Impact of appliances and lighting for Nearly Zero Energy Buildings (nZEBs) in Europe

As established by the recast of the European Union (EU) Directive on Energy Performance of Buildings (EPBD), all new buildings should be nearly zero energy buildings (nZEBs) within the EU by the end of 2020. However, reaching this result at the lowest possible cost remains an important challenge. Balancing renewable power generation with energy efficiency will be vital in Europe. We describe results obtained from the use of energy optimization software BEopt developed at the U.S. National Renewable Energy Laboratory. The model performs detailed hourly sequential simulations using the energy performance software EnergyPlus showing how to best achieve very low or zero energy home designs at the lowest possible cost in 36 representative locations across Europe. We have adapted the model to run using European hourly climatic data, using relevant construction methods, cost data and unit energy consumption. A novel aspect is the inclusion of the likelihood of future climate change relative to cooling loads estimated. This anticipates building design changes necessary to address the challenges to be faced in a changing world. A key finding of the research is that energy reductions of 80% and beyond are economically feasible for new construction, although the mix of selected measures varies strongly with climate. Results show that a broad approach to efficiency mixed with renewables performs best, while a narrow focus on building thermal performance can be counterproductive. In particular, we illustrate how exclusion of lighting and appliances results in sub-optimal solutions, especially for electricity use which has a disproportionate impact on greenhouse gas emissions.JRC.F.7-Renewables and Energy Efficienc