Questions asked by the public

In France, GridLink carried out a preliminary consultation and then additional public consultations in accordance with the lessons learned.

The public consultations included six public meetings at important points in the project timetable, including at the start of the environmental studies, to provide a progress report on the environmental impact assessment and prior to the application for environmental authorisation:

07.12.2017 at Loon-Plage town hall

10.01.2018 at Bourbourg town hall

03.12.2019 at Loon-Plage town hall

10.12.2019 at Bourbourg town hall

07.10.2020 at Bourbourg town hall

14.10.2020 at Loon-Plage town hall

In the UK, GridLink carried out public consultations including an online public meeting on 11.09.2020 prior to the application for planning permission and a marine licence.  The public meeting was held online due to COVID-19 restrictions.

The questions that were asked at the public meetings are presented below.  Answers to these questions were given at the public meetings, and they are reproduced below.

 

PUBLIC CONSULTATIONS

  1. What steps have you taken to ensure that people are consulted effectively during the COVID-19 pandemic and lockdown in the UK?

Answer (BECG): Through our experience of delivering community engagement for projects like this, we have actually seen an increased response from previous projects [for participation in online public meetings compared to face-to-face public meetings]. This is perhaps due to people having more time and greater accessibility due to working from home and having enhanced digital engagement methods.

We are committed to engaging with the community about the plans for the GridLink Interconnector.

We have promoted ways to engage with us through the press, social media and delivered flyers to 4,800 addresses in the Hoo St. Werbergh Parish area. We provided two local information points in public spaces with high footfall, such as parks, which made information publicly available. We have also held briefing meetings with representatives from Medway Council and the Neighbourhood Steering Group.

We understand that these methods are unusual but given the unprecedented circumstances, we have sought to make our consultation as accessible as possible.

  1. Will your consultation process be ongoing throughout the length of the scheme in the UK?

Answer: We are holding consultation events like the public meeting voluntarily; whilst we are not required to as part of the planning process, we are committed to engaging with the local community and those likely to be impacted by the scheme. Our engagement will be ongoing throughout the development of this scheme.

  1. How do you engage with Medway Council in the UK?

Answer: We have been assigned a dedicated case officer within Medway Council and undertaken discussions with Medway Council officers for a number of years.

  1. Have there been efforts to engage with those in the French fishing industry that may be impacted by the scheme?

Answer: Yes, there have been efforts to ensure that anyone likely to be affected by the scheme has the possibility to engage with us. We have a dedicated fisheries liaison officer in the UK and we are making efforts to have similar engagements in France.

We will be holding similar consultation events in the UK and France, such as public meetings and virtual exhibition.

  1. Has your consultation feedback been affected by being virtual, rather than in person, in the UK?

Answer: The consultation process for the GridLink project includes virtual methods such as a virtual exhibition, public meetings and online feedback forms, and physical methods such as information points, arranging for copies of exhibition boards to be posted and offering physical feedback forms with freepost envelopes.

Offering both virtual and physical engagement methods help to ensure the local community and stakeholders can readily access information and engage with the consultation process for this scheme, despite the ongoing COVID-19 restrictions.

OPPORTUNITY / FEASIBILITY

  1. Will electricity flows between France and the UK go both ways? Why don’t the British produce the 1400 MW themselves?

Answer: Yes. France and the UK will be able to import or export electricity, which will strengthen the supply of these two countries.

The GridLink cable will be available to all European electricity producers, against payment (the customer who will rent, for example, the cables to transport 1,400 megawatts of electricity, with a hypothetical price fixed in the contract at 1 euro per megawatt, will pay a supplement for the cost of transport (with the amount regulated by the French and British authorities).

The interconnections concern the supply in Europe for the next 25 years. This does not meet only a British requirement. The idea is that each of the two countries can benefit from sharing at any time.

Regarding the 1,400 MW capacity, the decision is based on technology. We only want to use two cables to reduce the layout of the project whereas before we were working on 4 cables or more. Two cables allow us to transport 1,400 MW.

