The recent battering of our coasts with high tides and strong winds is a useful reminder of the amount of carbon-free energy that could be available if we make the necessary arrangements. The good news is that at last it looks as though someone is attempting to do so.

As with most schemes to produce carbon-free electricity, the French have beaten us to it – not only with their 59 nuclear power plants, compared to our 16, but they also have the first tidal flow scheme in the world, on the river Rance estuary in Brittany. It was opened in 1966, is run by EDF, has now paid for itself, and produces cheaper electricity than nuclear power.

There has been talk for years about building something similar in the UK, a barrage across the Severn estuary, perhaps from Porthcawl in south Wales to Lynmouth in north Devon. It’s likely to be very costly – about half the HS2 expenditure – and could destroy many environmental areas. On balance it’s probably not the best way of producing six per cent of our electricity – the equivalent of three nuclear power stations.

It seems that tidal power development in this country will need to depend on an interested entrepreneur and one has just stepped forward with plans for a different approach. Chinese-speaking Mark Shorrock is an environmental venture capitalist, specialising in clean energy production and energy efficiency, and he has been working on a series of tidal lagoons. The first one is in Swansea Bay and its completion date is 2018.

The plans are now in for consideration and they could well be accepted. They involve constructing a ten kilometre wall with big bags of sand covered in stone to enclose a lagoon, to provide electricity production and a sports and leisure facility. The 10K race round that wall will be a windy one!

So three million tonnes of rock and one million of concrete will provide around 240 megawatts of electricity, for 14 hours a day, using the daily high and low tides. Despite costing around £800 million to build, it will last for more than a century and be very dependable.

While the times of the tides are fixed, their heights aren’t, so there will be more power at spring tides than at the neap ones, and it would be possible to use the spare electricity to produce gas that can go into the national grid.

There is the opportunity to build ten such lagoons around the country, with different high tide times, to produce half our average electricity demand at a similar price to nuclear power.

Together these technologies could help make our electricity supply completely CO2-free.