Bristol Old Market Heat Network was one of the seven successful heat network schemes to be awarded HNIP funding at the start of 2020.
The area in Bristol was identified as an opportunity to decarbonise a substantial number of buildings as part of plans to meet net-zero emissions targets. The network will utilise a net-zero carbon heat source – a 3MW water source heat pump.
The heat pump is currently being manufactured however with significant lead times, the end of the Renewable Heat Incentive in March 2021 is a concern. The proposed amendments to the RHI scheme to enable tariff guarantees after this date are therefore welcome. The network itself is now approximately 20%* complete and construction is continuing with social distancing measures in place. This followed a review and approval of the risk with revised method statements to ensure contractors are kept safe during the process. The project was initially behind schedule as BCC held firm on procured NEC4 terms and the initial contractor appointed, therefore, did not proceed.
Following this, the DHN team have embraced the project management and collaborative approach of the NEC4 contract with a new contractor.
After continuing to work over recent weeks within a much quieter city, the project has been able to make up for lost time, demonstrating just how much can be achieved with a collaborative approach.
The delivery contractors have adopted a unique approach to social distancing with three different teams working on the construction phase but staying in three different hotels in order to adhere to recommendations. Bristol has also been using an innovative VacEx excavation method which has been delivered at a similar cost to traditional excavation methods in the current circumstance. The benefits of Vax-ex are that it is highly mobile, responsive and safe. The majority of “cost” on DHN civils is commonly not actually in the digging, but in under-utilised plant/labour as ground conditions and congestion changes. The Vac-ex allows work phases to adjust levels and progress through congestion much faster and safer than hand-digging, but needs to have an experienced/competent PM and Contractor to ensure the commercial benefits are realised. The use of Vac Ex is certainly a decision taken on a project by project basis when managing risk.