  1. Will this scheme only be used by the UK?

Answer: The interconnector can only transport energy – we cannot transmit our own power under EU law. Therefore, anyone can rent the capacity of the interconnector, whether that be from the UK to France, or France to the UK. Therefore, there are benefits for both countries.

This provides benefits, for example, if there is surplus energy from the UK, the interconnector can be used to provide energy to France and vice versa, thereby maximising the use of renewable energy.

  1. The surplus of electricity on the network allows to supply the English. If French policy decides to close Fessenheim and has trouble opening Flamanville, will we still have surplus on the electricity grid?

Answer: RTE provides on an application called éco2mix (https://www.rte-france.com/fr/eco2mix/eco2mix) all cross-border flows between each country. We see that France exports a lot of electricity, but there are times when it imports energy.  Many believe that it is only France that exports to the UK, but we want to have a vision for the future and plan for the next 25 years.

  1. Regarding the French and European electricity strategy, an energy node is being formed at the level of the Dunkirk agglomeration. Is GridLink part of a bigger project to create, for example, a future nuclear power plant to meet growing energy needs?

Answer: No. The connection installations proposed by RTE concern only the GridLink project.

  1. The power of the GridLink cable is 1,400 MW; IFA 2,000 is 2,000 MW. You go from 8 cables to 2 cables: does that mean that you increase the voltages and the cross-sections of the conductors?

Answer: Yes. The voltage of our cables is 500 kV, this allows us to carry more electricity in only two cables. If we kept 4 cables, we could effectively lower the voltage. The new cables allow this solution.

  1. Are the 500 kV cables new technology?

Answer: We use MI cables, rather than XLPE cables. Such cables have already been used on other projects. GridLink does not seek to use unproven technology. We wanted to find a technology that had already been used at least once or even more to be sure of its reliability. MI 500 kV cables already exist, so we chose this technology.

  1. Who will design the two cables?

Answer: The cables will be bundled within the same trench and put underground, but we have not yet chosen the provider who will supply the cables. We went through a process of preselection of suppliers, and now we are in the tender phase. The timing is no coincidence because we want to include the results of the ecological study in the criteria. Note that only 8 companies in the world can build this type of cable.

  1. Can Brexit call into question the realization of the project?

Answer: We are business people and not politicians. As far as we are concerned: nothing will be impacted by Brexit. The project remains timely, regardless of Brexit. There are already interconnections between the UK and the rest of the European Union. The need for an energy supply exists with or without Brexit.

BREXIT does not help the progress of the GridLink project, however the European Commission wishes to continue its collaboration with countries which are no longer part of the European Union, without forgetting that a project like GridLink will bring a benefit to both the France and UK.

From an engineering and commercial perspective, there are no major effects. Economically, there have already been assessments into the financial implications of Brexit on this project, such as the exchange rate for the pound to the euro or trading under World Trade Organisation (WTO) rules. There have also been assessments into the expected usage from France and the other European countries, to ensure that there is demand for the interconnector. The assessments conclude that the benefits of the project are not affected by Brexit.

There are many benefits from this scheme for both the UK and the EU economically and – through providing renewable energy – environmentally.

  1. Is the funding for the GridLink project completely private? Or is the state participating?

Answer: This is a fully privately funded project. But the private nature of the funding does not mean that there will be no control by the French state.  The GridLink project will be regulated by the Commission de régulation de l’énergie (CRE) in France and Ofgem in the UK.

  1. Is the GridLink cable installed to carry electricity from the nuclear power plant or that produced by renewable energies?

Answer: The cable will be open to all producers wishing to use it, regardless of the origin of the electricity; this balances supply and demand. The GridLink project is about transporting electricity, not generating it.

  1. Why haven’t we made the connection in the south of England, to avoid all this detour and this length of submarine cable?

Answer: What matters is where we can connect to the national grid in the UK.  National Grid, the UK grid operator, has given us 3 potential connection sites on the Kent coast. There are no suitable points to connect to the national grid further south in England.  So quite simply, this is the most feasible connection entry point for us in the UK.

  1. Is the progress of the project different in France and in Great Britain?

Answer: The project is being carried out in parallel on the French side and the British side because the final deadline is the same. The design of the converter station is the same as on the French side; the only difference is that the station across the Channel is located on a former coal plant, close to a substation.

