Wales to be energy self sufficient by 2025

29 July 2008

Tidal power projects have previously been refused on the Severn Estuary, but due to growing evidence of climate change and rising fuel costs there has been an increased interest in acquiring energy through sustainable means. In an attempt to become entirely energy “self sufficient” by 2025 Wales is hoping to depend on wave and tidal technologies to provide half, and wind power to provide a third of Welsh renewable power.

A list of 10 proposed projects that could provide clean, green energy from the tide in the Severn Estuary is being considered.

The most high profile tidal project is the proposed Severn Barrage, which would connect Lavernock Point near Barry with Brean Down, close to Weston-super-Mare. It would work by building a 16km long barrage across the estuary effectively converting it into a hydroelectric dam. This would be achieved by placing a number of large concrete caissons across the estuary, some of which would house conventional hydro-electric turbines.

The electricity would be generated by allowing the incoming tide to pass through sluices in the barrage. This body of water is then held as the tide ebbs. When the water level on the seaward side of the barrage is low enough the water behind the barrage is released back to the seaward side through the turbines, generating electricity.

There would be locks in the barrage to ensure access to the docks upstream.

Secretary of State for Energy John Hutton claims “Harnessing the power of the Severn Estuary could be an engineering project of breathtaking scale and we will look at the full range of technologies and locations.”
Welsh Assembly Government Environment, Sustainability and Housing Minister, Jane Davidson said:
“The aim of the joint feasibility study is to look at all the potential options for generating renewable and sustainable energy from the huge tidal range of the Severn estuary. The potential here is great and the Severn Estuary is a resource that could help us make a significant contribution to the proposed UK renewables target of 15% by 2020.”

The proposals gathered will now be assessed and used to develop the draft Strategic Environmental Assessment (SEA) scoping report. This report will look in to what issues need to be covered to carry out the SEA.

The feasibility study will run for two years, costing approximately £9 million, and will be a two-stage process with a decision point at the end of each. The first stage work, likely to run until late 2008, will focus on high level issues and short-listing potential tidal power project options. It will reach a first view on whether there are any fundamental issues that mean the project cannot proceed. At this point there will be a decision to either stop the study, or to continue with evidence gathering and assessments.

The proposal has caused much controversy and hence the study will specifically focus on the environmental impact of the barrage, cost, impact on local businesses, and concerns regarding planning and consent.

The Severn Estuary is protected under the EU habitats and Birds Directive so any tidal power scheme would have to meet legislative requirements. The Severn Estuary is of National, European and International nature conservation significance – and so has been afforded the corresponding levels of legal protection. It is designated as both a Ramsar Site and Special Protection Area (SPA) under the EU Habitats Directive and is in the process of being designated as a Special Area of Conservation. The Estuary also comprises a series of Sites of Special Scientific Interest (SSSI).

However, the local economy may benefit from the project. There are many organisations that could be affected, including the ports on the Severn. Previous studies estimated construction of a barrage would bring with it a number of socio-economic benefits to the region, including job creation and inward investment. These will be looked at afresh together with potential negative impacts.

If the outcome of the feasibility study is a decision to proceed, extensive and detailed further work would be needed to plan and implement a tidal power project, and secure the regulatory consents that would be required.

The Cardiff-Weston scheme could have a generation capacity of some 8640 MW and an annual electricity output of 17 TWh/y (Tera Watt Hours per Year) or around 5% of UK annual electricity demand.

The Sustainable Development Commission report estimates construction costs of £15billion for a Cardiff-Weston barrage This cost was based on the last detailed estimates of the scheme in 1988 and 1990 respectively. This was then scaled up for inflation. The cost is therefore based on revised data. The BERR feasibility study will include a revised and detailed cost analysis.