Tidal Lagoon Power Generation Scheme in Swansea Bay - White Paper PDF Download Link

Tidal Lagoon Power Generation Scheme in Swansea Bay

A report on behalf of the Department of Trade and Industry and the Welsh Development Agency

Executive Summary
Tidal Electric Limited (TEL) has proposed the construction of a 60MW “tidal lagoon” power generation scheme in Swansea Bay. TEL has estimated that the lagoon could be constructed for £81.5M and generate power at a cost of ~3.5p/kWh.

Renewable energy generated at this cost would be commercially very attractive and both the Department of Trade and Industry (DTI) and the Welsh Development Agency (WDA) have separately undertaken reviews to assess the claims made. The two reviews, undertaken independently, arrived at the same main conclusion.

This was that the generation costs of the proposed tidal lagoon would be substantially higher than TEL’s estimate. The most significant differences between TEL’s proposal and the Reviewers’ assessment are as summarised in the following table:

Thus, the total construction cost for the proposed tidal lagoon scheme is likely to be around £234M, compared with the TEL estimate of £81.5M (i.e. an increase by a factor of 3.6), and the lagoon is only likely to generate around 66% of the energy projected by TEL.

The cost of energy from the proposed lagoon is therefore estimated to be more than 4 times greater than that presented by TEL.

On this basis the cost of energy from the proposed lagoon would be at least 17p/kWh at 8% discount rate which conforms with results from previous studies of tidal lagoons undertaken by others.

The Reviewers see little prospect for reducing the cost of energy from this concept through replication, innovation or experience as it would uses standard engineering principles and mature technologies. The cost of the lagoon is dominated by the materials cost where there is little prospect for cost reduction and much scope for cost increase.

There are also proposals to construct tidal lagoons in other locations, such as off the coast of North Wales. Whilst this review has not studied these other proposed schemes, the issues surrounding the Swansea Bay scheme are sufficient to cast doubt on the economic viability of the tidal lagoon concept for the foreseeable future.

The few possible locations with a higher tidal range offer a greater annual power output, and larger lagoons may offer some economy of scale. Studies of tidal barrages, however, have shown that the economies of scale are relatively minor whereas the potential for unacceptable impacts tends to increase with size.

Should TEL’s engineering solutions prove deliverable, then the economics of all the potential tidal barrage schemes around the UK would also be significantly improved.


No comments:

Post a Comment