The same strategy of consultation and environmental study is applied on the other side; however in France, the consultation process is much more rigorous and this makes it possible to point out certain elements which may not have been taken into consideration or too late.

  1. For IFA 2000, 4 cables were damaged but the 4 others were able to take over, what happens if there is a problem on the 2 single cables?

Answer: It happened to IFA 2000 because of a boat anchor that was dragged. If these 4 cables were damaged, it is because of their burial depth. GridLink will bury its cables deep enough to prevent this problem from recurring.

This is important to us because we want to protect our infrastructure, and it is also important for the safety of fishing activities.

The IFA 2000 link has been in operation since 1986. It was the first time that the cables were damaged.

  1. What is your experience on delivering projects of this scale?

Answer: We have brought together a project team that has a lot of experience within this field and has a strong track record of delivering projects of this nature, from handling the consultation process, permitting procedures and environmental impact assessment, to managing the construction of the scheme.

Intertek is a marine consultant and has worked on many schemes similar to GridLink’s scheme. Like the rest of the team, the company went through a bidding process to be chosen to be part of project. Intertek always learn lessons from every project it works on and builds on their experience. For instance, they have worked before on projects affecting the Thames Estuary and North Sea and this stood them in good stead to engage effectively with the marine community for the GridLink project.

In France, we are working with Arcadis, which is a major French environmental consultant, as well as Happy Day for local advice.

ENVIRONMENTAL AND SOCIETAL IMPACTS

  1. Will the GridLink cable generate electromagnetic radiation when in use?

Answer: The principle of installing the cable assumes that there is no impact in terms of electromagnetic field outside the trench where the cable is placed.

In direct current cables, electromagnetic fields are contained inside the cables.

For magnetic fields, the GridLink cable configuration places the cables together so that current flows in both directions; the effect of the magnetic field is therefore cancelled.

So, by combining these factors and the fact that the cables are placed in a trench under the ground and under the sea, the impacts on human health are therefore non-existent. This is a reason for the choice of the burial depth of the cables: approximately 1.50 meters underground and approximately 2 meters below the seabed, depending on the nature of the soil.

It is specified that technical specifications apply for alternating current cables, which have a very low frequency (50 hertz).  For many years, scientific studies have been carried out on low frequency electromagnetic fields. No study has been able to establish a cause and effect relationship between electromagnetic fields emitted by high voltage power lines and health. The website https://www.clefdeschamps.info/ provides information on low frequency electromagnetic fields.

  1. Are the impacts of the cable in terms of electromagnetic field different for direct or alternating current?

Answer: No scientific study has, to date, demonstrated any harmful effects of electromagnetic fields from power lines on agricultural land for direct or alternating current.

  1. In comparison with the cables of the H2V project (250 kV), shouldn’t we bury more deeply the cables of 400 kV of the GridLink project? And how should groundwater tables be taken into account?

Answer: The technical design of the cable and its depth are based on a geotechnical study; approximately 1.5 m is considered an acceptable depth for the high voltage cables used in the GridLink project.

Water tables, soil conditions, and the crossing of other networks will also be taken into account in the organization of the works.

The difference between the quoted values ​​for burial of 250 kV cables from another project and the burial values ​​of 400 kV cables for the GridLink project can be explained by a benchmark problem. It can be either the distance from the bottom of the excavation where the cables are placed, or the distance to the top of the cables.

The part of the GridLink project which will be managed by RTE will go to plots currently operated by farmers; a minimum burial depth is therefore essential to recreate the drainage above.  The studies are therefore developed according to these particularities, groundwater or salt water (so as not to pollute the wateringues).

  1. Will there be an increase in soil temperature? To what extent?

Answer: Studies to analyze the impact on soils are ongoing. Depending on the results, we can design our cables. The design principle of these cables is that there should be no thermal impact on the soil. In the design of the cables, we also do not want an electromagnetic field impact.

Finally, we want to make sure that the cables are buried at a sufficient depth so as not to be damaged.

