Assessing the extent of evidence available relating to the impact of solar energy for households (HHs) in developing countries, surveys are reviewed focusing on the impact of pico‐photovoltaic (e.g., solar lanterns) or solar home systems (SHS) on rural HHs and directly related economic activities of their occupiers. Ninety‐eight documents have been analyzed. Areas of enquiry have included the impact of small individual solar photovoltaic systems on different facets of the life of HHs' occupiers: their education, health, finance, livelihoods, and social relations.

Many recent major studies, including the IPCC’s Fourth Assessment Report, have attested that energy efficiency is humanity’s prime option to combat climate change in the short- to mid-term. The potential to avoid CO2 emissions cost-effectively has been reported to be significant through efficiency policies. However, the review of global research findings on the quantification of cost-effectiveness of opportunities through improved efficiency has highlighted that there is a major shortcoming in the vast majority of such calculations.

Co-benefits rarely enter quantitative decision-support frameworks, often because the methodologies for their integration are lacking or not known. This review fills in this gap by providing comprehensive methodological guidance on the quantification of co-impacts and their integration into climate-related decision making based on the literature. The article first clarifies the confusion in the literature about related terms and makes a proposal for a more consistent terminological framework, then emphasizes the importance of working in a multiple-objective–multiple-impact framework.