Energy trade association RenewableUK calls the UK "the undisputed global leader in marine energy." If plans for a tidal lagoon in Swansea Bay go ahead, that claim will be reinforced. Tidal Lagoon Swansea Bay would be the world’s first man-made energy-generating lagoon and could power over 155,000 homes.
Renewable energy is, of course, an area of huge importance and growth. A 2011 study by researchers at University of California-Davis and Stanford University suggests that the world could be powered completely by clean energy within 20-40 years.
Of the renewable options available, tidal is particularly intriguing. Renewable UK says wave and tidal energy could produce around 20 percent of the UK’s current electricity needs, and that the ongoing reduction in its technology costs will make it increasingly viable from a commercial perspective.
Swansea Bay has a high tidal range of up to 10.5 m (34 ft), making it an ideal location for tidal power generation. The proposal would see a 9.5 km (6 mi) lagoon wall constructed, halfway round which would be a 550 m (1,804 ft) turbine housing. The turbine housing would provide a means of allowing water to flow in and out of the lagoon as the tide rises and falls. Up to 26 turbines would be contained in the housing and would be driven with the flow of water in and out of the lagoon.
The Tidal Lagoon (Swansea Bay) development group says the lagoon would provide an energy production capacity of 320 MW and would provide sustainable and predictable electricity for 120 years of operation. In addition to generating electricity, the lagoon would provide opportunities for arts, culture, education, recreation and conservation activities.
Naturally, watersports such as sailing and rowing would be possible in the lagoon, along with cycling and running around the lagoon wall itself. A visitor center will provide a place to learn about tidal power and the construction of the lagoon, whilst a community marine farm would be created in the shallows of the lagoon. It is thought that the lagoon would also help to stimulate local regeneration and the creation of jobs.
The lagoon has been accepted for consideration as a Nationally Significant Infrastructure Project. Planning and marine license decisions are expected in early 2015.
The video below provides an introduction to the project.
Source: Tidal Lagoon Swansea Bay
The tide has two slack periods a day, periods when no electricity can be generated because the water is almost stationary. In fact if you plot the generated output of such schemes you get a square wave like form - from nothing, then a rise which falls back to nothing repeated twice a day. Absolutely no good for base load, in fact not much good for any real load without the power station backup.
Financially, how would that solution work as compared to a nuclear power plant?
Also, will it be able to provide the same amount of energy 24/7, and if not, what's the backup plan (which, obviously, can't be a fossil-fueled power plant)?
> A 2011 study by researchers at University of California-Davis and Stanford University suggests that the world could be powered completely by clean energy within 20-40 years.
I guess "energy" here means "electricity": How likely will we have electric trucks, cargo ships and airliners in 20-40 years?
Where I live (South Dakota) 65% of our electricity is from renewables.
http://www.cebr.com/reports/tidal_lagoons-2/
Its one of 6 planned tidal lagoons for the UK, which will produce energy at a similar cost to new nuclear power plants, and a lot cheaper than the daft windmills they have stuck all around our coast. If all 6 come into operation it would supply approx 8% of the UKs annual electricity needs.
and more info from a detailed report:
"Of course a tidal lagoon does not generate electricity ‘baseload’, and other capacity will be required to provide electricity when the tide is turning. However the requirement for this will be known in advance and so its provision can be planned and optimised in advance.
Because high and low tides occur at different times around the coastline, then a portfolio of appropriately - sited tidal lagoons would have a much smoother generation profile than a single lagoon, thus reducing the requirement for generation from other sources."