  1. How high will the converter station be?

Answer: The maximum height of the converter station is 25 m, but its average height will be between 10 and 15 m.

  1. What will be the configuration and footprint of the future Warande substation?

Answer: At this stage of the technical and environmental studies, the design of the building is not fixed, but its design will be made in conjunction with residents and the agricultural stakeholders to minimize the impacts on farming activities and the landscape.

  1. Are preventive archaeological excavations planned on the site of the converter station in Dunkerque?

Answer: The Zone de Grandes Industries (ZGI) has already been the subject of a referral to the DRAC by the GPMD in matters of preventive archaeology and relevant excavations have taken place. No further excavation is planned.

  1. Can the installation of the cable prevent a possible widening of the A16 motorway at Dunkerque?

Answer: No. The route of the cable has been discussed with the Port of Dunkirk and the national authorities, taking into account all the projects in progress or under study.

  1. What will be the impact on the environment and on the inhabitants located near the converter station at Dunkerque? Why were the inhabitants of Saint Georges sur l’Aa not invited when they are also affected?

Answer: The converter station should be seen as a large substation with all the valves and reactors located inside buildings to protect them from the elements. This is so-called passive equipment that generates no energy, therefore no noise pollution. There are transformers that can make a bit of noise and there is a cooling system with fans. But if you compare it to a nuclear power plant, it’s much less noise pollution.

  1. At the converter station, will electromagnetic radiation be generated? I ask the question for the population located nearby … And if a sound study is done, will there be noise?

Answer: Design studies are ongoing but the basic principle of this study is that there should be no impact of electromagnetic fields on the area. We are working on occupational safety issues within the perimeter of the station. We are doing the studies to ensure that but we are sure there will be no such problem. It is based on other examples of existing stations around the world that follow this system. Studies are also being carried out to limit the noise impact.

The closest house to the station in Dunkerque is located about 300 m away. Once we have all the results of the studies, we will make all the necessary corrections. We will take into consideration the recommendations to ensure that the construction of the station guarantees the safety of all.

  1. Is it possible to specify the exact route of the cable on the Port land?

Answer: The GridLink project is informed of the new projects and takes them into account. The route is linked to the legal easement granted by the Grand Port Maritime de Dunkerque, so even if the route sometimes approaches other cables, a safety distance is systematically maintained.

  1. Will there be more lightning strikes on the Warande substation and the future Bourbourg substation? What are the risks of repercussions for surrounding homes?

Answer: All the works are protected against the risk of lightning.

The combined surface area of ​​the two substations linked to the project is comparable to other RTE substations in France which are no longer subject to lightning strikes.

  1. Do you see there being any environmental effects from this project that are not covered by your environmental report?

Answer: As part of preparing the permit applications, we are required to assess any effects that the project may cause during construction and operation. Our assessments have concluded that there are no significant environmental effects and that any effects will be properly mitigated.

Our environmental studies assume the ‘worst case’ scenario, so we do not anticipate any further environmental effects arising from this scheme. In fact, any environmental impact may be smaller than mentioned in the report.

IMPACTS ON AGRICULTURE

  1. Will the cable burial works have an effect on farmers’ crops?

Answer: Everything will be done to keep the land arable; the work schedule will be established in conjunction with the agricultural stakeholders; soil studies have been carried out; the organization of the work areas will also be discussed with the farmers. Finally, the cable route has been designed to run along the edge of arable land as much as possible.

  1. Will the cable’s burial depth allow agricultural activities to resume on the surface?

Answer: The burial depth goes beyond the usual recommendations; moreover, if certain places were to be buried deeper, the recommendations would be followed in order to restore the drainage to the same level of functionality as it was before the work. The objective is to continue the exploitation of the plots as before by preserving the exploitation of the land. For some sites, agronomic monitoring of the plots crossed may be carried out by the Chamber of Agriculture.

  1. Who is in charge of verifying that the restoration of land is carried out by the companies?

Answer: One of the fundamental principles of the project is to ensure that agricultural activities resume normally after the placement of the cables. This issue concerns all stages of the work: excavation, cable installation and backfilling the trench. If the impact of the works on agriculture becomes too great at any point, then compensation could be considered.

