FAQs

FREQUENTLY ASKED QUESTIONS

1.  What is so special about tidal energy?

Wind energy and wave energy are driven by the heating and cooling of the planet as it rotates about its axis. Ultimately wind and wave energy are simply a converted form of solar energy from the sun’s rays falling on us and are dictated by the sun and planets’ weather systems. There is huge energy potential to be extracted from these natural resources but, as it is frequently discussed, one of the key problems is predicting the availability of this resource at any given time. It is relatively easy based on use of measurements and historical data to say for any given year how much energy a wind farm or a wave farm may produce. What is not easy is to predict how much energy it will be producing at any given moment.

By contrast, tidal energy is not converted solar energy it is driven by the rotation of the planet and the gravitational forces resulting from the proximity of the moon and, to a lesser extent, because of its enormous distance from us to the sun. As navigators have known for many years this means that the tides can be predicted with great accuracy and not just a day ahead, but years, or even tens or hundreds of years in the future. For a tidal farm then, once the relationship is determined between the speed of the tidal flow across a site and the energy that the devices installed can extract from the flow, yield predictions can be predicted many years ahead.

2.  What is the relationship between Alderney Renewable Energy and the States of Alderney?

Alderney Renewable Energy Limited (ARE) is a renewable energy development company with an exclusive 65 year licence to develop tidal projects in Alderney’s waters.

This licence, under Part ii, Section 9 of The Renewable Energy (Alderney) Ordinance 2008, was issued to ARE in 2008 by the States of Alderney (SoA) and the Alderney Commission for Renewable Energy (ACRE).  ACRE was established under the Alderney Renewable Energy Law 2007 to regulate this licence.

This licence provides, subject to individual operating consents, access to an area of 48 square miles of Alderney's territorial waters and permits ARE to install tidal turbines and infrastructure for tidal energy systems.

3.  What has the Island gained by issuing a licence to ARE?

The terms of the licence require ARE to pay an annual option fee of £345,000 for the 48 square miles of seabed that forms its licence area. In addition, ARE pays a further £200,000 per annum to ACRE. This fee provides a direct reduction to energy costs to the Island’s residents. Since 2008 ARE has paid fees in excess of £3.5 million.

When the tidal projects begin to generate power a generation fee will also become payable for every unit of power generated. This fee will be aligned to similar tidal projects in both UK and French territorial waters.

It has been estimated that the first commercial scale project planned for Alderney will provide generation fees in excess of the £545,000 fees already paid annually by ARE. Once generation fees exceed the annual fee in any one year, the requirement for the annual fee payable by ARE falls away.

4.  Why is Alderney’s territorial waters considered to be a good for tidal energy projects?

There are many elements to this question, but in relation to the available resource, the tides off Alderney are strong over a large area and are bidirectional, i.e. the ebb and flood tides are almost 180 degrees opposed. This is not always the case and a number of tidal sites have flows of 30 degrees between opposing tides. This can cause problems with yield because the technology needs to deal with quite different approach flows.

The infamous Alderney Race and resultant tidal flows could provide an estimated 3GW of predictable renewable energy. The territorial waters of Alderney contain one of the world’s largest single tidal energy resources which, once fully developed, is estimated to provide enough power for 1.8 million homes.

5.  How do ARE intend to develop and deliver the first tidal project?

ARE, with its partners, will develop tidal projects to secure the necessary operating consents. These consents will be granted and regulated by ACRE and the consented projects will then be subcontracted to energy companies. These energy companies will own, construct, operate and maintain the tidal projects. Each project will provide 25 years of revenue generation after which, the project could be either decommissioned or subcontracted for a further 25 years.

ARE and OpenHydro (OH) have signed a joint venture agreement which will see the two companies combine their expertise and resources to develop the first 300MW tidal project in Alderney’s water. The joint venture company is called Race Tidal Limited (RTL).

This project will see the deployment of between 150 - 200 16 meter diameter OH turbines and subsea bases at a depth of 40 metres.

Grid connection for this project will be via the FAB Link interconnector, which will be a regulated trading link between France and Britain, routed via Alderney. The link via Alderney will provide the connection point for the 300MW tidal project and for the Island of Alderney to enable power to be imported to the existing electricity grid.

