A UK Government-commissioned independent review of Tidal Power development has backed a start on the proposed small-scale “pathfinder” £1.3bn tidal lagoon in Swansea Bay – with Penarth/Cardiff next in line.
If Swansea is successful there would be then a prompt start on the far-larger Penarth/Cardiff power tidal lagoon.[ PDN is using the term “Penarth/Cardiff” because the southern wall of the lagoon would be built out to sea in line with Penarth Pier.]
The independent report by Charles Hendry says tidal power will make “strong contribution” to the UK’s energy supply – and moving ahead with Swansea will be what he calls a “no-regrets policy” .
If Swansea is satisfactory, a further 5 additional tidal lagoons would be developed at Penarth/Cardiff, Newport, West Cumbria, Colwyn Bay and Bridgwater Bay – with the plans for Penarth/ Cardiff being the most advanced of the five.
The Penarth/Cardiff tidal lagoon at Cardiff would deliver “around 5.5 TWh” of electricity [ TWh = Tera Watt Hour , One terawatt hour is equal to a sustained power of approximately 114 megawatts for a period of one year.]
The report also suggests the scheme would “offer improved flood protection for the area as well as opportunities for sports and nature conservation”. The report says the developer with submit plans for the consent to build the Penarth/Cardiff Lagoon next year – in 2018.
The report anticipates that the Penarth/Cardiff lagoon could create 11,482 new jobs
But there are also snags :-
The report admits that no tidal lagoons have yet been built anywhere in the world and therefore it is “not possible to give an absolutely factual assessment of full life-cycle of environmental consequences” . It says that the Severn Tidal Power Feasibility Study highlighted a consensus that there are “challenging environmental issues to be overcome if tidal power generation of any kind is to be deployed.”
Mr Hendry says that developers of tidal lagoon sites will have to “make good the loss of existing habitat for wildlife in order to comply with the Habitats and Birds Directives” and says that the Penarth/Tidal Lagoon would “require a very significant amount of such “compensatory habitat’”.
Wildlife Trusts told Mr Hendry that “We have serious concerns that there are plans for a potential three lagoons in the Severn Estuary;” The report says it is likely that the Penarth/Cardiff lagoon “would result in significant impacts to the site and be difficult to consent in a manner compatible with the Habitats and Birds Directives”
Because four of the proposed new power-generating tidal lagoons will be in the Severn Estuary, there could be what are described as “cumulative consequences” and a potential “build-up of ecological impacts” .
Mr Hendry heard evidence that ” tidal lagoons in proximity to each other could produce less electricity as a result of complex negative hydrodynamic interactions.” – and that the “hydrodynamic effects of tidal lagoons could still be felt many tens of miles out to sea.”
As far as the Severn Estuary itself is concerned Mr Hendry says ” There is inevitably a point where the retention of such significant volumes of water will have a detrimental impact on the interests of other legitimate users of the estuary, in particular the ports, where their business requires them to be able to make full use of the tides (especially high tides) for shipping movements.”
POWER PRICES :
To be viable. the Penarth/Cardiff Lagoon will require an electricity “Strike Price” in its first operating year in a range of: £105-£120 per Mega Watt hour . [PDN Note: This is far higher than the “strike price” offered for the new Hinkley Point nuclear power station which is at £92.50 per Mega Watt hour]
The report recommends that the Swansea Lagoon “pathfinder project ” should be “commissioned and be operational for a reasonable period before financial close is reached on the first larger-scale project .” [which would be the Penarth/Cardiff lagoon].