The energy injustice of household solar energy: A systematic review of distributional disparities in residential rooftop solar adoption

Power generation from grid-connected residential photovoltaic (PV) systems has been widely recognized worldwide as an integral component in the energy transition. However, concerns remain about whether its costs and benefits have been fairly distributed in our society. This systematic review was conducted using 87 articles to explore inequalities in the adoption of rooftop PV systems in the world and its distributive impacts. There is strong evidence that adoption occurs predominantly among affluent households, and although some studies show a reduction in concentration over time, adoption remains uneven in most places. Furthermore, the incentive policies for rooftop PV have regressive characteristics, as they especially benefit the wealthiest, while their costs disproportionately affect the most vulnerable households. To address this situation, the literature recommends targeting subsidies to lower-income households, encouraging community solar facilities, and better publicizing the characteristics of the incentive programs, especially in vulnerable communities. In addition, using more cost-reflective electricity tariffs and replacing the feed-in tariff mechanism with market-oriented policies can help reduce inequalities. Finally, the article outlines future research agendas to expand upon the insights gained from this study.