Turbines and subsea bases for the RTL 300MW project will be manufactured and supported from a DCNS turbine facility in Cherbourg. This facility will have sufficient industrial capacity to service turbine production and maintenance requirements for Alderney’s projects. DCNS is the majority shareholder of OH.

RTL will now carry out project development activities including engagement with stakeholders, tidal resource evaluation, seabed characterisation and an Environmental Impact Assessment. The results of these studies will feed into the operating consent application that the company intends to submit early 2018.

RTL will also benefit from the demonstration projects planned within the French side of the Alderney Race (Raz Blanchard) in terms of environmental and performance feedback. This feedback will provide beneficial performance and environmental characteristic to assist the RTL 300MW project consenting process.

This business model of “survey – develop – consent – subcontract” is repeatable and will be adopted by ARE to develop further projects. The extent of future development will be limited by the export capacity of FAB Link.

6.  What has Alderney Renewable Energy been doing since 2008?

ARE, under its licence, are permitted to measure the tidal resource around Alderney and deploy test turbines to prove both the resource and tidal technology. ARE has completed a number of resource assessment campaigns, which have seen the deployment of several static devices placed on the seabed to measure the tidal flows through the water column. The results of these assessments have been used to model, predict and estimate the yield that could be generated once turbines are deployed.

One project that has been reviewed by ARE was a 2 turbine installation linked to a hydro-electric system at Fort Albert. Following a detailed feasibility study it was decided not to pursue this project on economic grounds.

Subsequent to this decision, emergent projects have been developed outside of Alderney’s territorial waters, which will provide reference information of great significance than that which would have been delivered from the Fort Albert project.

ARE has continued to develop its partnerships with OH. OH are majority owned by DCNS, the French naval defence company.

ARE has also commenced development of the first commercial scale tidal project with OH in Alderney’s waters in the Race and have developed advanced plans for the FAB Link interconnector cable.

7.  Alderney’s power demand is small, so what will happen to the excess tidal power?

Alderney’s peak consumption is around 1.5MW of power. The current approach is to develop tidal projects up to the capacity of the FAB Link interconnector cable, which is currently specified between 1 to 1.4GW. So, the eventual power generated from Alderney’s water could be some thousand times great than that which is actually consumed on Alderney.

The FAB Link interconnector cable will run via Alderney with connections to both the south coast of the Britain and to the Normandy coast. Tidal power will be exported via this link, which will also provide a link to enable the Island of Alderney to import power into the existing electrical grid.

8.  What are the plans over the next 3 – 5 years for the Alderney tidal projects?

The current plan is to develop and gain operating consent for one of the world’s first commercial scale tidal projects at 300MW in the Race – anticipating construction in 2021/2023. Concurrently to this the FAB Link Project will be developed and consented to provide between 1 to 1.4GW of tidal export capability – anticipating construction start in 2018, with a 3 - 5 year build programme.

9.  Why is FAB Link important and who are the developers?

Tidal flows in the Alderney Race can exceed 4 meters per second and with tidal generating capacity matching that of the interconnector, it is estimated that tidal energy flows, via the link, will occur for around 30% of the time. In the absence of tidal generation, when the tidal velocity falls below the minimum levels to generate tidal power, conventional energy will be traded via the interconnector, between the UK and French markets. FAB Link, once the first tidal project has been constructed, will enable the Island of Alderney to import power onto it’s existing electrical grid.

By removing the requirement, via FAB Link, tidal projects in Alderney no longer need to develop and construct  dedicated tidal export cables, thereby improving their commercial viability. This requirement is a major stumbling block for equivalent tidal projects in Scotland and Canada.

FAB Link Limited is a joint venture between ARE and Transmission Investment LLP. FAB Link Limited has already entered into arrangements with the French grid operator, Réseau de Transport d’Electricité (RTE), to be responsible for the development of the project’s assets in France and French territorial waters. An agreement with National Grid for connection to the existing British onshore grid has also been agreed.

