What is the PLA's position on Heat Source and Cooling systems?
The Port of London Authority is supportive of alternative energy solutions in line with sustainable development, national policy and relevant consents. However we have a duty of care to make sure all proposals have minimal impacts on the use of the port, navigational safety, the environment and the river regime.
Can the Thames be used for heating and cooling?
Recently the Department for Energy and Climate Change (DECC) published a heat map which demonstrates that the Thames has some potential to be used as an energy source. Currently there are a number of systems in place on the Thames. There are a number of types of installation, for example closed loop and open loop systems, combined heating and cooling or separate.
The challenge applicants have faces previously appears to be keeping the underwater structures like intakes, clear while meeting the requirements of the eel regulations, without creating a hazard to navigation.
What do I need to consider for an application to install a system on the Thames?
During a River Works Licence application the PLA will consider a number of potential impacts, some examples which are listed below.
The PLA would expect any application to consider the effect of any structures within the river on the safety of navigation. Any such structure should not be in the navigational channel, and not significantly decrease the depth of the water for passing vessels.
Any installation will need to consider the impact it may have on scour and accretion both by operation and construction. Designs must also consider the risk of the fine silt in the Thames, entering and blocking structures, and ongoing maintenance which might be associated with this.
The DECC heat map indicated where there are statutory environmental designations only, it does not indicate metropolitan and local sites of environmental importance, nor migratory species using the estuary. The PLA would expect any applicant to consider all and any impact that the development might create in the local area both during construction and operation.
Effects of a thermal plume (body of water significantly different in temperature to the Thames) must be limited as much as possible. It will not be acceptable to heat a significant cross section of the Thames as this creates a barrier to fish migration and could sterilise the area.
Screens will need to protect migrating fish from being sucked into the system as they migrate during specific periods in high numbers and the system could remove a significant proportion of the population, depending on design and screen choice.
There will be a number of consents that may be material to the consent from the PLA EA – The Environment Agency may issue up to three consents for this type of construction and would also be an approval body for a compliant Water Framework Directive assessment that may be required. All relevant consents will need to be in place prior to the works commencing.
- Abstraction Licence - This will cover the abstraction of water from the Thames. The EA consider open loop application as a non consumptive activity because the abstracted water will be returned to the river. The licence will have specific conditions linked to fish screens and approach velocities to protect eels and fish from being sucked into the intake pumps. The minimum requirement could be a mesh size/bar spacing of 1-2mm with an approach velocity (not exceeding) 15 cubic metres per second.
Environment Permit - Discharge - This will cover the discharge of water back into the River Thames. The EA is like to include specific conditions linked to the temperature at which the returning water can be discharged. These conditions will place restrictions on the temperature of the cooling water (discharge of heat) back into the river:
- Maximum return temperature of 28 degrees cannot be exceeded
- Maximum variation in temperature between abstracted water and discharge water which cannot exceed a variation of 10 degrees
- 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.
- 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.