Assessing savings potentials from changes in energy behaviours of hospital staff: benefits and challenges of energy audits

Behaviour change is increasingly considered as potentially cost-effective measure to reduce organisational energy use, while campaign evaluation remains a major challenge. Previous research has shown that especially in complex non-domestic buildings the variability in baseline energy use may often equal campaign effect sizes. In hospitals, evaluative attempts are further complicated by a prevalent lack of sub-metering. Surveying and energy audits are common tools to obtain information on buildings and organisational processes and identify energy conservation opportunities in the face of these obstacles. This paper investigates the viability of using energy audits as explicit resource to explore the theoretical potential of energy savings obtainable through behaviour changes of healthcare staff. Detailed audits of lighting and appliance use were carried out in 11 hospital departments for which plug loads and lighting consumption were also monitored at the distribution board level. Reduction opportunities from specific changes in energy behaviours were then modelled on their basis to establish ex-ante estimations for savings potentials. The method proved useful in ranking different end-uses to guide behavioural energy conservation efforts in hospitals. Usability was however limited by uncertainties remaining for data inputs from audits, both for power ratings and more importantly for usage hours and frequencies with which behaviours were currently performed. Detailed energy audits were hence found to be a workable tool for campaigns reforming protocols and procedures to eliminate redundant energy use, while they seemed less helpful for those promoting easy standard behaviours. For the latter, it seems advisable to consider additional methods of data collection as part of evaluative strategies depending on project aims, available budget, access to technical staff and the importance of respective end-uses

Financial viability of school retrofit projects for clients and ESCOs

Published by Taylor & Francis. The energy performance contracting market is potentially substantial but very little work has been undertaken to understand the characteristics of successful projects. This study uses a probabilistic analysis of four hypothetical projects in the UK schools sector under the 2014 policy regime, combined with qualitative interviews with practitioners, to explore the conditions for a viable project. It finds that the proposed approach has the potential to allow more detailed exploration of project structures and scope for creating greater understanding of likely returns and the factors affecting them. Evidence is found that the use of deterministic risk screening techniques such as simple payback results in viable opportunities being overlooked. The risk profiles for clients and contractors (energy service companies – ESCOs) are not symmetrical and they will each find different projects more attractive. The results suggest that greater consideration needs to be given to the precise risk allocation between client and contractor to ensure that likely returns are properly understood. This study demonstrates a method for exploring project characteristics that can be used to understand their impacts on the financial returns for clients and contractors

Reducing hospital electricity use: an end-use perspective

Hospitals are an energy intensive building type for which high energy costs and sector carbon targets increasingly prompt attempts to reduce operational energy use. But evidence is sparse and generic one-fits all solutions are problematic due to the complexity and the differing specifications of hospitals. This study therefore focusses on departments as unit of analysis. Five department types (operating theatres, laboratories, day clinics, imaging departments and wards) with differing energy intensities, operating hours and at different stages within the patient pathway are investigated across three case study hospitals of different building age and size (11 departments in total). Detailed audits of installations and use are undertaken to attribute measured departmental electricity use to different end-uses. It is found that lighting loads are dominant in low energy intensity department types, while intensive department types have high loads for specialist ventilation and laboratory equipment. Resulting energy reduction strategies consequently need to take account of these differing challenges, for which an analysis of contributing factors as suggested for example by CIBSE TM22 proved useful. The use of floor area weighted operating hours is proposed as metric for hospitals and other complex buildings which may be beneficial in understanding end-use contributions to total energy use and in highlighting the after-hours switch off potential of building parts in otherwise continuously operating environments

An epidemiological approach to simulation-based analysis of large building stocks

This paper describes a novel approach to building stock energy modelling: Individual building simulation models are autogenerated for each building in the stock, and the resulting set of virtual buildings is selectively sampled, simulated and analysed in much the same way that an epidemiologist might study a population through surveys and statistical analysis. A conceptual and software framework is described, along with initial case study results for a London borough

Parametric study and simulation-based exergy optimization for energy retrofits in buildings

