We study the determinants of households’ choices of lighting fuels in Kenya including the option of using solar home systems (SHS). Our goal is to add new evidence on the factors that influence the introduction and adoption of decentralized and less carbon-intensive energy sources in developing countries, and, more generally, to the empirical debate on the energy ladder. We capitalize on a unique representative survey on energy use and sources from Kenya, one of the few relatively well-established SHS markets in the world. Our results reveal some very interesting patterns of the fuel transition in the context of lighting fuel choices. While we find clear evidence for a cross-sectional energy ladder, the income threshold for modern fuel use – including solar energy use – to move beyond traditional and transitional fuels is very high. Income and education turn out to be key determinants of SHS adoption, but we also find a very pronounced effect of SHS clustering, i.e. the prevalence of SHS systems in the proximity of a potential user increases the likelihood of adoption. In addition, we do not find a negative correlation between grid access and SHS use.

In order to achieve the climate protection goals in the building sector, a higher rate of building refurbishment is necessary to improve the energy standard of residential building stock in the European Union. Although subsidisation seems to be necessary, optimal measures concerning cost effectiveness are unclear. Using a stylised model of the German residential building stock, we analyse different refurbishment measures by simulating every relevant investment until 2030. In particular, we compare two different options that are relevant for political measures: first, comprehensive refurbishments that are expensive but achieve the greatest reductions in energy consumption and GHG emissions and second, partial refurbishments which include only low-cost improvements but can be achieved on a wide scale. We conclude that comprehensive refurbishments will require the least amount of investment costs per ton GHG emissions and provide the highest reductions in energy consumption in 2030. Hence, partial refurbishments are never optimal. However, in terms of cumulated GHG emissions in the period considered, the difference between both options is very small. This is due to their different dynamics: comprehensive refurbishments achieve fewer results in the first years but catch up quickly, which means that the higher the refurbishment rate the higher the advantage of comprehensive refurbishments.

Deutschland will den Energieverbrauch sowie die Treibhausgasemissionen senken. Nach Industrie, Gewerbe und Verkehr rückt dabei auch immer mehr die Wärmeversorgung von Wohngebäuden in den Fokus. Das HWWI hat zusammen mit Shell die erste „Shell Hauswärme-Studie“ erstellt. Darin werden verschiedene Szenarien zu Energieverbrauch und Treibhausgasemissionen der Zukunft entwickelt.