Renewable energy

Energy from tidal currents and run-of-river is 100% renewable and apart from a small operational and maintenance energy overhead and the CO2 generated in manufacture and installation, is completely free of CO2 emissions. Energy from flowing water is predictable and has a high energy density; this makes it suitable for the supply of base load on the electricity grid. Unpredictable renewables such as wind require equal capacity of fossil fuel powered power generation to backup installed wind generator capacity when the wind does not blow. This results in redundant capacity and therefore wasted capital and also a continued reliance of fossil fuels.

By 2020 the UK Government has committed to 20% of its total energy requirement coming from renewable sources. Of this it is estimated that 3% will be from a combination of tidal and wave devices. Marine renewables have the potential of providing 15 -20% of the UK’s energy needs. However, for tidal stream technologies there are significant limitations imposed by the current front runner technologies preventing the UK from reaching this potential sooner, these are:

  • Restricted number of sites with the right combination of depth, tidal flow and proximity to grid connection.
  • Cost of energy is currently too high due to high capital and O&M costs.
  • Perceived environmental impact.

Projections for the future

The Carbon Trust’s ‘ (http://www NULL.carbontrust NULL.co NULL.uk/emerging-technologies/technology-directory/marine/pages/background-on-marine-energy NULL.aspx)Future Marine Energy (http://www NULL.carbontrust NULL.co NULL.uk/emerging-technologies/technology-directory/marine/pages/background-on-marine-energy NULL.aspx)’ report predicts that in the UK 2.5gigawatt capacity will come from Marine Renewables by 2020 delivering 7 Terawatt hours per year; this is equivalent to1250 2MW turbines assuming a 40% utility factor. This is predicted to increase to 18 Terawatt hours, 3211 2MW turbines, by 2050. Assuming all available sites around the UK are utilised by 2050, the quantities of turbines will reach a plateau of around 3200 installed turbines. Assuming a service life of 10 years, the manufacturing rate of the entire sector to satisfy this requirement would need to reach 320 units per annum by 2045, see graph below.

Installed UK tidal turbines

Manufacturing levels would then need to remain at 320 units per annum to meet demand for turbines to replace those reaching the end of their service lives. Taking foreign markets into consideration, this figure would be considerably higher.

G-T’s competitive advantages will-mean that we will be well placed to take a significant proportion of this market; we estimate we will achieve 10% penetration of the UK tidal turbine market. With markets developing in Canada, North America, South Korea and Europe there will be significant export opportunities. In turn this would equate to a revenue of over £100 million a year by 2020

However there is also an unidentified market for ’free flow’ river turbines that could be installed where-ever there is an appropriate fast flowing river or weir. In the UK alone there are records of there being 5,000 watermills over the centuries and we would expect many of those sites to be suitable for our proposed technology. The Environment Agency has issued a recent report estimating there are about 4,000 ‘barriers’ (usually weirs) in the UK that are “win – win” schemes capable of generating about 1,800 GWhrs per year. Also the UN has identified a need for renewable electricity in remote communities in the Developing World, much of which could be supplied by in-river generation. We see significant early markets in Brazil, China and India.