Knowing the components of a photovoltaic installation is key to optimizing the cost of the installation and optimizing its future performance.
Although there are an infinite number of different configurations to carry out a solar photovoltaic installation, there are several elements common to all of them. These elements are indispensable, since the lack of any of them would prevent the generation of electric energy. We are going to detail them one by one.
Photovoltaic panels
Photovoltaic panels are the most visible part of any installation. They are where the photovoltaic effect takes place, where a potential difference is generated that produces the direct electric current. The panels are usually connected in series, forming strings. With this connection between the panels, the voltages of each one can be added, reaching the values required for the correct operation of the inverter.
Inverter
As its name indicates, the inverter is the device in charge of transforming (inverting) the direct current coming from the photovoltaic panels into alternating current, which is necessary for the operation of all the loads of the installation.
The inverter has a measuring element, which allows knowing the state of the grid and thus adjusting its output voltage, or limiting its generation in the case of zero injection installations. Inverters usually have an internet connection for remote control and monitoring.
Support structure
To fix the photovoltaic panels it is necessary to use an auxiliary structure that serves as a support. Normally this structure is metallic and its shape and size will depend to a great extent on the surface and location of the photovoltaic panels where the installation is to be carried out.
The most common structures are usually of two types:
- Coplanar (in case of roofs with good slope and orientation)
- Triangular with different inclination, depending on the latitude.
There are also large pergola-type steel support structures or solar trackers (single or dual axis) that maximize the performance of photovoltaic solar panels.
Control and protection devices
This component of the photovoltaic installation encompasses the set of existing electrical protections aimed at protecting both the power generation components and the users.
According to the REBT (Low Voltage Electrotechnical Regulations), it is mandatory that each inverter be accompanied by two circuit breakers:
- A differential (to protect in case of electrical shunts)
- A circuit breaker (which protects against permanent or transient power surges, and also serves as a cut-off device).
In addition to these two circuit breakers and depending on the requirements of each installation, other devices such as fuses or surge protection can be installed.
Electrical conductors
Once the direct current has been generated and transformed into alternating current, we need to conduct electricity from one point to another.
In the electrical conductors used between the panels and the inverter, a red wire (positive pole) and a black wire (negative pole) are used. Normally these cables have cross-sections of 4 to 6 mm2.
We must also have a green and yellow grounding wire.
These five elements are the components of an electrical installation that we will need at least to carry out the installation, but we can find some more components.
For example, when several inverters are used in the same installation, it is often necessary to use an additional device to monitor the intercommunication between the inverters.
It is also common to install batteries to store occasional production surpluses and thus adapt their consumption to our needs.
Another element used in photovoltaic panel installations is the backup, which allows the inverter to operate even if there is a power failure in the grid.
Sometimes it is advisable to complement the installation with an alternative generator (usually diesel or wind), which allows to generate electricity in case of low sunlight or in the event of a peak load.
These are the components of a photovoltaic installation, as we can see there are not many, but the optimization of the energy produced and the profitability of the investment made will depend on their correct installation.