What are the main components of a photovoltaic system, and what are their functions?
The mounting system is the framework to which the panels mount. It is of great importance to the total cost, the speed of construction, and even the longevity of the photovoltaic installation. The optimal choice of mounting system depends on the location of the panels, as well as their number and orientation.
The photovoltaic panels convert light to electricity via the photovoltaic process. Solar panels vary in terms of the technologies they employ, their performance, physical size and price. It might be tempting to think that only the highest power panels are worth considering, but smaller and lower output panels can be better suited for some installations.
Every solar panel has a negative and positive lead connected to it, allowing them to be daisy-chained together into strings of multiple panels each.
Solar cables are an often overlooked component. However, depending on the size of the PV installation, their total length can be several kilometres long. These cables have reinforced outer insulation, usually made from two layers. Typically they have a 4-8mm2 cross section and carry up to 1 kV.
Inverters are electrical devices that convert the DC power generated by the panels into AC power. There are different types of inverters, including string inverters, microinverters, hybrid inverters etc. Some can connect to the solar panels directly, while others need an MPPT solar controller. For example, hybrid inverters can charge batteries while sting and micro inverters cannot.
Batteries for local storage are becoming more popular as prices have come down. These batteries can store the excess power produced during the day, allowing users to increase their self-consumption share. The batteries require a solar charge controller or a hybrid inverter to manage them.
The solar charge controller sits between the battery and solar panels and actively manages the power output. Modern MPPT charge controllers use clever algorithms to continuously monitor the I-V curve and extract the most power out of every string of panels.
System monitoring and control functions are a feature of every modern photovoltaic system, and some high-end inverters even have this functionality built-in. Typically we use a dedicated device such as the Victron Cerbo GX, which works great and offers excellent compatibility with third-party devices. Users can configure, control and monitor their photovoltaic system locally or remotely over the Internet.