10.  Why can’t we be more specific about the location and site layout of the RTL 300MW project?

The RTL 300MW project is planned to be located in the Race, in the proximity of the race rocks. The exact location and layout will be confirmed following site surveys and assessments.

The detailed site layout depends on a number of factors. Before the precise layout is determined the localised tidal flows, turbulence and wave conditions need to be assessed. Defining the precise layout also requires a detailed localised video assessment of the seabed to identify large boulders or other features which could interfere with the turbine and subsea base, and a geotechnical assessment to understand the localised geology must be completed.

The measurement of the tidal flows, turbulence and wave conditions in 6 localised positions will be the first activities to be undertaken by RTL. The initial deployment of temporary measurement devices took place in July 2014.

A second measurement campaign was undertaken during summer 2015. Localised video and geotechnical assessment was undertaken at the same time.

Further surveys are planned for 2017 and after further analysis the final turbine layout for the RTL 300MW project will be determined.  It is estimated that an area    2 - 3 square miles will be required for this project.

11.  Are the conditions in the Alderney Race too extreme?

The conditions are challenging for any kind of human activity within the Alderney Race.

The turbine and subsea base that will be supplied by OH for the RTL 300MW  project has been designed to be deployed from a purpose built deployment barge. This operation can be undertaken within a single tidal cycle (less than 6 hours) and requires no diver support during this operation.

The planning and design of the RTL 300MW  project will also have to account for stormy weather and heavy sea conditions including:

  • Interference with installation works during construction;
  • Increased surge loads on the turbine and foundation structure;
  • Increased fatigue on the turbine components; and
  • Reduced vessel accessibility during operation for maintenance

12.  What is the planned route for the FAB Link Cable?

After two survey campaigns the offshore cable routing has now been determined. 

Landfall assessments for Alderney have shown that Longy Bay and Corblets Bay are the most suitable areas for cable landing. 

13.  Will the cable landfalls change in appearance?

There will be no lasting change to the cable landfalls as the cables will be laid using either an open cut trench method or horizontal directional drilling (HDD).  The beach will be reinstated to its original condition once construction is complete. There will be temporary disturbances to the landfall locations for health and safety requirements during the construction phases.

14.  What do we expect to see during the construction of the projects?

During the installation of the FAB Link cable and tidal project shore landing cable, landfalls will be cordoned off and an open trench will be constructed or arrangements made for HDD.  The marine sections of these cables will be laid by a purpose designed cable laying vessel. Onshore cable will be underground and will predominantly run along public roads. The FAB Link onshore cable will run between 2 landfall locations and will have the ability to connect to an onshore convertor station. This convertor will act as the connection point for the export of tidal power and the connection point for the import of power into the existing Alderney electrical grid.

Turbine deployment will be via a purpose designed barge. This barge will be operated by a single tug. Several smaller support vessels will also be visible during deployment operations.

Cable that will connect the turbines together will be laid by a purpose designed cable laying vessel.

15.  Will there be any surface piercing devices?

The OH turbine and subsea base is a gravity design which removes the need to fix a pile structure to the seabed. The weight of the turbine and subsea base holds the position on the seabed. These turbines and subsea bases will be deployed with a depth of 35 - 40 metres. Therefore the turbines are not surface piercing.

The final site layout will determine if an offshore substation will be necessary to collect the power from the turbines before it is exported to the onshore convertor station.

During the design phase the requirement for an offshore substation will be determined. The specific type, either surface piercing or subsea, will be determine as part of the detailed design.

16.  How will projects following completion of the RTL 300MW  project be developed?

Following the development of the RTL 300MW project, ARE will then develop its licence area up to the maximum capacity of FAB Link’s capacity. The trading capacity for conventional power between the British and French markets will be 1 – 1.4 GW. The capacity for the export of tidal power is twice this, because tidal power can be exported to Britain and France simultaneously.

FAB Link could be capable of exporting a further 6 to 8 300MW projects.

Once consent for the RTL 300MW project has been granted, ARE will then seek to gain an approval for the remainder of its licence area within the Race. This consent and Environmental Impact Assessment (EIA) will be based on a generic project design envelope for the tidal turbines and associated infrastructure and not simply just one manufacturer’s turbine specification.

