Plaid on the Severn Barrage

This week ministers in London and Cardiff made an announcement on the latest developments in the quest for renewable energy from the Severn Estuary. A shortlist of 5 proposals now goes out for consultation, with additional funding made available for the further development of untested technologies. The Assembly's Environment Minister updated the Assembly yesterday. This was my contribution to the debate and the minister's response:

Leanne Wood:

Minister, no-one would dispute the need to harness the vast energy in the Severn estuary, but the challenge is how to optimise the renewable energy and the carbon emissions cut as quickly as possible with minimal environmental damage. I welcome your statement that funding is to be available for further development of the untried and untested technologies, and I welcome the news that consideration will be given to combining some of the shortlisted schemes. However, I hope that some of the five unsuccessful or undeveloped technologies may feature as part of a combination of schemes. For example, the Royal Society for the Protection of Birds is particularly keen to see the tidal reef scheme, as you will be aware, and it says that that would have the least environmental impact. Could a tidal reef be combined with a smaller barrage and a series of lagoons?

One factor that should also be taken into consideration is the need to compare damage in terms of carbon dioxide emissions that the various schemes would cause during the construction phase. Most Members will be aware that scientists increasingly assess that we have less than 100 months to bring carbon dioxide levels down to 350 parts per million in the atmosphere, or face uncontrollable and irreversible climate change. There is much unity among scientists that carbon dioxide cutbacks must begin immediately.

Yesterday, I attended the stakeholder event in Bristol where we were told that the Cardiff/Weston barrage proposal would not be constructed before 2020. Do you have information about how much carbon would be emitted through the construction process at the large barrage over the next decade, and possibly longer? The next decade is crucial for drastically reducing our carbon emissions. There have already been too many years of talk on this matter, so, within the next decade, we need to take some serious and drastic action.

Can the smaller options be constructed more quickly and with fewer carbon emissions? Can we have a number of these options in combination with each other, to maximise the renewable energy output with minimal damage to the natural environment?

Jane Davidson:

There are a number of parameters that are being explored through the next phase of this study. You said that things needed to happen as quickly as possible, but if they happen quickly and are not the most effective schemes, they will not give us the greatest benefits. We are actually running an agenda through to 2050, not to 2020. It was clearly explained in the session yesterday—I am delighted that you were there, as an Assembly Member—that it is unlikely that the biggest scheme, the Cardiff/Weston barrage, would be completed before 2022, but that the reef proposal, for example, could take even longer than that, because of the innovative nature of the proposal. Therefore, we must evaluate, all the way through this, the marriage between the renewable potential and the environment consequences. That is the fundamental element that needs to be evaluated.

You asked specifically about the carbon dioxide emission reductions in terms of the Cardiff/Weston barrage. It is estimated that the barrage would save 7.2 million tonnes of carbon dioxide emissions per year and that the construction impact would be compensated for in eight months of operation.

For more see John Dixon's blog.

Image taken from the BBC.