In addition, RTE regularly creates underground lines in agricultural land and therefore often works with the Chamber of Agriculture, which conducts soil studies to check the different types of soil and specify how to excavate and separate the soil without mixing them together. Soil scientists from the Chamber of Agriculture are appointed to monitor the work of the companies. The Chamber of Agriculture then has a right of alert vis-à-vis RTE if the recommendations of the Chamber of Agriculture are not respected during the construction phase, and RTE sometimes stops the work.

  1. 9 hectares of agricultural land will disappear. The fear of farmers is: will ecological compensations consume other agricultural land?

Answer: We wish to limit the ecological compensation but it is premature for us to answer, because the analysis of our study results is underway. If ecological compensations are necessary, we can try to ensure that they do not concern agricultural land.

The objective of environmental studies is also to be able to redirect the route of the cable to avoid areas with ecological issues that may require compensation.

  1. Will the Wateringues issue be taken into account during the cable installation work?

Answer: Yes. Discussions are being held with the Wateringues sections and the environmental studies are used to determine how to manage the crossings of watergangs. In some cases, directional drilling will be used (thus passing under the watergang).

In general, GridLink and RTE’s desire is to minimize all the impacts of the project, in particular, by listening to all stakeholders. It should also be noted that the law requires the contracting authority to minimize its impacts as much as possible. In the event that it is not possible to avoid an impact, the contracting authority must reduce them or even compensate them. This is the subject of environmental studies and then authorizations.

  1. What will be the impacts on the landscape?

Answer: The cable is being buried; there is no impact on the landscape. The impacts are at the converter station and the extension of the Warande substation.

The converter station is located in the Zone de Grandes Industries (ZGI) planned for this type of facility. It will be the subject of landscaping. The extension to the Warande substation is to expand existing equipment. Discussions are and will be held with the farmers concerned to minimize or compensate for the impacts.

Regarding the converter station, only 2.5 hectares are sufficient for the activity, the rest of the 4 hectares can provide for landscaping.

The footprint of the Bourbourg substation was reduced from 7.5 to 6.5 ha.  The height is not known at this time.

CONNECTION TO THE NATIONAL NETWORK IN FRANCE

  1. How will the Warande substation be linked to the converter station?

Answer: The connection will be made by underground cables

  1. Why not build the converter station near the Warande substation?

Answer: It is appropriate that the converter station be built in the Zone de Grandes Industries (ZGI), insofar as this sector is very suitable for such an installation.

  1. Why extend the Bourbourg station when RTE has other sites?

Answer: It is technically not possible to build this infrastructure north of the Warande substation or in the technical corridor to Gravelines, and the southern part is more suitable for technical reasons.

The COVID-19 pandemic has not affected the overall GridLink project.  The economic and environmental benefits of the project to France and the UK remain the same regardless of the COVID-19 pandemic. 

Due to the negative effect of the COVID-19 pandemic on the economy, it may reduce some of the demand for electricity in the future.  However, this effect is short term.  Over a longer period of time, the demand for electricity and the need for interconnectors will be unaffected due to the goals for electrification, for example electric cars, and development of renewable energy to achieve climate change reduction.    

COVID-19 has delayed some of the studies and activities required for the preparation of the environmental impact assessments due to restrictions imposed by Government guidelines and our objective to ensure that everybody involved with the GridLink project is kept safe and healthy.  In particular, public consultations were postponed from June-July to September-October 2020 and the format was changed.  The public consultations in the UK have been carried out using an online platform, including a virtual exhibition on our web-site and an online public meeting.  In France, two public meetings were carried out in accordance with the Government guidelines for COVID-19 and a virtual exhibition was added to our web-site.

In the UK and France, we increased the advertisement of the public consultation events to contact the general public as much as possible.  This included delivery of flyers to resident’s addresses, newspaper and radio advertising, social media advertising and information points at popular locations.

Therefore, although the COVID-19 pandemic has caused some delays and difficulties for the GridLink project, the work has continued and the overall timetable is not significantly changed.

GridLink has taken the possible effects of Brexit into account.

