The Tories point out that their manifesto promised to end subsidies to onshore wind, so they have a democratic mandate. We should remind them that it also promised to support Swansea Bay tidal lagoon! Now they must keep their pre-election promises.
Peter Scott's home is to be restored and opened to the public - a fitting tribute to one of the founders of the UK conservation movement.
The Wildlife and Wetland Trust's Slimbridge centre on the Severn, where Scott lived for over 30 years, was established in 1946 and has been conserving crucial habitats and enabling visitors to experience avian wonders ever since.
Discussions about harnessing the Severn tide have been going on even longer: the first parliamentary committee on this sat in 1926.
Most of the debate over the ensuing 90 years has been about a barrage, which would cause significant damage to habitats, birds and fish. A barrage is unlikely to be built, at least if the UK remains in the EU, because the compensation that would be required under the Habitats and Wild Birds Directives would not be achievable.
However, there is an approach which could use the Severn's tide - the second highest in the world - to generate electricity without breaking EU rules and (even more importantly) without causing widespread environmental destruction.
Instead of a barrage across the river, tidal lagoons could be constructed along the banks of the estuary. Lagoons essentially use the same technology as barrages: underwater turbines turned by the ebb and flow of the tide. But tidal lagoons can be created in ways which avoid such significant impacts to these most sensitive habitats.
Tidal Lagoon Power (to whom I am a consultant) have prepared proposals for lagoons off Swansea, Cardiff and Newport. The Conservative General Election manifesto promised that the Swansea lagoon would "soon be helping to deliver secure, affordable and low-carbon energy". This project was given planning permission in June 2015 - which was necessary, but not sufficient.
Less subsidy than nuclear for a wholly new, clean technology
The Swansea lagoon would be a global first of a kind. So it needs financial support. It would then generate electricity for 120 years, so the benefits would more than outweigh the cost. Indeed the company has suggested that the financial support received to get it up and running could then be repaid.
Under this approach, Tidal Lagoon Power would receive a loan, which would be repaid. It would also receive a 'Contract for Difference' (CfD) to guarantee the price received for its power. A good portion of the revenue received via the CfD could also be repaid over the lifetime of the project. This is currently subject to negotiation with government.
The Cardiff and Newport schemes would be cheaper, partly because of learning by doing and partly due to economies of scale. Lagoons could provide secure, entirely predictable renewable energy for over a century, at a subsidy level lower than that offered to EDF for Hinkley Point C. But the Government has yet to make a decision.
In early February the Government announced an independent review into the potential for tidal lagoon energy. This could be exciting, because the potential is large. But it could also be damaging, if used as a delaying tactic. Government has stated that negotiations on Swansea will run on in parallel. This is essential, because potential investors must not be deterred.
The Wildfowl and Wetland Trust supports the Swansea tidal lagoon. "WWT has long considered that the opportunities presented by the nation's tidal resources should be explored as one of a suite of other options for low carbon energy production", says its Conservation Director, Dr Debbie Pain.
"We also think that priority should be given to projects that can be delivered without significantly and irreversibly damaging the natural environment. This is why we were against a Severn Barrage, and also why ... we wrote a broadly supportive letter about the Swansea Bay lagoon planning application.
"If this lagoon goes ahead, it will tell us a great deal not only about how this technology can be used to produce low carbon energy, but also about how to manage and reduce the environmental impacts of tidal lagoons."
Lagoons will, of course, have some environmental impact. Any form of electricity generation has some environmental impact. The company is obliged under the Habitats Directive to implement measures to minimise disruption during construction and to provide compensatory habitats to replace designated features.
But Tidal Lagoon Power proposes to go further - not only to replace lost habitat but to improve environmental conditions. It is engaging with a range of conservation groups in order identify opportunities to work together on this. And the company is prepared to give substantial funding to this.
8% of the UK's power could come from tidal lagoons
Modern society uses a lot of electricity. Much more can and should be done on energy efficiency. But if we are to control climate change - the greatest threat to conservation and biodiversity as well as to humans - much more heating and transport will have to be electric rather than from gas or oil. So more generating capacity will be required. In the UK, not enough is being built. Indeed, it is not even certain that there is enough electricity generation capacity to meet existing demand.
Energy and Climate Secretary Amber Rudd got deserved praise when she said that UK coal generation would end by 2025. But she also said that this would only happen if it was consistent with energy security. Stories of the lights going out - every politician's nightmare - now appear quite regularly in the tabloids. If there is not sufficient alternative capacity installed, the UK will keep the coal fires burning.
Tidal Lagoon Power is considering schemes that would generate 8% of UK electricity (which, for comparison, is more than would be generated by Hinkley Point C). Each scheme will have different environmental impacts, all of which will need to be carefully assessed. The Environmental Impact Assessment for Swansea has been completed, though the actual impact will need to be monitored if it is built. An Environmental Impact Assessment for Cardiff is being done.
The company does not expect conservationists to give it a blank cheque and say that all lagoons should be supported. What is needed now is simply support for Swansea. If Swansea is built, other options can then be assessed and discussed. If Swansea is not built, no other lagoons will be built and the UK will carry on burning coal.
Now, talking about manifesto commitments ...
The Energy Bill currently being considered by Parliament - it has just passed through the Lords and is about to return the Commons - will end subsidies to onshore wind. This is, in my view, not a sensible policy, as onshore wind is the cheapest renewable energy source in the UK.
But the Tories point out that their manifesto promised to end subsidies to onshore wind, so they have a democratic mandate. We should remind them that their manifesto also promised to support Swansea Bay tidal lagoon!
They are implementing their negative mandate by halting the expansion of onshore wind. They must implement their positive mandate too. With the Bill now due to return to the Commons, it's time for MPs to amend the text with enabling clauses for the Swansea Bay lagoon - and shame the government into keeping its pre-election promises.
The first parliamentary committee on electricity from the Severn sat nine decades ago. Nothing has yet been done. Even by the standards of British bureaucracy, that is slow progress.
There are other technologies worth exploring for the Severn Estuary, such as sea fences. But they must not be used to delay the Swansea lagoon. Now is the time for David Cameron and George Osborne to catch the tide.
Stephen Tindale (@STindale) is a climate and energy consultant.