WHICH IS GREENER? THE GAS CONDENSER BOILER OR GROUND SOURCE HEAT PUMP. WHICH IS THE CONTRIBUTION OF RENEWABLE ENERGY TO THE ENERGY CONSUMPTION FOR HEATING TO A BUILDING?

The goals of this paper are: to estimate the carbon emission reduction on energy efficiency measurements in a laboratory building in Transilvania University from Brasov, Romania, in accordance with the European Directive 2009/28/EC and to estimate the contribution of renewable energy to energy efficiency of the building using the performance indicator named Renewable Energy Ratio -RER. We will detail the methods of calculation for CO2 emissions and we will present the results for gas condensing boiler, and ground source heat pump for the laboratory building. The results show that conventional energy efficiency technologies and renewable energy technologies can be used to decrease CO2 emissions in buildings by 20-30% on average and up to over 40% for some building types and locations. The contribution of renewable energy is between 40 and 50 % from total energy use and only for heating is 58%. This value could rise to 0.63 if we apply to electricity produced by photovoltaic panels.