The Engineer

Upfront costs mean tidal power scheme unlikely to go ahead

News

A tidal power scheme in the Mersey Estuary could deliver enough electricity to meet the average needs of more than 200,000 homes, but the high construction costs mean that it is unlikely to go ahead.

Following many months of studies and investigations, a preferred scheme has been identified by a team commissioned by Peel Energy and The Northwest Development Agency (NWDA) — a barrage across the river between New Ferry (Wirral) and Dingle (Liverpool).

It would be designed so that the turbines within the barrage would generate power in two ways — from ebb tides only as well as from ebb and flood tides; and from a range of water-level differences (operating heads) across the barrage. This choice of scheme would minimise effects on the Mersey’s protected inter-tidal habitats.

Multiple navigation locks would need to be included to accommodate large commercial ships and small leisure craft. Other facilities that could be included in the scheme include a visitor centre, a pedestrian/cycle path, a light public-transport link and a tidal-turbine research centre.

But the studies also found that the estimated £3.5bn upfront construction costs result in a cost of electricity that is not competitive in the current energy and capital markets.

Anthony Hatton, Peel Energy’s development director, said: ’In the longer term, once the upfront capital costs have been paid off and for the rest of its 120-year life, the cost of electricity would be very competitive. But the preferred scheme is unlikely to attract the necessary investment while the emphasis in the financial sector and renewable-energy incentives is on technologies that provide short- to medium-term returns.’

Mark Atherton, head of energy and environment, NWDA, said: ’The feasibility work has provided a valuable insight into how tidal-energy schemes could be operated in the future to deliver wider economic impact, while minimising the potential environmental impact. Some of the lessons learnt from the work undertaken are applicable not just to the Mersey Estuary, but to other estuaries in the Northwest and UK.’

Peel Energy started looking into the possibility of generating power from the Mersey Estuary in 2005. In 2006–07 a pre-feasibility study was undertaken in partnership with NWDA and supported by the Mersey Basin Campaign. This concluded that a number of tidal-power options had the potential to make a significant contribution to the UK’s renewable-energy targets. In September 2009, the full feasibility study was launched by Peel Energy in partnership with NWDA.

The study has now been published on the project website at www.merseytidalpower.co.uk.