Widely anticipated, the decision by the UK government to mothball plans for a giant tidal barrage across the Severn Estuary should come as no great surprise. Projects designed to tap the huge tidal range at the river’s mouth have been mooted for perhaps a century, and in such financially constrained times the government cannot be blamed for shying away from what is potentially a £34 billion (US$50 billion) drain on the public purse. A punishing austerity program will not stretch to such grandiose ambitions, even if such a development would have supplied some 5% of the country’s total energy demand from its 8,640 MW of generating capacity and satisfied a major slice of its carbon reduction and renewables commitments.
Aside from the huge investment cost, the potential environmental impacts were cited as a major issue in calling time on this latest proposal, a factor that many in the environmental movement saw as reason to condemn the plans from the outset.
The costs, risks and financial implications were simply too much to bear and, indeed, the government is most likely correct in its assessment that any potential investment in such a major undertaking is ultimately better spent elsewhere in the battle to shift toward a low-carbon energy complex.
Perhaps more importantly, the government cited the feasibility study that flatly concluded that the proposal would be costly to deliver and that it would be “very challenging to attract the necessary investment from the private sector alone.”
It is this observation that highlights an issue that must be of concern to the broader hydro industry: the question of private investment into the renewable energy sector and where such investment should then be spent. Of course, the best way to attract private investment is to deliver a good return, and the best way to deliver a financial return is to maximise efficiency, especially in these challenging economic times.
In this edition, we highlight some of the ways hydro plant owners and operators can increase efficiency and thus potentially enhance their economic returns. For instance, in our cover story on page 12, we take a look at a method for minimizing the lifetime cost of ownership for generators by more accurately predicting their service life and related maintenance costs. Meanwhile, the efficiency and operational benefits of an early consideration of the turbine main shaft seal in the design process are made clear in our feature on page 24. And on page 20, we hear from the Akosombo project in Ghana, where upgrading the station’s thrust bearings improved reliability by reducing operating temperatures and eliminating recurring cavitation damage.
Despite the failure of such an ambitious hydro scheme as the Severn Barrage to attract its big ticket investment, with these three examples and the many more besides inside this edition of HRW, the hydro industry is quietly proving itself a safe bet every single day.
David Appleyard - Chief Editor