The undertaking of building energy retrofits is essential for the reduction of energy use and carbon emissions at a national level. Nowadays, a number of construction methods and energy technologies that are available to practitioners require that the appropriate retrofit solution is identified to ensure long-term project success. A significant limitation of conventional methods that may be used to examine this (e.g. scenario by scenario) is that only a limited number of design scenarios can be evaluated which limits the potential for identifying the “best” designs. Furthermore, while the building sector has a large thermodynamic potential where most of the buildings' energy demands (especially space conditioning) can be met by low-grade sources, the associated exergy analysis method is rarely used in architectural practice. The following paper presents a simulation-based exergy optimization model, which aims to assess the impact of a diverse range of retrofit measures. Two non-domestic UK archetype case studies (a typical office and a primary school) are used to test the feasibility of the proposed framework. The objective optimization functions in this study are building energy use, exergy destructions throughout the building energy supply chain, and improvement of occupants’ thermal comfort levels. Different measures combinations based on retrofitting the insulation levels of the envelope and the application of different HVAC systems configurations (VAV, VRF, ground-source heat pump, air-source heat pump, district heating/cooling systems) are assessed. A large range of optimal solutions were achieved highlighting the framework capabilities. This approach can be extended by using the outputs in cost-benefit analysis and in thermoeconomic optimization

Talking about targets: How construction discourses of theory and reality represent the energy performance gap in the United Kingdom

Targets for energy performance in operation have been advocated as a solution to the well-documented mismatch between the expected and actual energy use of buildings. Although construction industry actors will be crucial in realising these targets, their response to them is currently under-explored. Augmenting research on how middle actors shape energy consumption, this paper examines how everyday talk in the construction industry sustains this mismatch, drawing on a study of a hospital construction project with targets for energy in use. It applies Gilbert and Mulkay's approach to discourse analysis, particularly their interest in “accounting for error”, to data drawn from interviews with actors across the construction project, observation of daily life on site, and an examination of written interactions. Findings show how actors make a discursive division between the “theory” and “reality” of energy use. Expressing scepticism about “theory”, in particular, allows them to rationalise problems with future operational energy consumption and thereby mitigate their professional liability. This division therefore perpetuates, rather than overcomes, the separation between energy in design and operation, displacing a more collaborative discussion of performance expectations. This challenges the assumption that targets for energy in use can be effective without accompanying changes in industry incentives and ways of working. This paper argues for more attention to the patterns of talk that are found in the construction industry, in order to uncover how this crucial set of actors will respond to new energy policy incentives

Encouraging energy efficiency in united kingdom independent retail? The case of the butcher, fishmonger and cycle-shop

The UK non-domestic sector accounts for 16% of energy use and major cuts are needed to meet a ‘net zero’ CO2 emissions target by 2050. Policy and research to date have focused on technical potential and there are gaps in understanding social contexts, which are key to energy efficiency improvement. Furthermore, SMEs have been overlooked, despite the need for concerted action here to meet targets. In this study, mixed-method case study research is undertaken with three independent retailers (a butcher, fishmonger and cycle-shop) to explore energy management and energy efficiency adoption. Building on the 4Cs “Concern, Conditions and Capacity within a Community” (4Cs) framework developed by Janda, this study has identified the interrelationships between Cs and explored the underlying factors that appear the be more important in determining responses to energy efficiency opportunities. Reflecting on the 4Cs, improving energy efficiency within this sector is complex, so it is perhaps not surprising that energy efficiency adoption has been low to date. This study highlights the importance of the ‘social’ within a socio-technical context. Whilst technical conditions are invariably the most important factor in engineering calculations of energy efficiency potential, they appear to be of considerably less importance than social contexts in practice. The findings suggest that a greater focus on social context within a socio-technical frame could help make future policy interventions more effective. Whilst some of these findings may be sector-specific, several are likely to be transferable to other SMEs, retail and hospitality organisations

Inequalities in exposure to indoor environmental hazards across England and Wales – can more energy efficient homes help?

Housing is an important modifier of outdoor environmental hazards due to features such as the amount of passive and active ventilation a dwelling receives, the proportion of the façade that is glazed and the building's thermal insulation levels. Using Artificial Neural Networks based on an indoor building physics model, we simulate indoor temperature and air pollution concentrations in ~15 million English and Welsh dwellings and assess how exposure to indoor hazards varies for different population groups. The model is derived using simulations from the dynamic thermal modelling tool EnergyPlus, taking a spatially-distributed housing stock as input. Results are linked to the latest 2021 Census data on area-measures of population demographics to assess if vulnerable subgroups bear a disproportionate risk from indoor environmental hazards. We find neighbourhoods in England and Wales with a higher proportion of infants, ethnic minorities and income-deprived populations experience higher two-day maximum indoor temperatures in summertime; whilst more ethnically diverse areas have elevated annual average indoor concentrations of outdoor-sourced PM2.5. Areas with a higher proportion of those aged 65+ had a lower standardised indoor temperature (SIT) in winter, increasing the risk of fuel poverty. We then implement a stock-wide, home energy retrofit, in line with national decarbonisation targets. Results suggest energy-efficient building interventions may exacerbate heat inequalities without the provision of external shading, but improve population exposure to winter indoor temperatures and indoor concentrations of ambient-sourced PM2.5