The Proposed Tidal Lagoon
The development of a power generating tidal lagoon in Swansea Bay could see similar projects popping up around the UK coast if it is successful. According to the BBC, the project to build a plant that can produce 240 MW and provide electricity for over 120,000 homes has attracted investment from the Prudential who are putting in £100 million.
Prudential’s Chief Executive commented: "Prudential is committed to invest in infrastructure projects that benefit the national economy. We are also proud to play our part in the development of this world-leading renewable energy technology."
The tidal lagoon will take the form of a 6 mile long, curved sea wall that is designed to harness the energy of our coastline to drive specially designed turbines and produce a valuable renewable source of electricity. We’re used to seeing wind farms across our landscape and everyone knows that solar is a viable source of renewable energy, but tidal electricity generation has so far lagged behind, despite its huge potential.
Tidal has so far remained on the back burner because of the perceived costs for installation. Back in 2011, the Committee on Climate Change produced a report to say that the cost was too high and the yield too low, but since then it has become clear that their figures didn’t quite add up. That could see more installations being given approval in the next few years.
What is Tidal Energy and How Does it Work?
Most people know what a hydroelectric plant is. We have a few in the UK such as Ffestiniog Power Station in North Wales, and they work using the potential of moving water. They normally consist of a large dam which feeds water under high pressure to hit and turn a number of industrial size turbines. This energy is then fed into a generator and is used to produce electricity. It was one of our first sources of renewable, clean energy even before we became concerned with finding clean solutions to our power problems.
Tidal energy works in the same way. In fact, any moving body of water can be used to turn turbines that can then feed into some kind of generator. At the Swansea installation, bulb turbines will be placed at intervals under the sea wall. The water on the sea side of the wall will be higher than the water on the landside which means the power can be generated to drive the turbines enough to create a large amount of electricity. The system works both ways so that when the tide starts to go out, the water on the land side is higher than on the sea side.
One thing that might well sell the concept of installing tidal power plants is that they also provide a sea defence. With recent problems with coastal erosion and the damage done by storms last year, tidal walls can also protect the mainland whilst producing a valuable source of renewable energy.
The Benefits of Tidal Energy
The Swansea installation may be the first of six similar projects that are planned for the future, with other sites being considered around the coast including Colwyn Bay in North Wales and the Bristol Channel. The network could produce a staggering 30 TWh per year and cover almost 8% of the UK’s power needs.
One problem, however, is the cost. The Swansea installation is expected to be priced around £850 million and construction is going to take around 3 years, with the first energy production expected in 2018. But the Swansea tidal project may also provide income from more than just electricity. There are plans to develop sporting and recreation facilities around the installation and Tidal Lagoon plc believe that this, combined with electricity production, could yield a profit of £76 million a year, providing a quick return on investment over 12 to 15 years.
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The Future of Tidal Energy
Compared to its renewable neighbours like solar and wind power, tidal energy has largely been a marginal consideration in the past. That is set to change with a number of worldwide projects currently being undertaken that could see the technology surging ahead in the next few years.
Many scientist now believe that a series of tidal systems and estuary barrages could well provide as much as 20% of the UK’s energy resource if we embrace the available technology and push it forward. The problems that engineers face is that constructions need to be robust enough to cope with tidal extremes and, for a long while, the struggle has been to create a fortified installation that will not cost the earth in repairs when a storm hits the mainland.
Find out more about the history and future of hydroelectric power on our main site.
