4.3.1.2 Fast growth in renewable electricity supply drives social tipping in the energy system

Cost reductions in renewable generation technologies like wind energy and solar photovoltaics (PV) have been much faster than predicted. Renewables are now among the cheapest electricity generation options (Haegel et al., 2019; IRENA, 2022a; IRENA, 2022b). For wind and solar energy generation, the main reinforcing feedbacks that created these tipping dynamics are cost reduction and performance improvements through investment in research and development, learning-by-doing and economies of scale, leading to more deployment and, in turn, to more learning and price reduction (Sharpe and Lenton, 2022; Kavlak et al., 2018, Nemet and Greene, 2022).

The German feed-in tariff for renewables discussed in 4.2.1 was historically an enabling condition for a positive tipping point in the solar PV sector (Otto et al., 2020; Clark et al., 2021). Moreover, markets are still expanding as performance improvements make the technology attractive to a wider range of users. As a result of these technological improvements and cost reductions, renewable generation is increasingly possible in locations where wind or sun conditions are less favourable. The exponential growth of offshore wind power in the North Sea (Drummond et al., 2021; Geels and Ayoub, 2023) and the increasing attention for floating solar (Karimirad et al., 2021; Pouran et al., 2022) illustrates this. Renewable energy generation coupled with battery storage is expected to reach cost parity compared to power generation from natural gas in the near future, if it has not done so already (Meldrum et al., 2023), as battery costs are driven down by the growing electric vehicle industry, further enhancing the competitiveness of renewables with fossil fuels. 

The cost-performance feedback loop is the main, but not the only, feedback driving the tipping dynamics for wind and solar. For instance, there is evidence for social contagion in the diffusion of rooftop solar PV, which is typically clustered in space where people are more likely to adopt when people nearby also have adopted (Graziano and Gillingham, 2015; van der Kam et al., 2018). This suggests that their diffusion is partly a social process influenced by, for example, observability, trialability, and word-of-mouth (Rogers, 2003) and social comparison (Bergquist et al., 2023).

Another reinforcing feedback loop stems from policy interactions, whereby policy creates legitimacy and new interests, leading to increased lobbying and support for policy (Roberts et al., 2018; Meckling, 2019; Rosenbloom et al., 2019; Sewerin et al., 2020). Further, strong pro-environment policies may incentivise firms towards more RandD and innovation, thereby expanding industrial sectors for low-carbon technologies. In this way, public opinion may also increase support and acceptance for new low-carbon technologies, increasing pressure on policymakers in creating goals and strategies for a more sustainable society (Geels and Ayoub, 2023).

Sources of dampening feedbacks, lock-in and path-dependence of fossil fuel-based energy systems include energy infrastructures, technologies and institutions (Köhler et al., 2019). These can directly hinder the decarbonisation of the energy system through existing standards and resistance from incumbents and vested interests. Indirectly, the availability of cheap energy has stimulated demand for energy-intensive goods and services. Similarly, the high return on fossil fuel investments and the assessment of renewables as risky require policy attention to stimulate the move of capital from fossil to renewables (Pauw et al, 2022, see also 4.4.4). As an example, in the early 2000s, the UK government provided initial capital grants to boost offshore wind demonstration projects, resulting in a game changer into the overall offshore sector. This has, in turn, built confidence among financial investors, easing access to resources for project developers (i.e. lower interest rates) (Kern et al,. 2014; Geels and Ayoub, 2023). 

Social dynamics can lead to reinforcing feedbacks but may also create dampening feedbacks when they mobilise opposition and a lack of societal support for larger-scale solar and onshore wind farms (Devine-Wright, 2007; Klok et al., 2023; Windemer, 2023). Cost-competitiveness is not a sufficient indicator to predict support for technologies for which the main public concerns are about spatial/visual impacts, health and safety, and questions of fairness. 

Policy for positive social tipping can seek to strengthen reinforcing feedbacks and reduce dampening feedbacks. The policy-relevant timescales of the energy system vary from months to decades. Energy infrastructures are typically built for a lifespan of around 40 years, and changing these infrastructures takes place on the timescale of months to years. Once built, they contribute to stabilising the system state and are a source of path dependence and lock-in. In contrast, some demand-side behaviour changes are quite swift. An example is the substantial energy demand reduction in Europe in the winter 2022/2023, resulting from concerns about high energy prices and the war in Ukraine. A key policy challenge is how to make the new behaviour ‘stick’.