The economic and environmental benefits of the project to France and the UK, and for the wider European Union (EU), remain the same regardless of the outcome of the Brexit negotiations.  The need for improved energy systems exist with or without Brexit, and do not change if the final arrangements represent a “soft” or “hard” Brexit.  The EU already has interconnectors to non-EU Members, such as Norway. 

From an engineering perspective, there are no effects caused by Brexit.  GridLink is undertaking the procurement of the construction contracts in accordance with all applicable EU directives and rules, so that a transparent and competitive process is applied.  This approach will not change due to Brexit.  

Economically, we have assessed the financial implications of Brexit, such as the exchange rate for the pound to the euro and energy trading under World Trade Organisation (WTO) rules. We have studied possible changes to supply and demand forecasts from France and other European countries.  The assessments conclude that the benefits of the project are not affected by Brexit and it remains one of the lowest cost interconnectors in Europe.

Given that there are many benefits from the project for the UK, France and the EU economically and – through providing renewable energy – environmentally, GridLink Interconnector Ltd is confident in the future after Brexit is completed and it is ready to invest approximately EUR 900 million to build the interconnector.

There are significant economic and environmental benefits to both the UK and France from building a new interconnector.  As well as providing the opportunity utilise surplus electricity generation and efficiently use all available renewable energy, it provides a means of ensuring security of supply on a short term basis when the need arises due to any problems with electricity production or the transmission system.

Important studies about the need for interconnectors are published by the European Network of Transmission System Operators (ENTSO-E) and the national transmission system operators, National Grid in the UK and Réseau de Transport d’Électricité (RTE) in France.

The ENTSO-E Ten Year Network Development Plan 2020 (TYNDP 2020) indicates a need for 5,4 GW of UK-France interconnection by 2030 and 6,8 GW by 2040.  The latest estimates of National Grid are higher, with an optimal interconnection of 5,8 to 8,8 GW by 2030.

GridLink has a unique location and design specification, together with a short cable length, which means that it is expected to be one of the lowest cost interconnectors in Europe (as EUR per MW).  This means that it is the best option to meet the demand for new interconnection between the UK and France.

The electricity flows through the GridLink interconnector may be in either direction at any time.  GridLink has evaluated the amount and direction of the electricity flow over 25 years of operation from 2025 to 2050.  Depending on future changes to the energy system, such as demand forecasts, sources of supply and climate change targets, the flow may vary in both directions.  In general, the majority of the flow (up to 80%) is expected to be from France to the UK at the start of commercial operations, but this proportion is expected to reduce over time and vary from day-to-day and week-to-week at different times of year.

When the interconnector is used to transport electricity from France to the UK, it provides the opportunity for French energy producers to increase revenue from surplus electricity sales that cannot be utilised in France. In this case, the UK consumer benefits from security of supply and a competitive source of electricity.  The reverse applies when the electricity flow is in the opposite direction.

GridLink is not permitted by European Union rules to produce power or trade power transported through the interconnector.  These rules are designed to prevent any company having a monopoly on both power generation and transportation.

GridLink will own and operate the interconnector and earn income by charging a fee to other companies to send power through the interconnector.  The income earned by GridLink will be regulated by Ofgem in the UK and Commission de Regulation de l’Energie (CRE) in France.

The use of the interconnector must be offered on a non-discriminatory basis.  Power may be transported in either direction from France to UK or vice versa at any time. 

The amount of power that is transported will depend on the supply and demand for electricity.  In particular, it is expected that the interconnector will be used for the transport of excess renewable energy, such as wind or solar, or nuclear power, which becomes available when the supply exceeds the local demand or existing grid capacity.  Therefore, the interconnector will facilitate the use of low carbon sources of energy that would otherwise be unused and lost.

During the transport of electricity over long distances, a power cable loses energy due to the heating of the conductor caused by the electrical current. Additional energy is lost due to the energy demand, heating, noise and other phenomena related to the operation of ancillary equipment needed to connect the power cable to a local distribution system or consumers at each end.

The laws of electricity mean that operating the power cable at high voltage reduces the electrical current.  This, in turn, reduces the energy losses.

