generation and interconnection capacity, could be created on the south west coast of Scotland with additional resources on the north coast of Northern Ireland and the Republic of Ireland. It is suggested that this zone would be primarily connected at a single connection point at Hunterstown in Scotland with a maximum export capacity of 2.5GW and onshore connections at Coolkeeragh and Coleraine in Northern Ireland.
The 'Southern ISLES' concept considers a network and offshore generation along the east coast of Ireland. Shared capacity of 3.4GW of generation would be connected to the GB mainland and up to 2GW of interconnection would be created between the GB and Irish markets. In contrast to Northern ISLES, this concept comprises predominantly near-shore generation developments. The Irish onshore transmission network has limited coastal network capacity and as such, simple point-to-point links will be of significant length before reaching a suitable onshore connection point.
The Southern ISLES concept does not currently envisage development of the west coast of Ireland as the transmission network onshore in the west is not sufficiently developed to accept the levels of generated capacity which would be created.
Key considerations for development
In order to progress the ISLES concept in general, a number of key elements must be considered. Essentially, transmission grids in each of the jurisdictions must be upgraded to accommodate the increased levels of intermittent generation which would come on stream in order to prevent onshore grid constraints.
It would appear that the proposed dominant connection point for the export of the power generated would be the GB onshore system, which it is thought is sufficiently developed to accept this additional capacity. The secondary load centre would be the Irish onshore system, however, there already exists a high level of renewable generation on the island system and further capacity may not be easily accommodated.
Environmental factors have been reviewed in the feasibility study. Subsea cable corridors for both the Northern and Southern ISLES concepts were developed with no adverse environmental constraints identified. However, landfall points along the coastal areas of all three jurisdictions have significant restraints due to flora and fauna protected areas and amenity values attached to the coastline.
The scale and nature of the operation to construct these concepts was found to be feasible. However, the availability of cable lay and trenching vessels may lead to tight constraints around 2020 in the timeframe of the UK Round 3 offshore wind farm construction.
Cross-jurisdictional complexity
The feasibility study has shown that the ISLES Project would provide both opportunities and challenges in developing a cross-jurisdictional offshore transmission network that connects large-scale offshore marine generation, provide enhanced interconnection and facilitate additional onshore grid and electricity market benefits.
The cross-jurisdictional nature of the concept raises complex questions across multiple regulatory authorities in three different jurisdictions. A key pathway to the development of an offshore interconnected transmission network is having a fit for purpose planning and consents regime in place. This poses particular challenges in terms of navigating the complex and evolving onshore and offshore planning and licensing regimes, in addition to changing legislative and policy frameworks in each of the three jurisdictions.
A primary task will be to determine the necessary planning procedures and licences which will be required and review these to determine how these requirements fit with the current marine and onshore legislative regimes within Scotland, Northern Ireland and Ireland.
A danger for the ISLES Project would be piecemeal development in order to satisfy the different marine and onshore consent and associated environmental assessment requirements in each of the jurisdictions, where some elements of the project would secure approval whilst others may not.
Notwithstanding emerging and proposed legislative reform in each jurisdiction, there is no overarching streamlined consents mechanism which can currently be utilised for projects, such as this one. Ideally, each jurisdiction should have a single consents regime for onshore and marine projects whilst taking into account the future possibility of cross-jurisdictional interaction on consent. It is possible that such provisions may be created as a standalone regime tied to the specific nature of the project, which is essentially an energy infrastructure project of strategic national importance in each of the three jurisdictions.
What happens next?
Although in itself ambitious, 2020 is considered to be the earliest timeframe in which the ISLES Project could be implemented in terms of resolving regulatory and legislative issues, having the required supply chain capacity in place and providing an attractive energy landscape to support its commercial viability.
The British-Irish Council is ceded with the task of progressing these concepts and, together with the governments within the three jurisdictions and Europe, bringing the project into reality. It is hoped that the ISLES Project will be an exemplar EU energy project which will deliver economic benefits and increased security of supply for all stakeholders involved.
This article contains a general summary of developments and is not a complete or definitive statement of the law. Specific legal advice should be obtained where appropriate.
