Homes and the energy transition
Jenniy Gregory
Program Leader RACE for Homes
RACE for 2030
Presentation title: Tackling the challenges of upgrading over 1 million Australian Homes by 2030
Abstract: The relatively poor energy efficiency of Australian homes has long been identified in research. Our understanding of the economic, thermal comfort and associated health benefits that come with improving home energy efficiency is also not new. However, with electricity prices rising, the situation in existing homes is getting worse, especially for those suffering financial vulnerability. In addition, the poor thermal performance in Australian homes has a significant environmental impact from increased energy-related carbon emissions.
Less understood is the potential for synergies between improving home thermal performance and rooftop solar to shift heating and cooling demand from peak periods in the evening to periods of low net demand in the middle of the day. This can reduce energy bills and prices, improve household health and comfort, reduce stress on the grid and increase the capacity to install rooftop solar power.
So, how do we lower energy bills, mitigate climate change and the improve health and comfort of occupants related to improving the thermal performance of our homes?
This paper will explore the findings from the RACE for 2030 Opportunity Assessment, Enhancing home thermal efficiency and the research report Pathways to scale: Barriers to, opportunities from, and impacts of retrofitting one million+ homes. In addition, it will outline the RACE for 2030 proposed research project Energy Upgrades for Australian Homes. This project is intended to build on these findings to develop a coordinated, practical and equitable framework to reduce energy bills and carbon emissions and improve comfort significantly by upgrading millions of existing Australian homes by 2030. The research aims to develop initiatives including developing new business models, unlocking financing, development of supply chains and installer training and accreditation and potential for policy reform to address barriers which inhibit the large-scale rollout of energy upgrades in Australian homes.
Yo Han Kim
Research Principal (data analytics)
Institute for Sustainable Futures
Presentation title: How effective are the energy efficiency upgrades for vulnerable homes? Evidence from the Victorian Healthy Homes Program
Abstract: A project spanning the past four years, the Victorian Healthy Homes Program is the first randomised controlled trial of its kind in Australia designed to measure whether making a home warmer during winter leads to improved energy and health outcomes for vulnerable households.
The participating low-income households in Victoria were assessed and fitted with energy efficiency and warmth upgrades valued at up to $3,500. Energy billing data, indoor temperature readings, and surveys from 1,000 households across three years (2018, 2019, and 2020) were utilised in this study’s statistical analyses.
Results show that the average indoor temperature increased by a third of a degree across the day, and gas usage decreased by 5.5 kWh/day as a result of home upgrades. In practical terms, this equates to a reduction in exposure to cold temperatures (<18 °C) by 43 minutes per day, and reduction in energy bills by $85 per winter.
It should be noted that the health benefits measured in terms of reduced healthcare costs were much higher than energy benefits at $887 per winter, highlighting the need to consider both the health and energy benefits for intervention programs in low-income households. Economic analysis also showed that upgrade costs can be recouped within three years.
The results also demonstrated symptoms of rebound effect, where the scale of health and energy benefits differed significantly by groups. A notable difference was found in how the upgrades benefitted cohorts across the years. The 2018 group saw a large rise in indoor temperature (+1 °C) with no increase in energy use. For the 2020 group, the reverse was true; there was a large decrease in energy usage (~7 kWh/day) without notable rise in indoor temperature. Such heterogeneous outcomes point towards the rebound effect in play. The ongoing study will further investigate this rebound effect and will be able to provide more insights into its mechanism.
This study is unique in its rigour and transdisciplinary nature, integrating aspects of energy, social science, health, and economics. The results of this study present a holistic and measured evidence on energy and health benefits of home upgrade interventions, and will serve to underpin future programs that implement these home upgrades at a state scale for Victoria. Several unique challenges are also discussed, including the handling and analysis of confidential data, statistical methods in analysing survey responses, and integration of health and energy analyses.
Lygia Romanach
Research Scientist
CSIRO
Presentation title: Going beyond minimum residential energy efficiency requirements: Will Australian volume home builders lead the change?
Abstract: Expanding the market of energy efficient housing is important for a range of environmental, economic, health and comfort-related reasons. Despite these various benefits, previous research suggests that the building industry remains hesitant to embrace the residential energy efficiency market at scale. In Australia, volume home builders (VHBs) currently construct ~40 per cent of new detached homes, and in turn, they are often seen as a key catalyst for driving change across the industry. But the question remains: how interested, willing and motivated are VHBs to lead the residential energy efficiency market?
The current study aims to answer this question by exploring the current experiences of VHBs within Australia’s energy efficient housing market – including the perceived impact of higher energy efficiency requirements on business practices, processes and priorities; and prevailing perceptions of consumer demand for energy efficient homes.
To achieve these aims, eight semi-structured interviews were conducted online with stakeholders across Australia’s VHB industry between March and May 2022. The key qualitative insights from these interviews were supplemented by quantitative self-report data collected via a short online survey (n=7).
Key findings from research suggest that although the VHB stakeholders generally understand the benefits of improving residential energy efficiency, they currently perceive little to no consumer demand for energy efficient homes. At present, many VHBs therefore have few to no incentives to invest in residential energy efficiency beyond the minimum legislative requirements. During the interviews, stakeholders detailed how standardisation is fundamental to their businesses for several reasons (e.g. to reduce design/construction time and costs). In turn, there are concerns that increasing residential energy efficiency may (at least in the short-term) lead to higher building costs and supply chain disruptions due to the various changes that need to be made to a building’s design, envelope, construction and materials. Moreover, improving a new home’s thermal performance was seen to impose greater disruption to business supply chains than investing in renewable energy technologies such as solar photovoltaic panels, battery storage and electric vehicles charging stations, as the latter are often viewed as ‘easier’ to install and promote/market to consumers.
Overall, this study’s results suggest that at the current time, many Australian VHBs may lack the immediate motivation and incentives to build homes above the minimum residential energy efficiency requirements. Various strategies may therefore be needed to encourage VHBs to lead the change in Australia’s energy efficiency housing market and transition the industry at scale.