Somewhat improbably, regardless of what happened at COP26 in Glasgow, there would appear to be a new surge of interest in tidal range power!

– A new local government initiative (coordinated by the recently-formed Western Gateway, including Swansea, Cardiff and Bristol) is setting up a new Commission to scope out potential for either a barrage or tidal lagoons in the Severn Estuary.

– The Blue Eden project (a private sector consortium in West Wales) has just announced plans for a new battery facility, a floating solar farm, and a 320MW tidal lagoon in Swansea Bay.

– The Welsh Government recently issued its Tidal Lagoon Challenge – with an announcement as to the outcome of this said to be imminent.

(All this is over and above the continuing interest in tidal stream technology, which I touched on in my last blog: http://www.jonathonporritt.com/cop26s-nuclear-sidebar/)

I’ve always been an enthusiastic supporter of tidal power. Back in October 2007, the Sustainable Development Commission (of which I was then the Chair) brought out ‘Turning the Tide’, a major report on the pros and cons of building a massive tidal barrage across the Severn Estuary, providing up to 5% of the UK’s electricity needs.

We concluded that the pros significantly outweighed the cons – notwithstanding the significant impact of such a barrage on birds and fish. The conservation NGOs hated it. Never one to miss a good media opportunity, Barbara Young, a former CEO of the RSPB, promised to blow herself up on the barrage were it ever to be constructed. Labour Ministers were more polite, but somewhat baffled.

I don’t stand by every single word I’ve written (or co-written) over 50 years (that would be embarrassing!), But 14 years on, I stand by every single one of the words in ‘Turning the Tide’. The fact that it was so controversial doesn’t make it any the less right – then or now.

In 2010, the Government’s Severn Tidal Power Feasibility Study put an end to the debate. Such a barrage was judged to be ‘too costly’, and subject to ‘chronic optimism bias’. This persuaded those diligent civil servants to include what amounted to a massive 50% contingency budget! If only such risk-averse caution had informed the financial appraisal of the nuclear power station at Hinkley Point C, now scheduled to come online in 2026 as the most expensive power station in the world – at around £23bn at the latest count.

But put that big barrage to one side – and focus instead on tidal lagoons.

With their customary inability to see what’s really going on beyond the Government’s latest nuclear wet dreams, our beloved mainstream media have completely missed the extraordinary story about the potential for massive new tidal lagoons – in the Severn Estuary, in Liverpool Bay, and in North Wales, between Prestatyn and Llandudno – generating around 10 GW (10,000 MW) between them. (Just by way of a comparison, that’s the equivalent of around 20 of Rolls-Royce’s wholly speculative Small Modular Reactors that the Government is so keen on – see COP26’s Nuclear Sidebar.)

The media’s ignorance/indifference may have something to do with the recent failure of a proposed tidal lagoon in Swansea Bay in 2020. This relatively small scheme was approved by the Planning Inspectorate in June 2015, and the Welsh Government was keen, but the Treasury pulled the plug on it – a massive blow to what could still be a huge industry for the UK.

Things have moved on a lot since the Government’s Feasibility Study in 2010. With great big civil engineering projects of this kind, it’s easy to assume that innovation is irrelevant. Unlike solar and wind, which have been literally transformed over the last decade through new technological development, tidal range power for most people sits in a ‘clunky and unfashionable’ box.

Think again! Recent developments in turbine and pumping technologies, allowing electricity to be generated on both the ebb and flood tide, reinforced by AI to help optimize generating efficiencies, indicate that as much as a 40% increase in overall output is now on the cards. That’s massive. Beyond that, improved construction techniques will significantly reduce both capital costs and carbon intensity, ensuring that the ‘carbon payback’ period is much shorter than some people have indicated. All of which will ensure the impact on both fish and bird populations will be far lower – even the redoubtable Barbara Young will be able to sleep easy under her RSPB duvet.

None of which is likely to be of any interest to Boris Johnson, Rishi Sunak or Kwasi Kwarteng, Secretary of State in BEIS. But it must be of some interest to Emma Howard Boyd, Chair of the Environment Agency, who recently took to task her boss at Defra (Secretary of State, George Eustice) for the UK’s chronic lack of preparation for the accelerating impacts of climate change – including much heavier rainfall and inexorably rising sea levels. ‘Adapt or Die’ was her compelling warning, following on from the terrible floods back in Germany back in August which led to the death of more than 220 people.

The latest Assessment Report from the International Panel on Climate Change earlier in the year confirmed that we are now facing a minimum of a one metre average sea level rise by the end of the century – now absolutely locked-in because of historical warming – and as much as two metres if we continue on our current emissions trajectory. Two metres! Massive civil engineering projects will be necessary all around the country to protect millions of people from the impacts of such a horror story – and nowhere will this be more traumatic than in the Severn Estuary, where the risk of very high tidal surges is enormous.

So here’s an ‘Adapt or Die’ recommendation for Boris Johnson: given that extensive sea defences are going to have to be constructed over the next 20 or 30 years, come what may, should we not ensure that we generate as much electricity as possible from such costly projects? All the major new tidal lagoons I referred to above will provide significant protection against rising sea levels – not as much as a barrage, but significant for all that.

As ever, it all comes down to money. According to the Tidal Range Alliance, the cost of these new lagoons can be assessed at around £100 a MWh, comparable to the estimated costs of any new reactor which may eventually get built at Sizewell.

On October 26th 2021, Secretary of State Kwasi Kwarteng announced that the Government intended to bring forward a new financing mechanism (the Regulated Asset Base – or RAB) as a way of addressing the very high capital costs of the proposed new nuclear power station at Sizewell C. If and when construction gets under way, a levy would be imposed on consumers to help cover the cost of construction – at least £20bn – to the tune of ‘a few pounds a year’. This has a huge impact on the cost of capital, theoretically making it much more attractive to private sector investors.

Geese and ganders come instantly to mind! If the RAB is ‘the best option’ for Sizewell, why wouldn’t it be an equally good option for tidal lagoons – and even a tidal barrage? This would bring capital costs for a lagoon right down, perhaps to as low as £40 to £65 MWh (depending on financial assumptions) – not that much more expensive than offshore wind (once the cost of the long sub-sea cable connecting to the national grid is included) and so much cheaper than nuclear.

Over and above the economics, tidal lagoons offer significant advantages over new nuclear: construction time is estimated at five to six years rather than 10+ years; the design life of tidal lagoons is about 120 years, instead of about 60 years for a nuclear reactor; and when a lagoon comes to the end of its useful life, that’s it – minimal decommissioning costs (unlike with nuclear reactors) and ZERO toxic waste needing to be kept secure for thousands of years (not least from rising sea levels) as will be the case with any new nuclear reactor.

Does the phrase ‘no brainer’ come to mind? It should. And that should make you question what’s really going on here, which clearly has little to do with rational, transparent policy-making. The power of the UK’s nuclear establishment continues to astonish.