Eyre (2011) notes that one of the main difficulties in reducing demand is that the percentage cost savings for the individual consumer are often less than the percentage carbon savings benefiting society as a whole. The energy efficiency of homes and businesses is in part about the interaction of technical innovations and the willingness of people to adopt them, and adapt their behaviours. For example, the innovation of automatic defrosting of freezers saves energy. This technological innovation changes social practice and aids energy efficiency by removing the need to do this manually (Shove and Southerton, 2000).
Other claims made for improving energy efficiency include: reducing energy poverty and GHG emissions, and improving thermal comfort, health, well-being, energy security, and economic productivity (POST, 2017). A useful overview of the relevant UK policy since the early 1970s is given in Mallaburn and Eyre (2014), and Hanmer and Abram (2017) stress the need to learn lessons from previous societal transitions e.g. moving from using coal to natural gas for heating homes. Most studies on DR are for buildings (Palmer and Cooper, 2014), but also of importance are industrial processes (Griffin et al., 2016, 2017, 2018) and heat (DECC, 2013a; Delta Energy & Environment, 2012; Eyre, 2011). Monahan and Powell (2011) claim that reducing heating demand will have the greatest effect on reducing GHG emissions.
A synthesis report compiled by DECC (2013b) suggests that interventions in the home may save between 1–10% depending on the sophistication of the scheme, and Rosenow et al. (2018) claim that through a combination of current technologies – including energy efficiency – a 50% saving could be made. It is estimated (LCICG, 2016a) that a total of 64 MtCO2 (by 2050) could be saved in residential buildings. A potential saving of 7% of household electricity use could be made by eliminating the stand-by mode of devices (Coleman et al., 2012). Shove (2003) contends that the population desires convenience which happens to demand energy. Recent detailed studies have shone light on household activities, practices, and the enabling products (Butler et al., 2016) which gradually become normalised (Shove and Southerton, 2000). As practices change there is a ratcheting-up of demand which acts to recalibrate societal expectations (Shove, 2003). A meta-study for DECC (RAND Europe, 2012) drew three conclusions that:
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programmes combining information feedback on comparative consumption alongside energy efficiency advice did lead to residential DR,
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awareness of pre-intervention consumption had a statistically measurable effect on the level of energy saving (independent of other factors), and
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the structure and level of personalisation of the intervention affect the level of energy saving.
The provision of information alone is insufficient (Lange et al., 2014; Busic-Sontic et al., 2017) which is described as the ‘information-involvement gap’ (Axon, 2017). Its importance is noted (Bright et al., 2018) in deep retrofit of mixed tenure tower blocks in particular. Trust has emerged as an issue in the design of programmes for DR e.g. energy advisors (Owen et al., 2014) and Government and businesses (Cotton et al., 2016). However, work on residential consumers (Volland, 2017) indicates that greater trust in institutions is associated with lower energy use and a greater tolerance to risk is associated with higher energy use, and the trust engendered by community groups is demonstrated by (Vita et al., 2020).
A group of reasons for the lack of engagement with DR can be described as cultural. Conservatism is observed amongst professionals and customers in the house-building (Heffernan et al., 2015; LCICG, 2016a), commercial building (Scrase, 2001), (LCICG, 2016b), and the industrial sectors (LCICG, 2012a). A particularly poorly understood factor is that of conspicuous consumption (Hards, 2013). Consumers may want to avoid the stigma of being labelled as “stingy”, or may prefer high-use devices such as tumble dryers to mitigate the risk of visitors being faced with an unsightly scene. The social gains of, say, a new kitchen outweigh those of energy saving measures (Dowson et al., 2012). Olaniyan and Evans (2014) suggest that for policies to tackle DR successfully they must address behavioural and lifestyle and, in addition, cultural factors (Ivanova et al., 2020).
In the policy-making process the ability to use research feedback requires robust assessment of pilot and other schemes (Boardman, 2007a; Heffernan et al., 2015), but such assessments are contextual for both consumers and policy-makers. Boardman (2004) notes that weak efficiency standards have long-term effects as devices take many years to exit the stock, and stricter regulation would be a driver to increase energy efficiency and increase market opportunities (Stiehler and Gantori, 2016). This led Gavin Killip to call for a regulatory body to draw together training, standard setting, and compliance for the house-building sector (Killip, 2013). Looking to the second half of this century there is uncertainty in the level of demand for cooling in dwellings due to climate change (Gupta et al., 2015). Both electricity and gas are used for space heating, though gas has greater market share in the UK; city-wide mapping has been conducted (Gupta and Gregg, 2018).
In their international comparison of measures and policies the IEA (2017) claim that energy efficiency has improved the economic competitiveness of energy-intensive industries, but it is worth noting that the payback period is crucial for industry (Eiholzer et al., 2017). The expected return-on-investment periods for efficiency projects in industry are short – perhaps one to two years. If the payback is quick there is no risk of lack of access to capital, but for longer than, say, three years, it will be very difficult to raise the required investment.
A principal source of energy demand is transport. Low-carbon transport cannot be realised by technology alone (Upham et al., 2013), yet policy remains focused on technology innovation and not on transport and mobility as a service. Furthermore, the widely discredited ‘predict and provide’ model persists in Government policy albeit sometimes disguised (Goulden et al., 2014). When considering innovation in transport planning to reduce energy use, Banister and Hickman (2013) recommend the use of robust scenario methods at all stages of decision making and policy planning. However, these principles are not applied universally – in the policy context, this can be considered as an example of weak technology transfer.
In their extensive review of energy system scenarios, Skea et al. (2021) note the inclusion of energy efficiency gains, however this is usually as an assumption or modelled in a superficial manner. Demand reduction is frequently overlooked in UK energy scenarios (Axon and Darton, 2022), though notable exceptions are those devised by the UK Energy Research Centre (Ekins et al., 2013; Skea et al., 2011) and National Grid (2022).