Maria Isabel Abreu1* and Rui Oliveira2

1 Polytechnic Institute of Bragan^a, Campus de Sta Apolonia, Apartado 1134, 5301-875 Bragan^a, Portugal
* Corresponding Author, isabreu@ipb. pt

Abstract

The use of solar energy constitutes a great concern of national and international bodies, as a result of a strategic policy towards green energy consumption. The Portuguese regulations on building thermal behaviour and energy efficiency, recently enacted by the Portuguese Government, in line with the European Union Directive 2002/91/CE, have introduced the obligatory use of solar collector technology for hot water production applied to new building projects and to some important retrofit works. To cope with the prescriptions of these regulations, the solar technology market is been growing and the Portuguese project designers and construction professionals are founding new challenges. The purpose of this study is to identify and analyse the major problems and initial impacts of the obligatory implementation of solar collector technology in buildings and provide contributions to improve solar energy use in the future. The results show that, as almost all new technology implementation, some obstacles have always to be faced initially.

Keywords: Solar Collector, Solar DWH, Building Thermal Regulations, Portugal.

1. Introduction

In residential buildings the energy for hot water production (DHW) contributes strongly to the final building consumptions of useful energy [1,2]. In the beginning of this decade, the Portuguese Program E4 — Energy Efficiency and Endogenous Energies have proposed an ambitious goal of 1 million m2 of solar collector area in Portugal until 2010. To cope with this, it was implemented in 2001 by Portuguese Government the National Program Solar Hot Water for Portugal (IP-AQSpP) [3]. A more recent government effort is The National Plan for de Energy Efficiency (PNAEE), approved some months ago, that include important measures for buildings, ambitioning an improvement of 1% per year on energy efficiency [4]. The Portuguese new Thermal Regulations (RCCTE) opens to all constructions partners a new opportunity for implementing more strongly renewable energy technologies in buildings. Using solar hot water systems it can represent a saving of 20% on the total energy consume of a family in electricity and gas [3].

2. Methodology

The methodology used on this study consisted of a literature review on government and institutions publications and information, statistics and also interviews to professionals. Secondly, to complement the analysis, it was made simulations with the regulations methodology and with the official software for solar collectors, Solterm, with the consequent discussion of results.