T h e E x p e r i m e n t a l P e r f o r m a n c e
687
THE EXPERIMENTAL PERFORMANCE OF THE WATER TYPE
PV/THERMAL COLLECTOR ACCORDING TO HEAT ABSORBERS
Jeong, Seon-Ok
1
& Kim, Jin-Hee
2
& Kim, Jun-Tae
3
1
Graduate School, Department of Architectural Engineering, Kongju National University, 275 Budae-Dong,
Cheonan, Chungnam 330-717, South Korea
2
Research Professor, Green Home Technology Research Center, Kongju National University, 275 Budae-
Dong, Cheonan, Chungnam 330-717, South Korea
3
Professor, Department of Architectural Engineering, Kongju National University, 275 Budae-Dong,
Cheonan, Chungnam 330-717, South Korea
Abstract
A water type photovoltaic-thermal (PVT) module is a device that combines a PV module
and a solar collector to generate both electricity and heat simultaneously. The heat from
PV modules can be removed to enhance the electrical performance of PV modules and
converted into useful thermal energy. In many studies various water type PVT collectors
have been proposed in an effort to increase their electrical and thermal efficiency: glazed
and unglazed collectors, flat plate collectors, concentrated collectors and so on. The
thermal and electricity performance of water type PVT collectors is influenced not only to
the collector design such as the existence of glass cover, but also to absorber designs
such as sheet-and-tube and fully wetted. For flat plate PVT collectors, the design of
absorber to contact with PV modules and water tube is regarded important as it is
related to heat transfer from PV modules to water on the tubes. The aim of this study is
to analyze the electrical and thermal performance of unglazed water type PVT collectors
with rectangular tubes attached to plate absorbers. The experimental performance of two
different types of PVT collector according to the number of water tubes was compared.
In addition, the electrical performance of a conventional PV module that was used in the
tested the PVT collectors was compared to that of the PVT module.
Keywords:
PVT combined module, water type PVT, thermal efficiency, Electrical
efficiency, rectangular tube absorber,
Introduction
A water-type photovoltaic-thermal (PVT) module is a device that combines a PV module
and a solar collector to generate both electricity and heat simultaneously. Furthermore,
enhance the PV efficiency through a cooling effect. This can be achieved by circulating
a relatively cold fluid, water on the underside of the PV module.
Over the past few years, a lot of research has been performed on various design
possibilities for water-type PVT systems in order to improve their performance (Huang
2001: 443-448, Chow 2006: 300-301). Prior research mainly focused on investigating the
difference in performance based on the existence of glass covers (Kim 2009:792-797).
In addition, some other studies dealt with various absorber designs (Zondag 2003: 255,
Chun 2011:93-98).
PVT modules can have varying levels of thermal and electrical performance based on
the design of an absorber that transmits solar radiant heat. Water-type PVT modules can
be divided into a sheet-and-tube type and a fully-wetted type depending on the absorber
design (Zondag 2003:255). In the case of the sheet-and-tube type, the type of the tube
contacting sheet is generally circular. However, a rectangular-shaped tube is sometimes
applied as well. In Korea, studies on PVT modules equipped with circular-tube absorbers
were mainly carried out. Of these studies, most of them focused on whether glass was
used or not (Kim 2008:184-189, Kim 2008:260-265, Kim 2009:37-42, Kang 2009:780-
785, Chun 2010:21-26). More recently, a study that examined the thermal and electrical
