A Study of the Antenna Effect of Photovoltaic Modules

Abstract

We have investigated the reaction of photovoltaic

cells to external electromagnetic fields in a frequency range of

10 Hz to 1 GHz. Outdoor recordings of received RF noise from

the ambient were sampled for different solar cells and modules

and compared with the reception of a simple whip antenna

which represents a monopole for electromagnetic fields.

Additionally in the laboratory well defined signals were

generated and their reception was investigated depending on

geometrical factors of the cells, such as orientation, size and

distance. Two antenna models, namely dipole and patch

configuration, are compared with the experimental findings.

Simulations for the effect of modulated signals on solar cells

were made as well. It was found that the gain in the investigated

frequency range increases essentially linear with the cell area

similar to patch antennas. A crystalline silicon cell of 100 cm2

has almost the same signal amplification as an 83 cm long whip

antenna remaining coarsely constant over the whole frequency

range. For narrow frequency bands however the signal

attenuation or amplification is strongly modified by the dipole

behavior caused by the front metal grid. Simulation shows that

demodulation effects are biggest around the MPP, possibly

affecting subsequent power conditioning units.