The amount of energy loss is influenced by the cable design and length.  Energy losses are reduced if the cable length is shorter.

Transmitting electricity as direct current has lower energy losses than alternative current because the current is uniformly distributed across the conductor.  In alternating current, the current is concentrated at the conductor surface which increases the energy losses.

Whilst direct current technology always has lower energy losses, it is more expensive to install.  Therefore, alternating current is preferred for economic reasons for transport of electricity over short distances, up to the point where the lower costs of the equipment is outweighed by the higher operational energy losses.

For GridLink, it is estimated that the total energy losses will be in the range 2% to 2.5%.  For an equivalent system operating with alternating current, the losses are expected to be 6% to 7%.

Therefore, GridLink has chosen to utilise a high voltage, direct current cable to obtain the lowest energy losses.  The relatively short cable length will also minimise the energy losses related to the interconnection.

Electromagnetic fields are generated by a power cable due to the electric current flowing through the conductor. The current produces both an electric field and a magnetic field, which are collectively referred to as electromagnetic fields (EMF).

The design of the cable, including metallic screening, lead sheathing and/or armouring, contains the electric field within the cable and prevents any propagation into the environment.  Therefore, there are no electric fields around the cable.

However, a power cable does produce a magnetic field that emanates into the surrounding environment. 

For subsea cables, a phenomenom is possible that an electric field is induced by the movement of water currents or other objects through the magnetic field.  The burial depth of the cable under the seabed prevents any measurable induced electric field caused by this phenomenon.

The magnetic field of the cable should be considered in the context of the background geomagnetic field of the Earth, which ranges from 25 to 65 μT.  At the location of the GridLink interconnector, the Earth’s geomagnetic field is approximately 50 μT.  People are often exposed to higher magnetic fields on a regular basis from portable electrical gadgets and equipment, including hair dryers, vacuum cleaners and microwave ovens.  Magnetic Resonance Imaging (MRI) used for medical diagnosis exposes patients to more than 100,000 times the background geomagnetic field.  The International Commission on Non-Ionizing Radiation Protection (ICNIRP) most stringent guideline value for limiting public exposure to magnetic fields is 500 μT, with the level to protect public health set at 40,000 μT.

The magnitude and range of a magnetic field from a power cable depends on the configuration of the cable, strength of the electric current and the density of the surrounding material.  The GridLink interconnector consists of two high voltage, direct current power cables that are bundled together. In this configuration, the electric current in each cable is flowing in opposing directions to complete the circuit.  As a result, the magnetic field produced by one power cable is equal and opposite to the other cable and they tend to almost cancel each other out.  The residual magnetic field is very small. 

With a burial depth of 1.5m on land and 2m under the seabed, it is expected that the increased magnetic field above the cable may range from no change up to 20% above the typical background of approximately 50 μT.  Any magnetic field will not be detectable within 5m to 10m from the cable. Any increase is also well below the ICNIRP guideline values and within the natural variation of the Earth’s geomagnetic field, so it has no negative effects.

The depth of burial of the cable will be determined by the type of soil, existing underground public utilities and environmental features that must be crossed.

The indicative depth of the cable is 1.5 m.  This is a typical burial depth for electricity cables.  The cable will be protected from accidental disturbance by a protective concrete layer above the cable and a warning marker buried in the soil.  It will not be possible for anything to accidentally penetrate the cable from above due to this protection.

Where the cable crosses railways, road embankments and water drainage canals, horizontal directional drilling will be used to enable the cable to pass underneath the existing infrastructure.  Such horizontal directional drilling may be 5-10 m below ground level.

The burial of the cable is shown in the illustration below:

The cable will be buried at sufficient depth to ensure that farming can continue after the cable has been installed.  The only restriction on the land will be the prohibition of new farm buildings within 5m.  All other surface land uses, including access roads, ploughing and harvesting will be unaffected.

The cable installation will require the excavation of a trench.  The topsoil will be removed and kept separate from other excavated materials.  After cable installation, the trench will be backfilled and restored with the return of the topsoil layer.

The restoration of the trench and any temporary construction areas will be carried out in a way to avoid changes to the compaction of the soil or drainage of the land.

