• Energy Research

The US Better Buildings Neighborhood Program (BBNP) consisted of 41 different versions of thermal retrofit programmes with a common structure and objectives. This created a natural experiment in thermal retrofit programme design. This paper uses qualitative interviews with programme organizers measured against third-party programme performance data to create a model of 14 programme steps that were common to all BBNP grantees. This model uses the experiences of programme organizers to define best-practice principles associated with each programme step. Five themes emerge from the programme steps: (1) programme design: local market features and suitable programme structures; (2) marketing and outreach: the processes of creating awareness versus personal engagement – how community-based social marketing is a key strategy in driving demand; (3) workforce engagement: the skills gaps across the supply chain; (4) financial incentives: the merits of grants versus loans – how to use them in combination; and (5) data and evaluation: best-practice techniques for both programme evaluation and enabling iterative programme adjustments. These principles create a template for an ‘optimal’ programme model for retrofit programmes with stated objectives similar to the US BBNP. The potential and limitations in extrapolating this model to UK retrofit markets are considered.

© 2021 Elsevier Ltd 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.

The Canadian government created the EcoENEGY Retrofit for Homes programme (2007–12) to improve residential energy efficiency and reduce emissions produced through energy use. The uptake of retrofits varied both spatially and temporally. This research examines spatio-temporal patterns of retrofit adoption to understand the drivers behind participation in the grant programme and assess how future grant-based programmes might improve the uptake of efficiency measures. Temporal analysis demonstrated continued growth of programme participation over its original period of availability, and this accelerated once the programme was extended for an additional year after its original closure date. However, some spatial correlations weakened, which may be attributable to changes in programme design during the extension period. Seasonal variation was also observed, with spikes in retrofit activity occurring in winter. A regression analysis for conversion rates in Ontario and British Columbia displayed significant positive correlations for high shelter costs (>30% of household income) and households occupied by usual residents (regular occupants). Population density, median property value (only in Ontario) and units that were recently occupied demonstrated negative correlations. Spatial variation at both the city and neighbourhood levels suggests a greater degree of programme customisation is required to ensure uniform building stock improvement.\ud \ud \ud \ud Policy relevance\ud \ud Domestic retrofit will be a crucial component of every developed nation’s net zero strategy. For example, in Canada and the UK, houses account for 13% and 20% of energy-related greenhouse gas emissions, respectively. This paper explores trends in the most recently completed national retrofit programme in Canada, demonstrating rates of adoption across the programme, the effects of programme design modification, and the value of an understood programme brand and format for uptake. Further, when faced with tighter deadlines, there is a weakening of the relationship between adoption and spatially linked attributes such as population density, and duration of occupancy. Conversely, a strengthening of the relationship with levels of education and household costs was observed in some jurisdictions. The evidence in this paper strengthens the case for long-term, actively managed retrofit programmes to enable the skills base and consumer interest towards market transformation.

The UK government’s Clean Growth Strategy unambiguously described the decarbonisation of heat as the UK’s greatest policy and technical challenge in meeting our carbon targets. Maximising the potential for energy efficiency in the existing domestic stock is critical to the low-carbon heat transition. Good information exists on the technical potential for energy efficiency measures in the UK stock, however, a lack of knowledge about current stock conditions and in-use factors places considerable uncertainty on how much of this technical potential is achievable in practice. \ud This study uses data from the fifth carbon budget (CB5) policy projections and updates the in-use factors using measured data from the National Energy Efficiency Database (NEED). This results in a 26% shortfall by 2035 in the anticipated energy savings through cavity, solid wall, and loft insulation compared to what is assumed in the CB5 projections. This will have costly implications for meeting future carbon budgets. Risks and policy implications are discussed. The practical potential for energy efficiency measures beyond cavity, solid wall, and loft insulation is explored.

© 2018 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 CO2 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.

There is an increasingly rich literature on the decarbonisation of heat and the evolution of heat networks. This paper investigates whether a novel fifth Generation District Heating and Cooling Network (5GDHC) could be retrofitted to an existing National Health Service (NHS) hospital campus for the purpose of heating and cooling. The building load was simulated and input into a custom-written script to carry out a series of parametric studies and optimise design options. The model was calibrated against site data available from hospital facilities management. The research found that it is feasible to use a 5GDHC consisting of a large single mass of water to utilise inter-seasonal thermal storage. A natural water resource such as an aquifer was not required. The model tested sizing options and found that larger thermal storage, heat pumps and chillers reduce operating costs and improve flexibility. The paper closes with a discussion of the practical factors in retrofitting 5GDHC networks to a densely occupied and highly constrained campus environment. The findings are novel in further describing the circumstances for which 5GDHC networks are suitable.

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.

How can programme design and strategy drive the decision actually to undertake retrofit upgrades? The US Better Buildings Neighborhood Program (BBNP) and the UK Green Deal both represent ambitious efforts to drive domestic retrofit markets. These programmes are compared and the differences in their conversion rates explored in the context of marketing, outreach and workforce engagement strategies. The impact of financial incentives is also explored. This paper supports the consensus that the US BBNP was successful against most of its stated objectives. The UK Green Deal, while slow to start, was gaining momentum before it was effectively ended. Semi-structured interviews with programme organizers give evidence that the Green Deal would have benefited from a more active approach to marketing and outreach, specifically emphasizing the distinction between the two. Marketing generates interest, but local outreach through word of mouth and personal referrals is needed to drive upgrades. The Green Deal did not sufficiently engage the workforce through an ongoing communication strategy and should have better facilitated both technical and non-technical skills development. The interest rate of the Green Deal is shown to be but one factor influencing participation, and can be effectively balanced through programme design in other areas.