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To Build A Barrage…

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The much-discussed Severn Barrage is back on the agenda with a new plan by Hafren Power. REM hears what the company has to say about it.
To Build A Barrage…

The new scheme for the Severn Barrage appears to take into account and address the various environmental considerations that plagued previous proposals. Hafren Power is actually a company that was specially created to develop and operate the barrage which will be funded through private finance. Nevertheless, there are still concerns about the effect on habitats as well as various other issues to be addressed. For this reason Renewable Energy Magazine approached independent consultant David Betteridge who is currently assisting the company with its external communications, just to ask a few pertinent questions….

How is this Severn Barrage proposal different to previous proposals?

I think we’re talking about comparisons with the one DECC studied in 2010.  The difference is significant.  It proposed ebb-only generation – holding back a massive head of water and releasing it through around 200 turbines positioned in the middle of the estuary.

We propose ebb and flood generation (resulting in nearer normal estuary tides) through 1,026 bi-directional, slow-spinning (about 9 m/s tip speed) turbines across the whole width of the estuary. 

This preserves about 60 per cent more inter-tidal habitat than before.  In fact, we estimate the area of wetlands lost would approach that expected to be lost anyway as a result of rising sea levels. 

Slower tip speeds and fish passes (perhaps with fish directed by sound, light or bubbles) will minimise the impact.  Zero harm is the goal. Our engineers are confident that new technology, especially in turbine design, can solve the problem.

We have pledged to work with conservation organisations over the months and years ahead to get it right.   Overall, we will invest up to £1 billion in compensatory wildlife / habitat measures.

What contribution to the UK energy mix are we talking about here in terms of generating capacity and amount of CO2 displaced from UK emissions?

The installed capacity would be 6.5GW.  Typically the barrage (or tidal bar) will generate for a little over 15 hours per day – equating to 16.5TWh a year, or 5 per cent of the country’s electricity requirements.  It will deliver predictable and secure energy for at least 120 years, the minimum life of the structure.

It will complement nuclear, gas, wind, biomass and other generation sources.  It will help the country meet its renewable targets.

Overall save 7.1 million tonnes of carbon per year.

Several environmental groups, including the RSPB, have just recently come out, again, against the idea of a Severn Barrage, is there any way at all you can see that their concerns can be placated, either by modifications to your current plan, or by the production of a new one? Or do you think they will oppose the idea whatever plan for a barrage is produced?

In most cases, opponents are referencing previous proposals.  Our proposal wasn’t fully public until we submitted our detailed paper to the committee, to the same deadline as everyone else.

We believe we can satisfy environmentalist opponents, given time and in some cases further research.  For example, there isn’t a full picture of fish life available. We will ask Swansea University to do this study and we want to work with NGOs to agree how to protect the fish.  See the fish passes example above.

Could the barrage replace the need for new nuclear plants at Hinkley Point, or do you see it more as complementing nuclear?

The barrage will complement not replace.

How will this project be financed?

All upfront costs will be private sector – we have sovereign wealth fund and other infrastructure investors waiting in the wings.  They want long-term returns.  To invest, they need the certainty of a hybrid bill and an agreement from the government to guarantee the electricity price in the first 30 years.  We’re looking for a strike price similar to (but probably lower than) offshore wind. Possibly lower than nuclear.  As you know, negotiations are commercially confidential.

Uniquely, unlike other generation, the barrage will protect tens of thousands of properties from tidal floods, storm surges and rising sea levels.   This cannot be factored into strike price but is worth billions in damage averted and flood defences over the years.

Given the recent fuss in the media about offshore transmission licences for offshore wind, will there be any danger of significant costs being passed on to bill payers, and if so how much are we talking?

Government will want to get the best deal for consumers.  We need a guaranteed return in the early years to satisfy investors.  It should be perfectly possible to reconcile.   We will then have a barrage that will thereafter generate the cheapest electricity in the country – some £20/MWh for 90+ years.

We also anticipate relatively easy connection to the National Grid, at both ends, when compared to some other forms of renewable generation.

What level of support have you had from politicians and the government so far?

Mostly very positive – from David Cameron who we briefed last summer, to the Welsh Assembly and some English local authorities.   The backing of the Energy & Climate Change Committee is of course important.

Carbon-free generation isn’t the only appeal – a £25 billion private sector boost to the economy, 20,000 jobs in the construction phase and a legacy of calmer, clearer estuary waters leading to more recreational use are also factors.  Plus flood defence.

What models are there overseas for the success of this project? Including with regard to wildlife and habitat protection?

In a world powered by oil and gas, tidal power has been overlooked. Times are changing. We believe Britain can be a leader in this field, exporting know-how world-wide.

The barrage at La Rance in France (operational since 1966 and producing the cheapest electricity in France) is testimony to the basic approach.  No turbines have needed replacing.  It also attracts some 50,000 visitors a year. 

Less than a decade after construction the estuary was richly diversified with over 70 fish species, 110 worm species, 47 crustacean species and 120 bird species.  However, there is no reliable “before” picture to draw a full conclusion.   

As mentioned above, we have pledged to work with conservation organisations over the months and years ahead to get it right. Overall, we will invest up to £1 billion in compensatory wildlife / habitat measures.

Further information:

Hafren Power

Evidence submitted to the Energy & Climate Change Committee

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