Measuring energy efficiency: Indicators and potentials in buildings, communities and energy systems

The research project was launched to develop a general approach to measure energy efficiency. Furthermore, the research aimed to develop an approach which could be used to calculate the potential achieved by improved energy efficiency. Measuring energy efficiency and potentials are connected strictly to each other in the sectors of energy production, industry, buildings, communities, transportation and logistics. This report is a state-of-art description and a summary of the research findings from the energy, communities and buildings sector made by VTT. Energy efficiency in energy chains was investigated in batch-surveys on the energy sector. Technical possibilities in energy chains have been evaluated for scenario calculation of energy saving potential in the future. Emissions of different energy production ways give the value for environmental impacts and further the impacts of making more effective energy chains. Energy used in communities takes place in both buildings and infrastructure, during construction, use, maintenance, repair, renovation, demolition, and recycling as well as during transportation of people and goods. Energy efficiency of communities must be a composition of energy used during the life-cycle of several physical elements brought together for the community. Energy efficiency of communities can be defined as a ratio between an input of energy consumption or emissions, and an output of services, such as number of inhabitants and jobs or floor square metres. Buildings have a high potential for energy efficiency improvements compared to other sectors of the economy. Various indicators serve different purposes and interests in the buildings sector serving from the user of the building to the regulator. Defining an universal indicator to cover all needs is not possible. Therefore an array of indicators is suggested - what indicator to use depends on the situation and the objectives of the analysis. Energy flows and embodied energy with primary energy coefficients should be included in the evaluation. Large changes in system effects should be taken in with marginal primary energy coefficient and be analyzed with e.g. scenario analysis. Economic effects should be evaluated with e.g. economic modelling. Externalities and the rebound effect should also be considered.