40% CO2 saving target in the German building stock up to 2020 – integrated assessment scenarios with the Built-Environment-Analysis-Model BEAM²

Panel: 5. Saving energy in buildings: The time to act is now

This is a peer-reviewed paper.

Author:
Kjell Bettgenhäuser, Ecofys, a Navigant Company, Germany

Abstract

Germany wants to bring down CO2-emissions by 40% across all sectors by 2020 vs. 1990. Setting the 40% target for the building sector (which equals 90 Mt), the aim of the project is to determine whether the current measures in place are sufficient to reach climate targets in 2020. Therefore a reference scenario has been set up, which quantifies the final energy demand and emissions for heating demand, hot water and building related electricity consumptions from 1990 to 2010 for the German building stock in an ex-post literature research. For the period 2010-2020, a forecast has been developed by use of the Ecofys Built Environment Analysis Model (BEAM²). Based on a set of input parameters like floor areas, reference buildings, insulation qualities and energy supply systems, the BEAM² model was used for creating a consistent set of data including energy consumption, CO2-emissions, running costs and investment costs of energy efficiency measures and energy supply systems of buildings. Generally the model has been developed for scenario developments, showing the potential effects of certain energy saving packages distinguished by country, climate zone, building type, size and vintage, as well as insulation level, energy carrier and energy costs.

Main result of the model calculations is the reference scenario’s carbon reduction of 38% in the building sector. Thus most probably 40% target will be missed slightly, assuming the framework given at January 1st 2010 being unchanged till 2020 and a retrofit rate of 1.4%. A retrofit rate of only 1.0% till 2020 will result in a gap of approximately 9.5 Mt CO2 in 2020 for emissions from heating and hot water in the residential and non-residential building sector (excluding industry buildings), being equivalent to 35% carbon reduction.