Mithra Moezzi

Better home energy audit modelling: incorporating inhabitant behaviours

Building energy modelling is often used in US home energy audits to assess a homes energy performance and to determine energy-efficiency retrofit recommendations. These models promise quantitative, engineering-based, defensible information on a homes energy retrofit opportunities. Modelling is based on assumed standard use behaviours, despite highly variable energy use practices. This research reports on tests that incorporate household behaviour in home energy audit modelling, based on a sample of single-family households that received a utility-sponsored home energy audit in Seattle, Washington, a US city with a cool temperate climate. The use of a compact set of self-reported behaviours in place of standardized behavioural assumptions improved the match between actual home energy consumption and model estimates, and shifted retrofit savings predictions. These were modest improvements over the initially poor match, but highlight the opportunity for better customizing home energy audit modelling by using simple information on household behaviours. A comparison of modelled savings of heating-related conservation actions shows that energy savings from moderate behavioural changes are on par with retrofits for many homes. These steps provide a gateway to modelling household behavioural changes alongside retrofits, and a means to bring behaviour into conversations with homeowners and into the technically oriented efficiency paradigm in general.

Is Efficiency Enough? Towards a New Framework for Carbon Savingsin the California Residential Sector

The overall implementation of energy efficiency in the United States is not adequately aligned with the environmental benefits claimed for efficiency, because it does not consider absolute levels of energy use, pollutant emissions, or consumption. In some ways, promoting energy efficiency may even encourage consumption. A more effective basis for environmental policy could be achieved by recognizing the degree and nature of the synchronization between environmental objectives and efficiency. This research seeks to motivate and initiate exploration of alternative ways of defining efficiency or otherwise moderating energy use toward reaching environmental objectives, as applicable to residential electricity use in California. The report offers three main recommendations: (1) produce definitions of efficiency that better integrate absolute consumption, (2) attend to the deeper social messages of energy efficiency communications, and (3) develop a more critical perspective on benefits and limitations of energy efficiency for delivering environmental benefits. In keeping with the exploratory nature of this project, the report also identifies ten questions for further investigation.

Documentation of Calculation Methodology, Input data, and Infrastructure for the Home Energy Saver Web Site

The Home Energy Saver (HES, http://HomeEnergySaver.lbl.gov) is an interactive web site designed to help residential consumers make decisions about energy use in their homes. This report describes the underlying methods and data for estimating energy consumption. Using engineering models, the site estimates energy consumption for six major categories (end uses); heating, cooling, water heating, major appliances, lighting, and miscellaneous equipment. The approach taken by the Home Energy Saver is to provide users with initial results based on a minimum of user input, allowing progressively greater control in specifying the characteristics of the house and energy consuming appliances. Outputs include energy consumption (by fuel and end use), energy-related emissions (carbon dioxide), energy bills (total and by fuel and end use), and energy saving recommendations. Real-world electricity tariffs are used for many locations, making the bill estimates even more accurate. Where information about the house is not available from the user, default values are used based on end-use surveys and engineering studies. An extensive body of qualitative decision-support information augments the analytical results.

Grid Dependencies and Change Capacities: People and Demand Response Under Renewables

Much of everyday activity in highly technologically developed societies involves electricity from a centralized grid. This is most evident during blackouts—at which point the availability of many routine forms of information, communication, light, money, and other connectors are quickly depleted. The expectation of perfect electricity has accompanied an evolution of social practices that absolutely require a working electricity system, while practices that escape that system become abandoned or antiquated. By definition, during supply shortages, societies adapt. In less-developed countries, especially those experienced with unreliable power, and with less-dense ties to the grid, there is established capacity to cope, including substituting non-electricity for electricity, and adjusting the timing of activities. In areas that expect perfect electricity, and rarely experience failures, however, reliance on electricity is higher and coping is more fragile. Drawing on social practice theories and history of technology, this chapter explores examples in the evolution of the grid dependence and develops a concept of sociotechnical resilience. Sociotechnical resilience refers to the degree to which basic activities can be decoupled from the grid, and how they do so. This resilience obviously matters in the case of blackouts and severe supply restrictions, but it also speaks to flexibility within “portfolios” of practices in terms of their synchronization with electricity supply. Demand flexibility is expected to become increasingly important in future scenarios where electricity supply has evolved to include much higher penetrations of renewables. To date, most of the debate on how this flexibility will occur has focused on “demand response,” particularly through individual end-user behaviors, and well as through isolated and largely private backup systems to provide temporary power. Focusing instead on sociotechnical resilience broadens the scope of flexibility by looking at people, technologies, and adaptation in a more connected and intricate combination. In addition to the power markets and generation capacity markets that already exist, there is thus a need to recognize, maintain, and further develop the sociotechnical capacity to do without electricity. This possibility is rarely included within the usual boundaries of debates about the renewables and the grid, or balancing supply and demand. To illustrate, the chapter provides examples from supply disruptions in both more-developed and less-developed countries, explores how policies, language, technology design, and the public sphere might better recognize and build this sociotechnical capacity.

An Assessment of the U.S. Residential Lighting Market

This report provides background data upon which residential lighting fixture energy conservation programs can be built. The current stock of residential lighting is described by usage level, lamp wattage, fixture type, and location within the house. Data are discussed that indicate that 25% of residential fixtures are responsible for 80% of residential lighting energy use, and that justify targeting these fixtures as candidates for retrofit with energy-efficient fixtures. Fixtures determined to have the highest energy use are hardwired ceiling fixtures in kitchens, living/family rooms, dining rooms, and outdoors. An assessment of the market for residential fixtures shows that nearly half of new residential fixtures are imported, 61% of new fixtures sold are hardwired, and about half of all new fixtures sold are for ceiling installation.