South Tyneside Council implemented a district heating scheme for its high-rise residential blocks in the 1970s and it has continued this tradition in recent years with three major District Heating Networks of which Viking Energy Network Jarrow (VENJ) will be the first to be completed. This scheme will be a key component in the Council’s drive to become carbon neutral by 2030, with an estimated 1,000 tonnes of carbon dioxide being saved per annum, significantly contributing to the Councils carbon neutral ambitions.
Heat networks can address the ‘energy trilemma’ by meeting the following strategic aims:
- reduce greenhouse gas emissions using a wide range of low carbon and renewable heat sources
- improve security of energy supply by diversifying the energy sources for heating and reducing dependence on fossil fuel imports
- offer a supply of heat that is good value and that contributes to reducing fuel poverty.
The new energy centre is to be built on an existing council owned brownfield site at Jarrow Staithes on the south bank of the River Tyne on the outskirts of Jarrow. The centre serving the proposed energy network project will extract water locally from the River Tyne and use water source heat pump (WSHP) technology to feed a district energy network.
The energy centre and associated district heating and power network is a UK-first project and will provide low-cost, low-carbon energy direct to nine connected buildings via a dedicated network of pipelines and power cables, with allowance for future expansion. Combining a number of renewable measures, the scheme will help deliver annual carbon savings estimated at 1,000 tonnes and save around half a million pounds a year.
The centre serving the proposed energy network project will extract water locally from the River Tyne and use water source heat pump (WSHP) technology to feed a district energy network. River-water will be drawn through a system of rotating filters then flow through a heat exchanger before returning to the river about 3 degrees celsius cooler downstream. On the other side of the heat exchanger, the heat pump uses refrigeration technology to compress and upgrade the temperature to levels suitable for heating buildings.
Heat pumps usually produce between 2 and 4 times the amount of heat that they consume in electricity, depending on the design and installation characteristics. This is known as the Coefficient of Performance (CoP). Similar heat pumps are used in Drammen, Norway provides 75 per cent of the heat for the local heat network at temperatures up to 90 degrees celsius, saving considerable oil boiler fuel emissions.
The heat pump will be supplemented by a gas fired combined heat & power unit (CHP) when load is higher, such as winter mornings and evenings. The electricity generated by the CHP will be fed by a private wire network to the Council operated buildings and the heat generated will be fed into the heat network. Modelling shows that demand for electricity and heat both rise in winter and the peak periods for both often coincide. An electrical storage battery and thermal storage system will also be used to maximise the use of low carbon heat and electricity.
The heat pump will use ammonia, a non-ozone depleting refrigerant at high pressure with zero global warming potential and the heat produced will be distributed within a DH network with a whole system life expectancy of 50 plus years.
The locally installed solar farm will contribute to the electricity supply. Surplus electricity generated by the CHP and the PV will be stored in this storage battery for later release to the private network.
The proposed operational strategy utilising the electrical generation and battery storage will mean that the WSHP will run on a carbon neutral basis for much of the summer periods for domestic hot water generation for the connected network buildings. The private wire network will enable surplus solar PV power to be used in Council buildings, notably a listed town hall which would be difficult to add renewable to, and some winter evening peak charges to be avoided.
A design consultant was appointed following a competitive tendering exercise through the NEPO 212 Framework Lot 8 for Mechanical and Electrical Design services back in April 2019. This team developed the design to RIBA Stage 4a, and assisted in the main OJEU ITT & tender documents. The main contractor was appointed in March 2021 following planning permission award, and is now on site with construction expected to be complete by the end of 2022.