I am in Bristol today participating in an event to discuss the development of energy projects in the Severn estuary (see here).  It seems entirely appropriate that this meeting coincides with the final week of the global climate change talks in Paris.   We need lots of renewable energy to wean ourselves off fossil fuels and avoid catastrophic climate change.

The prize of generating large amounts of electricity from the considerable tidal power of the Severn (where the tidal range is the second highest in the world, being as much as 50 feet) has been long sought.  I have written about this on a number of occasions (for example see here and here) and was actively involved in the debate when the UK Government last looked at this seriously 2006-2010.  Concluding a study into Severn Tidal Power, the then Energy and Climate Change Secretary, Chris Huhne, said that there was no strategic case for government to support a tidal power project and it would not reopen the debate unless or until the strategic context changed (ie if the need grew or the cost of technology reduced).

Then, and now, the RSPB held the view that it was desirable to harness the tidal power of the estuary but in a way that did not cause needless harm to the natural environment especially given its importance for wildlife (it is protected for its wintering birds such as shelduck and Bewick's swan and fish species like sea lamprey and twaite shad).  We have argued that a strategic approach is needed to optimise the value of the Severn to people and wildlife.  This means fulfilling commitments to protect the heritage of the region whilst exploring ways of boosting the economic potential of the region and harnessing the tidal power of the estuary.  In 2010, our belief was that a solution would be found in innovative technologies rather than a traditional big barrage but that more attention should be given to nurturing the other considerable natural assets held by the estuary such as using the intertidal habitats to provide an efficient and cost effective solution to help protect people from coastal erosion, storms and flooding.  

Shelduck in flight (Ben Hall, rspb-images.com)

The debate about the Severn illustrates a wider debate about energy that we have been engaged in for nearly two decades.  Given the threat that climate change poses people and wildlife (see here), it is essential that we prevent atmospheric greenhouse gas emissions exceeding 350-450 parts per million thereby reducing the risk of global temperatures rising by 2 degrees above pre-industrial levels.  This is why we have, with others, campaigned for developed nations like the UK to move towards or a low or zero carbon economy by the middle of this century.  I am optimistic  that the deal struck in Paris will clearly signal that this is the direction of travel we are heading and that the energy revolution will need to speed up. 

We’ve long argued (in debates about wind, solar and tidal power as well as bioenergy) that this energy revolution needs to take place in harmony with nature.  We have backed this up with a number of projects designed to take a strategic approach to renewable deployment and in the new year we will publish a research report (see here) outlining how to deliver a low carbon, affordable energy future which has the least ecological impact.

In 2008, we commissioned Frontier Economics (Matthew Bell now CEO of Committee on Climate Change and Paul Johnson now CEO of the Institute of Fiscal Studies) to assess the economics of tidal power.  Their conclusion at the time was that there was sufficient capacity of cheaper alternative forms of renewable energy to meet government targets without having to rely on electricity from a tidal barrage (the graph below from shows the cost of producing different forms of energy £ per Mega Watt hour).  In the end, the Government agreed.

In recent months, I have been excited and encouraged by the vision of Tidal Lagoon Power which has sought to generate large amounts of electricity (up to 6 GW) through the installation of four lagoons at different points in the estuary.  Those promoting the scheme say that the technology is environmentally benign.  The first lagoon (in Swansea Bay) has been through nearly all its planning permission hoops (see here) and if it is built we think it would be an opportunity to test the technology and assess its environmental impacts to inform the installation of subsequent lagoons.

Yet, it may be all still come down to economics once again.  Government wants to keep energy bills low and so it will support the cheapest forms of renewable energy.   It tries to achieve this through what it has called its Levy Control Framework using a combination of measures such as Feed in Tariffs and Contracts for Difference.  The latter allows the Government to provide a finite amount of financial support to cover the gap between the strike price of different energy generating technologies and the wholesale price.  The recent fall in the price of oil and gas has reduced the wholesale price, so the financial hole that the Government expects to have to fill has grown.  The cost of projects that it supported in February this year is shown in the graph below.

Comparing this graph with the one generated by Frontier a few years ago, you can see how the costs of generating electricity has changed - the cost of solar power for example has reduced dramatically from >£350 per MWh to c£50-80 per MWh.   I understand that the strike price for tidal lagoon would be £96-105 per MWh which is at the upper end of the scale but arguably still competitive with offshore wind.

We are clearly on a low carbon trajectory and we still need a large slug of renewable energy:  the Committee on Climate Change recommends UK emissions reductions to an average 57% below 1990 levels by 2032. 

So, it could be argued that the strategic case for government support of a tidal power scheme (both in terms of need and cost) has changed and, in the Swansea Bay Tidal Lagoon, we have the prospect of testing whether it as environmentally benign as it people say it is.  

I expect the debate at today’s event will feel very different to the slightly stale one we had nearly seven years ago.  There is greater respect and understanding about the need to develop the estuary for both people and wildlife and a previous Sustainable Severn event in 2013 concluded  (here) that an incremental approach was needed to develop energy projects in the region in balance with existing environmental and economic assets and interests.  The objective of the Forum today is to find a way to help turn this ambition into reality.   

I'll let you know how we get on...