How to harness the tidal power of the Severn Estuary

I’ve just finished reading a new review (the Hendry Review) on the Role of Tidal Lagoons. I think it is a considered piece of analysis that takes into account the many issues at stake in a place as precious for wildlife as the Severn Estuary.

In particular, I am delighted to see that the Review has taken on board the RSPB’s recommendation that the planned tidal lagoon at Swansea acts as a test project or “pathfinder” project from which we can learn the lessons ahead of a wider push to develop further lagoons in the Severn Estuary and elsewhere in the UK.

Hendry has recognised the potential opportunity of renewable energy from tidal but I’m really pleased that he is backing a measured approach such that if lagoon technology is to be expanded there is time to fully understand environmental impacts and avoid or mitigate them, so that this technology can be deployed in harmony with nature.

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

A key objective for the Governments of the UK is to decarbonise our energy supply. In 2008, the UK Government introduced a legally binding target to reduce greenhouse gas emissions by at least 80% by 2050 against 1990 levels. To achieve this our energy system will need to change, and we will need to significantly increase our use of renewable energy sources.

Last year ‘The RSPB’s 2050 energy vision’ looked at how we could do this. This was not a prescriptive document and we remain open to new ideas, innovations and technologies as the world works to meet the targets set out in Paris in 2015.  As the UK transforms its energy system to meet the Government’s 2050 climate targets, our belief is that it must be in harmony with nature.

As well as being a key focus for tidal lagoons, the Severn is one of the UK’s natural wonders.

These habitats providing winter feeding grounds for up to 76,000 waterfowl and waders (such as shelduck,  dunlin, redshank – all with Internationally important populations) according to the Wetland Bird Survey (WeBS) count.

And, in the water the Severn is home to 110 different fish species, including seven migratory species (among which are three of the five known UK breeding populations of twaite shad, as well as sea lamprey and river lamprey – all of which are internationally important).

And that is just a snapshot of the amazing wildlife that inhabit or use the Severn and adjacent areas. So, as you might expect we are protective of this precious habitat.

The RSPB supports the Swansea lagoon proposal subject to the outstanding environmental questions for example the potential impacts on fish, being satisfactorily resolved. We have long urged that lessons are learned from this first scheme so that we can fully understand the environmental impacts and mitigation potential of this technology to inform any future developments. I am therefore pleased to note the emphasis the Review places on in depth monitoring and research to learn these environmental lessons. 

The Review goes on to suggest the development of other small scale schemes from which further lessons can be learned. If Government chooses to adopt this approach, we see it as absolutely essential that the right coastal locations are selected for these projects, taking into account the likely wildlife impacts from the outset. The role of the National Policy Statement (NPS) will be key to selecting the right locations as will the role of a new Tidal Power Authority should Govenrment choose to adopt the recommendation to establish this body.  It is essential that this process, is subject to the rigorous tests of UK wildlife law.

The challenge to address climate change is so great that we need an energy revolution and tidal lagoons may have a role to play. The Review concludes that tidal lagoons would help deliver security of energy supply and help us meet our decarbonisation commitments.

I believe that if we learn the lessons from the Swansea Bay lagoon project, and understand how to deploy this technology in an ecologically sensitive way, tidal lagoons can play a role in decarbonising our energy future. However, this is a new and expensive technology; it must also not distract from the need for continued investment in existing affordable alternative and potentially more sustainable sources of renewable energy. And it absolutely must not cause needless harm to nature and fabulous sites like the Severn or our other precious estuaries around the coast of the UK.