Everybody knows that solar panels convert sunlight into electricity (photovoltaic solar panels) or heat (thermal solar panels), but not everybody knows how. This conversion takes place due to the specific properties of the photovoltaic materials which make up the solar panels.
When light strikes on the photovoltaic materials of the solar panels, it occurs an internal flow of electrons. The electrons in the crystal structure of the photovoltaic materials absorb the energy of the light particles, which energises the electrons so they can move. The internal electron movement is channelled through the photovoltaic material and goes into an electric circuit, via the metal contacts on the solar panel surface. This electrical flow can then be harnessed to operate any electrical equipment.
How do photovoltaic solar panels really work?
- Grid Connect Or Stand Alone Systems
Solar panels can be connected to the grid. With this configuration, the electricity produced can either be directly injected into the grid or first it supplies the consumer’s demand, injecting only the excess electricity that was not consumed. The latter is the most common configuration, which is called self-consumption. On another hand, the system can be directly connected to a battery system through which electricity is used for the consumer’s needs with no connection to the grid – a stand alone system. Nowadays most systems are connected to the grid but the decrease of the batteries costs are encouraging more consumers to opt for the stand alone systems.
- Orientation Of The Panels
Solar panels on fixed arrays will generally be oriented towards the south in the northern hemisphere and towards the north in the southern hemisphere. This exposes the panels to the greatest amount of sun light through all the day. East facing arrays receive morning light, and west facing arrays receive afternoon light.
- Tilt Of The Panels
The tilt or angle of an array of panels must ensure that it takes in consideration the time of year that the solar panels receive the most sunlight. Arrays are positioned according to the installation site’s angle of latitude so that the panels are exposed to the greatest amount of sunlight all year round. Panels that are part of a flatter installation receive more sunlight in summer, and those on a more acute angle receive more sunlight in winter.