(91b) Numerical Simulations and Experiments on a Photovoltaic Solar Wall

1. Numerical Simulations A two dimensional thermal network model is proposed to predict the temperature distribution in the photovoltaic solar wall section of an outdoor test room facility at Concordia University, Montréal, Québec, Canada. Steady-state thermal network nodal equations are developed for a photovoltaic solar wall section by neglecting thermal storage in double-glass photovoltaic module and well-insulated back panel. The enclosure analysis is assumed for obtaining radiative conductances to ascertain the effect of radiative heat exchange in between the distant composite surface nodes. One dimensional solution obtained from the heat balance model eliminates the non-linear variation of temperature dependent boundary conditions applied to thermal network. The proposed model was able to predict the temperature distribution in the test section for a range of measured climatic data under the strong influence of conjugate heat exchange.

2. Experiments The preliminary field experiments were conducted on ascertaining electrical and thermal characteristics of a pair of glass coated photovoltaic (PV) modules. Both indoor and outdoor experiments were conducted on glass coated PV modules. A pre-fabricated outdoor room was also used for conducting some of the outdoor experiments on glass coated PV modules installed on a wooden frame. The experiments on obtaining electrical characteristics of PV modules included were indoor solar simulator tests conducted under standard operating conditions, outdoor tests conducted with and without a wooden frame under available climatic conditions. Both indoor and outdoor experiments were conducted for obtaining current-voltage and current-power characteristics for a pair of PV modules. The current-voltage measurements were also obtained for determining electric power output with a series electrical circuit connection of a pair of vertically inclined PV modules installed on a wooden frame. The experiments on determining thermal characteristics included were outdoor tests conducted for obtaining temperatures, air mass velocities, sensible heat, thermal storage and thermal time constants of PV modules with and without wooden frame. After conducting a series of field experiments, preliminary results have concluded that: i) glass coated PV module installed on a wooden frame has more heat generating capacity in comparison to a window glass or a stand alone PV module; ii) the generation of electric power is affected with operation of vertically inclined PV modules; and iii) electrical and thermal characteristics are function of both ambient air temperature and thermal storage losses.