The Environmental Impact Assessment has included a pedology study carried out by the Chamber of Agriculture.  This study will be used to inform the environmental and technical studies to ensure that the agricultural soils are properly protected during construction works and restored afterwards.

The converter station and cable installation will generate traffic during construction.  The construction traffic will comprise the typical vehicles used for all construction projects, including workers cars and mini-buses, light good vehicles and trucks.  A small number of special loads due to size or weight, such as delivery of transformers, will be required.

During operation, the converter station has a small number of employees and does not require routine delivery of any materials or consumables.  Therefore, there will be very small traffic generation during day-to-day operations.

The converter station will comprise a range of industrial buildings containing electrical equipment, together with some outside electrical equipment installed within fenced compounds.  The converter station will require 3-4 ha of land, with less than 2 ha being developed as buildings.

According to preliminary designs, the main buildings are a valve hall up to 25 m high, reactor hall up to 20 m high and other service, control and storage buildings up to 10 m high.  In addition, transformers, harmonic filters and switchyard equipment may be up to 15 m in height.

The buildings will be designed to resemble typical logistics and distribution warehouses or similar industrial buildings.  The colour scheme and building materials can be chosen to assimilate with other buildings in the area or landscape designs.

In addition to the benefits to electricity producers and consumers through improved network integration, security of supply and reduction in wholesale electricity prices, there will be local economic benefits.

The construction of the GridLink project will employ local companies and workers.  Although the main electrical equipment and cables for the converter stations are manufactured in specialist factories, local companies will be needed to supply construction materials and equipment, construction services, transport and logistics, temporary accommodation, catering, office and similar services.  The construction works will require a range of skilled construction workers and manual labourers, with a team of up to 200 workers at each converter site.  It is expected that local construction workers will be employed to carry out many tasks, including site surveys, site preparation, excavation and civil works, foundations, building erection, supply and installation of public utilities, supply and installation of general equipment, and landscape restoration.

For the offshore cable-lay activities, port facilities, berthing, victualing, refuelling and associated services will be required for the specialist cable-lay vessels and any support ships.  These are likely to be provided by the Port of Dunkerque and/or Port of Sheerness, or other nearby ports.

During operation, there will be up to 8 full-time equivalent personnel located at each converter station.  The personnel will supervise the operation of the converter station as well as service contracts for equipment maintenance, security, property maintenance and landscape gardening.  In addition, 12 personnel will be employed in the control room and as technical managers.  These personnel may be located at the converter station site or at another location, depending on the organisation of the commercial offices. 

The operations personnel will be supplemented by maintenance engineers and support workers responsible for routine maintenance and repair, including regular major maintenance activities each year or every two years.

The commercial management of the business will also employ 15-20 persons at the company headquarters.

GridLink Interconnector Ltd will pay national corporate taxes and local business taxes, such as the Cotisation Foncière des Entreprises (CFE) in France and business rates in the UK.  These taxes are based on company revenues and/or property valuations, so they will depend on the company’s financial performance and land valuations set by the local authorities.  They are expected to make a significant contribution to local tax income.  In the UK, business rates at the current rate are approximately £1m per year, and the CFE in France is approximately EUR 200,000 per year.

GridLink Interconnector Ltd also pays rent to lease the land for the converter stations and easements for the underground cables.  The payment rates are determined by the agreements with Grand Port Maritime de Dunkerque in France and Uniper in the UK, and provide revenue for these companies to support their operations.

For the connection to the national grid by RTE in France, the new Bourbourg substation will be subject to the Cotisation Foncière des Entreprises (CFE) and the Taxe Foncière (TF) as well. The annual payment of the CFE is estimated at approximately EUR 50,000 (of which 85% for the community of municipalities) and the payment of the TF is also estimated at approximately EUR 50,000 (distributed approximately 55% for the municipality, 35% for the department and 5% for the community of communes). In addition, EUR 5,000 will be paid each year to the municipality for the additional 400 kV pylon under the pylon tax.

Therefore, the provision of construction services, employment of construction and operations workers and payment of corporate taxes are expected to make a notable, positive contribution to the local economy.