A new tidal lagoon pilot project is hopefully soon to get underway in Swansea Bay in South wales, with a new government-backed review by former energy minister Charles Hendry (commissioned in February last year) saying this kind of power generation would be significantly cheaper than offshore wind farms or nuclear electricity plants.
Mr Hendry explained that this particular lagoon would cost well below other types of low-carbon energy across its 120-year lifespan, costing households 30p a year to finance. Bigger projects, such as one that’s been planned for Cardiff Bay, would need to have subsidy payments over a 30-year contract averaging out at £70 per megawatt hour, Bloomberg reports.
The new plant in Swansea will be the first of six to be built in order to harness the power of the tides and it’s likely that it could be commissioned by the year 2022, with the first project in place by 2028/29. An added benefit of this kind of power generation is that it could help tackle climate change head on – a study from Aurora Energy Research shows that if 25 gigawatts of capacity is commissioned by 2030, tidal energy could provide over ten per cent of the UK’s total power generation, thus allowing it to meet its carbon reduction targets.
It’s always interesting to hear about projects of this kind and it’ll be even more interesting to see how they choose to build this particular structure to ensure that it stands the test of time. Professor Marie Jackson from the University of Utah has already issued a warning that unless the correct material is used, the structure could corrode relatively quickly.
Speaking to the BBC, the expert explained that the steel used in conventional concrete to reinforce it could corrode after just 60 years and Roman-style concrete should perhaps be used instead to build the seawall as this material, made without steel or cement, could last for over 2,000 years.
“I think Roman concrete or a type of it would be a very good choice [for Swansea]. That project is going to require 120 years of service life to amortise [pay back] the investment. We know that Portland cement concretes contain steel reinforcements. Those will surely corrode in at least half of that service lifetime,” she said.
A few years ago, scientists from the University of California, Berkeley found that there is actually a secret ingredient in Roman concrete that might help explain why it is so very durable. According to the Daily Mail, the team used X-ray beams to study a reproduction of Roman volcanic ash lime mortar and discovered that this volcanic ash is able to create a crystal structure that actually prevents tiny cracks in the cement from spreading. What’s more, the use of strätlingite crystals in the concrete also showed no signs of corrosion, which would suggest that the material is also more stable.
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