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The decarbonisation of heat requires a transition from gas boilers to low-carbon heating systems such as heat pumps. Efficiency gains can be achieved by linking heating systems through ambient loops called Fifth Generation District Heating and Cooling (5GDHC) networks. The UK needs working demonstrators to understand both the technical and practical challenges in the heat transition. The Balanced Energy Network (BEN) links two buildings on LSBU's campus and is the UK's first 5GDHC system at scale and among the first in the world to be retrofit in parallel to an incumbent gas system and include an active demand side response control system to toggle between energy vectors in way that minimises cost and carbon emissions. This paper presents performance data from its first year of operation in baseline mode, as it was commissioned and optimised. High temperature heat pumps were retrofit to an existing gas boiler circuit and match the 79 °C output temperature of the gas boiler system. No fabric upgrades were required and no pipes, ducts or heat emitters were resized, however the system maintained performance to reduce overall building carbon emissions by 13% and gas use by 40% across both buildings compared to the pervious heating season while the system was in use. • First known UK 5th Gen ambient heat network retrofit to existing buildings. • Demonstration of high temperature heat pumps (79 °C) maintaining a high COP. • Performance data from heat pumps retrofit into existing gas heating systems. • Demonstration of a phased transition from gas to heat pumps in complex buildings. • Up to 40% reduction in use CO2 emissions with opportunities to optimise over time. [ABSTRACT FROM AUTHOR]

Highlights • Evaluation on thermal & electrical energy performance for a Balanced Energy Network in London. • BEN energy performance jointly solved by measurements and simulations. • Assessment on BEN performance using a novel energy performance index: total system efficiency (TSE). • Diverse effects of HP COP, HP & borehole output temperature, TSE on energy performance. • Demand side response service: time of use electricity pricing used in BEN. Abstract In the UK up to 40% of total final energy use is accounted for by the heating and hot water systems, which makes up 20% of greenhouse gas emissions. One path to low carbon heating is to electrify heat, and then meet the electricity demand via a smarter grid. This article presents a novel approach to electrifying heat based on a balanced energy network (BEN) system located at the London South Bank University (LSBU) campus. The BEN system includes borehole thermal storage, an ambient temperature heat network (heat transmission and distribution), water source heat pumps, smart hot water storage, and demand side response (DSR) service. Its thermal and electrical energy performances were mainly investigated. A novel energy performance index (TSE: total system efficiency) was also proposed and applied in assessing the performances. Several key findings were achieved as follows: (1) The TSE varied from 1.4 to 2.2 in one of the coldest months of the year, indicating a great improvement on energy efficiency. (2) The ICAX high-temperature heat pumps in BEN operate with a higher COP fluctuating between 3.1 and 3.2 with a Carnot efficiency of 0.5. (3) With an acceptable level of thermal comfort, the BEN system can reduce CO 2 emissions up to 3.62 t for two weeks. (4) Corresponding with the initial design setting, 70 °C has been proved as the optimal operating output temperature of heat pump. [ABSTRACT FROM AUTHOR]

Approximately half of all energy consumed is used for generating heat and hot water in the UK, meanwhile, space heating and hot water consist of about 21% of greenhouse gas emissions. One pathway of decarbonizing heat is electrification of heat, the requirement of electricity is then met through smart grid and demand side response management. A new method for electrifying heat through a balanced energy network (BEN) system, which is situated in central campus of London South Bank University, has been presented. The validations of BEN model are performed against historic measurement data and manufacturer performance data. BEN system performance is then predicted and evaluated through investigating the effects of BEN and building internal factors including system operation mode, thermal storage, indoor set-point temperature, and COP of heat pump. Several key results were drawn as follows: (1) Carbon emissions from building energy consumption mainly depend on operation mode and thermal storage capacity of BEN system, actual heat demand in buildings and carbon emission factor as a function of time; (2) Energy consumption and costs and its carbon emissions will nonlinearly increase with the increasing of indoor set-point temperature; (3) In January (the coldest month of the year), the heating consumption for operating BEN system will be decreased by 77.9%/72.9% compared with historic monitoring data of 2014/2015; (4) For BEN system, the usage, costs and carbon emissions of electricity supplying to heat pump is an decreasing function of COP. • Prediction & Evaluation on system performance for a Balanced Energy Network in London. • BEN system performance jointly solved by measurements and simulations. • Diverse effects of internal factors of BEN & Buildings on system performance. • Carbon emissions depending on operation mode, thermal storage capacity & real heat demand. • Heating consumption decreased by 77.9%/72.9% for BEN comparing to 2014/2015 data. [ABSTRACT FROM AUTHOR]