The National Grid supply type of Marine comprises the following:
The potential for both wave and tidal energy is huge, but there has been very limited utilisation of either and very little is planned for the future as shown in the graph. This is because both are seen as relatively very expensive to implement, and there are considerable operational challenges.
It is estimated that globally the annual potential for tidal energy is 1,200 TWh.
Two existing tidal barrages - one in France and one in South Korea - are effective in producing tidal energy.
However, two major issues greatly increase the cost of maintenance, and these make tidal energy a particularly expensive option:
- Susceptibility to damage from salinity and storms
- Difficulty of access for repair and maintenance.
In FES 2021 the capacity of marine power sources is expected to increase to a maximum of around 8 GW, with annual generation up to about 25 TWh. So, which projects may produce this increase in capacity from the current approximately 15MW to around 8GW, an increase by a factor of about 500?
Various projects have been discussed, and in some cases those discussions have been ongoing for some time, but at present none have approval. Some of the more significant ones are:
- Severn Barrage. 8.6GW. First suggested in the 19th century, but last declined in 2013, partly on economic gounds and partly for environmental reasons.
- Mersey Barrage. 700MW. A previous plan was abandoned in 2011, but the latest one received funding in early 2020. This will be used to progress planning.
- Swansea Bay Tidal Lagoon. 90MW. This project had a DCO (Development Consent Order) but is currently not going ahead, with the UK Government citing "value for money" reasons.
- Wyre Tidal Barrage. 160MW. Funding being sought to progress planning.
However, we are unaware of any significant projects that could be expected to increase capacity and generation in line with the National Grid's more ambitious figures.
Details of various prototype and demonstration projects are maintained and published by RenewableUK.
The estimated potential worldwide for wave energy annually is 29,500TWh.
However, the technology to implement effective wave energy capture is still at the early stages of development, and there are no operational installations yet. There are are some R&D projects in progress, notably in the UK.
We are currently unaware of any significant wave power projects in Great Britain.
Last updated July 2021