A Simplified Method to Select Combined Energy Systems

A Simplified Method to Select Combined Energy Systems

Sérgio Tadeu Márcio Gonçalves Nuno Simões António Tadeu

Itecons – Institute for Research and Technological Development in Construction, Energy, Environment and Sustainability, Portugal

ADAI – LAETA, Department of Civil Engineering, FCTUC, University of Coimbra, Coimbra

Department of Civil Engineering Construction (PCC) – Escola Politécnica, University of São Paulo, Brazil

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The European Union aims to ensure that investment in energy efficiency measures is cost-effective. Thus,  the  minimum  energy  performance  requirements  of  buildings  must  follow  the  so-called cost-optimal levels. It is known that the impact of a specific measure on the energy performance is affected by others measures when implemented simultaneously, influencing its profitability. for this reason, the profitability of a given package of measures cannot result from the simple sum of potential benefits of each measure. consequently, to define a cost-optimal solution it is needed to run a great amount of combinations, implying an expensive computational effort. In order to help with the selection of the energy systems, this work proposes a simplified method for selecting heating and domestic hot water systems as a function of the following variables: initial investment, maintenance cost, energy needs and cost, and efficiency of energy systems. The proposed method is user-friendly and can assist various stakeholders: policy makers, energy experts, suppliers of products and services and building owners.


cost-optimal, energy retrofit, buildings, sustainability


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