Solar panels cannot be connected directly to the battery, they must be connected through a solar regulator.
3.1. Solar regulator
This is responsible for adjusting the voltage to that of the battery (36 or 48 Volts for example) and modifying the current (Amps) according to the amount of light energy supplied by the sun.
The most common type among solar cyclists is the MPPT “boost” technology regulator.
The regulator’s MPPT technology ensures the best possible efficiency in the conversion of electrical energy. The qualification “boost” means that the voltage of the panels at the input of the regulator must be lower than that of the battery and the regulator then adjusts the output voltage to that of the battery.
3.2. Solar panels
The preferred panels are flexible monocrystalline silicon panels: they are light and have a good conversion efficiency of light energy into electrical energy. Better to forget the models developed for the roofs of houses, in polycrystalline silicon (very heavy, lower performance).
The solar bike builder will have to choose the format of his panels according to his bike and the structure planned to support them.
To participate in the Sun Trip, the width of the panels must not exceed 1 meter which corresponds to 7 photovoltaic cells (in the costing dimensions of 12.5cm x 12.5cm). But the traditional formats have rather even numbers of cells, in practice, a majority of solar cyclists now have panels of 6 cells in width.
|2 cells =28cm||4 cells =54cm||6 cells =80cm|
The length of the panels will depend on the bike chosen, or the trailer …
Warning: the size of the panel has a direct influence on its electrical characteristics, it is advisable to ensure the adequacy between panels, regulators and battery.
The quality of a panel, in terms of electricity production, depends a lot on the quality of the photovoltaic cells that constitute it. In the technical sheet, the mention of a major cell manufacturer is a guarantee of quality.
However, the big manufacturers sort their cells and sell them in different quality grades. But this clue is never mentioned by the panel manufacturer.
3.3. Support structure for solar panels
How to transport solar panels on a bicycle? This is one of the important questions that the solar cyclist asks himself. This question is also related to the surface of panels that one wishes to install.
If installing 1 panel of 0.7 m² is quite simple, installing 2.5 m² of panels is much more complicated.