This design envelope will encompass the key parameters of any turbine and its support structures that could be potentially be utilised. This adoption of the project design envelope approach allows a meaningful EIA to be undertaken by defining the ‘realistic worst case’ scenario that stakeholders can consider in determining the acceptability, or otherwise, of the environmental impact of the project. As long as a project’s technical and engineering parameters fall within the limits of the envelope and the EIA process has considered the impacts of that envelope and provides robust and justifiable conclusions, then flexibility within those parameters is deemed to permissible within the terms of any operating consent.

This approach is known as The Rochdale Envelope. 

17.  What is the Rochdale Envelope?

The Rochdale Envelope is an approach to consenting and EIA, named after a UK planning law case (relating to a proposed business park in Rochdale), which allows a project description to be broadly defined, within a number of agreed parameters, for the purpose of a consent application.

This allows a certain level of flexibility while a project is in the early stages of development. As development progresses and more detail and certainty are available, further information regarding potential impacts can be provided.

18.  How will tidal connect to FAB Link?

The FAB Link cable uses high voltage direct current (HVDC) and the tidal power will be generated as high voltage alternating current (HVAC). The two are not compatible and you cannot just “plug” the two together. To enable the import or export of power from FAB Link, a converter station is required. The connection for the imported power onto the Alderney electrical grid will also require this converter station.

19.  Will Alderney get cheaper power if it connects to FAB Link?

The unit price of imported power from FAB Link will be cheaper that the cost of a generated unit of power on Alderney.

The price of imported power from FAB Link will be determined by a number of factors: market price per unit; transmission fees; and infrastructure operational costs on Alderney.

20.  If the tidal project is delayed does it mean that the Alderney connection to FAB Link will be delayed?

Alderney’s connection to FAB Link requires a tidal converter station. It is technically unfeasible to connect Alderney to FAB Link without this convertor station. If the tidal project is delayed, the Alderney connection will be delayed.

21.  Will the consenting process answer the interests / concerns of all stakeholders?

The consenting process requires that a full Environmental Impact Assessment is undertaken, the results of which must be reported in an Environmental Statement document. A project Decommissioning Plan must also form part of the operating consent application.

The consenting process will aim to assess the following stakeholder interests / concerns:

  • Modification to usual fishing locations and routes
  • Monitoring activities to be undertaken once the project is in operation
  • Effects on navigation, shipping and submarine operations
  • Effects on leisure boats and charter fishing activities
  • Incompatibility with other licenced activities
  • Environmental impacts
  • Commercial viability of the projects
  • Changes to ecosystems and tidal resource
  • Effects on migration routes and spawning grounds
  • Effects on tourism
  • Impacts on coastal and terrestrial landscapes
  • Impact on views
  • Economic advantages
  • Attraction of new opportunities
  • Effect on designated sites

This list is not exhaustive, but has been included to show some of the areas that will be assessed by the consenting process.

These effects of these interests / concerns could be positive or negative.

22.  What is the programme schedule?

 

Race Tidal 300MW  Project

FAB Link Interconnector Cable Project

2014

Initial site survey

Site selection

France – Alderney cable route survey

2015

Detailed site assessment

Environmental Impact Assessment

Alderney – Britain cable route survey

Pre-consent consultation

Environmental Impact Assessment

2016

Detailed Site Assessment

Environmental Impact Assessment

Feasibility and cable route studies complete

2017

Environmental Impact Assessment complete

Pre-consent consultation

Consent application submitted

Consent application submitted

Permits for offshore works achieved

Permits for onshore works achieved

Procurement of cable and infrastructure

Final Investment Decision

2018

Consent achieved

Installation of 1st phase cable and infrastructure

2019

Project subcontract to a utility

 

Construction

2020

Site mobilisation

Array cabling 1st phase infrastructure

Installation of 2nd phase cable and infrastructure

Commissioning of the  FAB Link cable and infrastructure

2021

Manufacture of 1st phase turbines

Array cabling 2nd phase infrastructure

FAB Link operational

Construction of Alderney Converter Station

2021/  2023

Turbine deployment

300MW project operational