Brazilian Solar Water Heating Systems Evaluation

E. M. D. Pereira[16]*, A. S. de Andrade1, E. M. Duarte1, L. P. Carvalho1, C. V. T. Cabral1, L.
E. M. de Vasconcellos[17]*, E. Salvador2, G. C. dos Santos2, J. T. V. Pereira[18]*, J. T. Fantinelli3,

J. T. Pallottino[19]* and N. C. Guimaraes4

1GREEN — Grupo de Estudos em Energia — PUC-MG, Belo Horizonte, Brasil
2Eletrobras — Centrais Eletricas Brasileiras — Departamento de Desenvolvimento de Eficiencia Energetica
3NIPE — Universidade Estadual de Campinas, Brasil
4CEFEN — Universidade Estadual do Rio de Janeiro, Brasil
*E. M. Pereira, green@pucminas. br
*L. E. M. de Vasconcellos, menandro@eletrobras. com

Abstract

ELETROBRAS1 and GREEN2/PUC-MG3 are developing a project integrating actions with PROCEL4, to evaluate what is the real situation of the solar water heating systems in Brazil in the residential, service and industrial sectors. Therefore, 7 Brazilian cities were selected to be studied, then information will be collected and statistically treated leading to later field research. At that stage, the collected information are the real design conditions, installation, operation and life cycle of the systems and users’ satisfaction level. Technical questionnaires were developed to summarize all the required information, such as a website, designed to organize and manage the collected data, and a Matlab application that perform the dimensioning and F-chart systems evaluation. Quality indicators are being created through a full system monitoring, with thermographic analysis and evaluation of shading influence at the system’s efficiency, using the Ecotect software. Until now, more than 274 installations were visited of 800 intended to be studied. This article presents some results observed at 3 cities: Belo Horizonte, Campinas and Rio de Janeiro. This project, nationwide, is unprecedented and will get a list of recommendations geared to formulate a development plan for the sector, which could be used as a guideline for government policies.

Key words: Solar water heating, quality indicators for solar water heating systems, products quality, shading analysis.

Introduction

In 1997, Brazil had created a quality certification program for solar collectors and thermal storage tanks, coordinated by the National Metrology Standardization and Industrial Quality Institute (INMETRO) and ELETROBRAS/PROCEL, counting on the support of Energy Studies Group GREEN/PUC-MG and the Technology Research Institute of Sao Paulo/IPT. Currently,

85 active companies have joined this program, testing in this period 316 models of solar collectors and 281 of thermal storage tanks, presenting nowadays 22% of assays demand annual growth. Solar collectors total area installed in the country is 3,6 millions of square meters, expressing an insertion factor of only 19,2 m2/1000 inhabitants.

In order to create government policies to incentive the usage of solar heating, it is needed to evaluate the real impact of this technology into the national energy matrix with Demand

Management actions, through an estimation of final energy savings and the periods of higher energy demand peak displacement. These are important factors in a country where electric heaters devices participate at about 73% of households’ hot water production for sanitary usage. In the South and Southeast regions, this number reaches 98,6% and 91,1%, respectively [1].

However, the energy production of a solar system depends not only on the component’s quality and thermal performance, but also on their correct insertion in building, appropriated project’s design and quality, besides correct installation and maintenance executions. Therefore, an evaluation of in situ solar water heating systems program has been created in October 2006 in Brazil. The main goal of the finished research, which belongs to this actions program PROCEL integrated, was to characterize and evaluate solar water heating systems in 3 Brazilian cities: Belo Horizonte, Campinas and Rio de Janeiro. These 3 Southeast cities were chosen, among others, because they represent the major penetration of solar water heating in small, medium and large size systems applications in the residential sector, with inherent particularities of usage in different economic groups of population. In Rio de Janeiro, the low income households studied in this project were contemplated with solar water heating, whose all project stages, acquisition and installation were responsibility of the local energy distribution company — LIGHT RIO.

The high income households’ studies were performed at Campinas and Belo Horizonte, in the last of which buildings with central solar water heating were studied.

This project aims the definition of incentive plans to the users and suppliers of solar water heating, training programs to the production and installation companies and designers, the creation of quality marks, besides a statistic filtering about the current overview of this type of system in Brazil.