Assessment of residential wood energy consumption using German household-level data
The residential sector accounts for about half of annual wood energy consumption in Germany. We applied a left-censored Tobit model to a cross-sectional dataset to quantify factors affecting household-level German residential wood energy consumption in years 2005, 2010 and 2014. Explanatory variables distinguished between (1) heating technology, dwelling characteristics and alternative energies; (2) woody biomass accessibility and weather; as well as (3) households' socio demographic characteristics. Results show that wood energy consuming households with central heaters used an additional 0.83–1.82 m³ year−1 of wood. Households' wood energy consumption showed a positive correlation with residence area and elastic responses to year of building construction. Greater elasticities in wood energy consumption were found when alternative energy prices exceeded US$ 1,050-1,330 per ton of oil-equivalent net calorific value. Local accessibility of woody biomass measured through forest ownership and forest density was associated with greater wood for energy consumption by an average 0.27–0.52m3 year−1 and 0.13–0.25m3 year−1, respectively. In addition, wood energy consumption increased proportionally with increasing rurality. Elasticity of household wood energy consumption with respect to heating degree days was estimated at 0.83–1.15. Among demographic variables, households at lower and higher income levels exhibited greater amounts of wood energy consumption. Results provide evidence that greater adoption of central wood energy heaters, price competitiveness of wood energy over alternative energies, and improving access to wood energy sources can lead to greater residential wood energy consumption in Germany.