ENERGY NETWORK | BANKSIDE YARDS Bankside Yards Fifth-generation energy network Heat sharing Low-temperature fth- generation network allows energy sharing Optimised faades and efcient systems Optimised faades, systems and infrastructure, combined with energy sharing and green energy purchasing, will achieve net zero carbon in operation Air source heat pumps Air source heat pumps supplement heating and cooling energy balance across site Future-proofed Future connection to external district heat network infrastructure acts as a thermal store. In future projects we will use the ground for thermal storage, Amrania says, but in this instance it was not considered a cost-effective solution in terms of its high capex. With energy prices going up now, though, conditions for this option are becoming more favourable. Targets In terms of energy efficiency, Amrania believes the fifth-generation network being installed at Bankside Yards will provide unprecedented energy saving. With a third-generation network, you got network energy losses. And reduction of those losses relies essentially on the skill of the facility management [FM] team and how well equipped they are with knowledge to finetune the system and kit installed. With an ambient loop network, such as the one at Bankside Yards, you immediately save 30% to 40% on heat energy. Also, for example, because the network is operating at a low temperature, the coefficient of performance for ASHPs remains well above those of fourth-generation networks around 30% for a typical heat pump. These networks could be 50% to 60% more energy efficient than third-generation systems. The phased construction of the site means the full fifth-generation system is due to be completed and commissioned around 2027. Initially, the Arbor building will be using ASHPs for its standalone heating and cooling requirements, and will eventually be connected to the energy network as the building of the site progresses. With the ambient loop it is quite easy to phase in connections, says Amrania. ASHPs can be installed in the buildings individually, Railway arches have been incorporated into the design UPGRADING A THIRD-GEN NETWORK The ambient heat network in Lund, Sweden, connects multiple buildings at Medicon Village and is operated by energy company E.On. The network continues to employ a gas-red combined heat and power plant as the source of heat, reecting its conversion from a third-generation network. So why transition from the original third-generation scheme straight to a fth-generation network? Amrania says there are two key reasons. The rst is that a fourth-generation network still has quite elevated temperatures compared with a fth-generation ambient loop network. So any waste-heat capture in a fourth-generation network still has to be upgraded. If you capture heat from a transformer, say, it will be giving you around 20C, says Amrania, which would need to be raised to around 60C. In an ambient loop, that waste heat goes into the network, and can be absorbed straightaway, he says. Theres no need for additional energy to raise the temperature. Theres also no extra embodied carbon within the kit needed to upgrade the energy. Thats the key, says Amrania. and once the network is up and running you can connect them. The project team has developed a soft landings strategy to ensure a smooth transition as each building comes online and the phased switch to the ambient network takes place. There may be a few teething issues initially, as people come to terms with this new system, Amrania admits. Its a new system and a different approach, so theres a massive learning curve. But that has been built into our thinking and planned for, so that the FM team are well prepared to tackle these systems. Ultimately, when operational, the fifthgeneration network has been designed to use data to improve performance and optimise energy efficiency across the development. For example, the temperature maintenance system will eventually integrate elements such as weather predictions as well, so it can adjust heating or cooling for expected temperatures rather than reacting to current conditions. The whole idea behind the fifthgeneration network concept is that they begin as a fifth-generation network, but eventually, within a few years, once you accumulate the data it turns into a sixthgeneration network because it becomes data-driven, Amrania says. And the benefits? A significant increase in energy efficiency and energy saving, as well as helping to decarbonise energy and tackle the impact of the urban heat island effect. CJ References: 1 Thorsen, J E, Lund, H, & Mathiesen, B V, Progression of District Heating 1st to 4th generation (2018) 68 December 2022 www.cibsejournal.com CIBSE Dec 22 pp66-68 Bankside Yards.indd 68 25/11/2022 16:24