What is the PLA's position on Tidal Energy?
The Port of London Authority is supportive of alternative energy solutions in line with sustainable development, national policy and relevant consents.
The Port of London Authority would consider the use of the river for energy generation providing that the installations and supporting infrastructure do not have an effect on other river users, the functioning of the Port, or the environment. The Authority has received a number of approaches from innovators wanting to install tidal energy in the Thames, therefore we have produced the indicative guidance below for companies to consider for their design, before approaching the PLA to install any items in the river.
Is the Thames capable of providing the right conditions for Tidal Energy?
The Thames has one of the larger tidal ranges in the UK however it is also a busy waterway and the fastest tidal flows tend to be in the deeper parts of the river which are also used for navigation. Public navigation, in particular smaller recreational vessels, are not constrained to the advertised channel and so appropriate areas of potential are broadly limited to the edges of the river where water depths and maximum flow rates are much less (Fig 1).
Fig 1. Numerically Modelled Depth Averaged Tidal Flows in Gravesend Reach
Previously studies have been carried out, using a ADCP fixed system monitoring flow rates over a spring tidal cycle in 1m water depth at low tide and 8m at high tide. It is felt that the recorded flows are indicative (Fig 2) of the potential that is available, recognising that different locations will have their own unique characteristics. Any application to install tidal energy on the Thames would be expected to minimise its effect on the river and its users. Further information on water depths can be found on the authorities published charts which are freely available at: http://www.pla.co.uk/Safety/PLA-Hydrographic-Service-Published-Surveys.
|HW TIME||VELOCITY (m/s)||DIRECTION (degN)|
In 2016 to support the Thames Vision the PLA has undertaken a detailed model of where flows reach 1m/s for more than an hour in a tidal cycle. Modelling excluded the navigational channel to avoid any interaction with most river users. The results indicated that there are limited areas where the flow is sustained from long periods, however if technology develops there may be cost beneficial opportunities on discrete sites. The overview of the areas studied is below. Please click on the relevant area of interest to view the findings in more details.
If developers, site owners or engineers wish to develop projects for tidal energy on the Thames they are welcome to review the data and discuss the site with the PLA. Any application would have to follow the advice detailed below.
The full methodology in developing the assessment and conclusions can be found here.
What would a project need to apply to install machines in the Thames?
The PLA would like to see the following when considering a tidal energy application for installation of River Works Licence:
location on a chart, including:
- that indicates the depth is suitable for the installation, and
- cable direction and width of trench to land
- Details of the installation including dimensions of the actual structure, moving parts, and effect on water displacement.
- Hydrodynamic assessment to demonstrate that the energy lost by the system does not leave sediment up and downstream of the installation, and the moving parts will not erode the bed.
- Method of installation of cable and protection, turbine or machine
- Maintenance of machine
Details of all other consents applied for:
- The Marine Management Organisation (MMO) is the appropriate authority to confirm whether the development requires an EIA.
- Final consent, by way of a Marine Licence, will also be required for any structure in the river by the MMO.
- Flood Defence consent – If developing or constructing within a specified distance from the flood defences or through them; please consult your local officers or Land Drainage Byelaws for clarification.