Solar panels are becoming increasingly popular. Whether it’s to promote renewable energies or to keep energy costs under control, more and more of us are producing our own electricity. Photovoltaic panels or solar panels can meet a wide range of needs. These needs can be for both private individuals and professionals. Installing a solar panel or photovoltaic panel can be quick and discreet. The impact of this installation on a bill can be immediate. But before you start generating your own solar energy, there are a few basics to keep in mind. How do solar panels work? How can the sun’s heat be converted into electricity? What are the main components of a photovoltaic panel? What is the expected yield of an average solar panel? Can solar panels be installed in less sunny regions? Let’s take a look at these questions.

How do solar panels generate electricity?

How does a solar panel work? Solar panels and solar energy: definition and operation.

 When we talk about a solar power system, we mean a three-part system: one or more solar panels, an inverter and a meter.

 What is a solar panel?

Solar panels: a solar panel is a device that uses sunlight to convert it into electrical energy, known as a photovoltaic solar panel;

Solar thermal panels

A solar panel can also use sunlight to convert it into heat, to power a water heater for example, in this case a solar thermal panel.

It is also possible to combine these two technologies for certain installations.

 Photovoltaic solar panels

Solar panels capture sunlight and convert it into direct electrical current. When a system includes several solar panels, they are installed in a row and connected to each other, to work together with the rest of the photovoltaic system, which includes the inverter and the meter. 

The role of the inverter and the meter: the inverter or solar inverter.

Once the solar panel has captured the sunlight and converted it into direct current, the inverter comes into play. The inverter transforms this direct current into an alternating current. The inverter’s main purpose is to make it easier to transport the energy produced, especially over the medium-voltage lines of the power grid. Electricity can then be transmitted to buildings and homes.

 The inverter is a metal box fitted with a heat sink and a fan. The inverter is generally installed as close as possible to the solar panels to limit electricity losses. Generally speaking, the inverter manages all the solar panels in your photovoltaic system. However, it is also possible to use micro-inverters that are specific to each solar panel. These solutions are ideal for smaller installations. They also prevent the whole system from failing if just one solar panel malfunctions.

 Each photovoltaic panel installation has two types of meter:

           -a production meter: this measures the amount of current injected into the grid. It also measures the amount of current consumed from the grid.

           -a “non-consumption” meter if you sell all the electricity you produce. This meter records the energy fed into the grid. In particular, it checks that your photovoltaic system is not consuming electricity.

How does a solar panel battery work? Why store solar energy?

By definition, photovoltaic electricity production is linked to sunlight. So it’s during the day that the installation of photovoltaic panels will produce the most energy. However, this is not necessarily when electricity is consumed. As a result, there is often a time lag between when electricity is produced and when it is consumed. To compensate for this time lag, batteries can be installed with photovoltaic panel installations, to use the electricity produced by the solar panels when required.

The solar battery is usually located between the solar panel and the inverter. In this case, it stores direct current and discharges into the inverter as needed to produce alternating current.

 We recommend that you check the following points when selecting batteries:

• its service life, often estimated in cycles, i.e. the number of charges and discharges
• its storage capacity, estimated in Watt-hours (Wh) or Ampere-hours (Ah) ;
• Discharge rate, to find out how quickly the battery will discharge.

The installation itself: some battery technologies are particularly well suited to certain solar panel installations. AC batteries, for example, are compatible with microinverters;

energy requirements: if daily electricity consumption is low, you won’t necessarily need a high-performance battery.

What is a photovoltaic cell and how does it work?

 How does a photovoltaic cell work? 

We’ve just seen how a photovoltaic panel system works overall, but we still haven’t answered one basic question: how do you generate electricity from sunlight? The heart of this mechanism is the photovoltaic cell.

How a photovoltaic cell works: sunlight emits packets of energy called photons; when the light hits a cell, these photons collide with a semiconductor material called silicon; this shock “excites” the electrons, which move within the metallic conductor.

This metallic conductor only allows electrons to move in one direction. However, the electrons have to get back to where they belong: to do this, they have to travel via an external circuit. It’s this movement via an external circuit that produces a direct electric current, which the inverter will later transform into an alternating current.

What is the efficiency of a solar panel?

 How do I calculate the efficiency of a solar panel?

When we talk about yield, we’re talking about the actual amount of electricity produced by the system in relation to the solar energy received by the panels. The yield of a solar installation is therefore based on several criteria:

First of all, solar radiation: the more sunlight the solar panel installation receives, the more electricity it can generate. 

This element can also be conditioned by several variables: the amount of sun your installation receives, particularly in relation to its exposure; shadows and obstacles (trees, neighboring buildings, etc.) that can hide the installation; orientation and inclination in the case of roof-mounted solar panels.

Even if there’s little sunshine, the system will still produce electricity. A greater amount will be produced in good weather, as one of the major factors is light intensity. So you don’t have to live in a “hot” region to generate your own electricity.

 Solar panel manufacturers give an indicative yield. It is estimated as a percentage. An efficiency of indicates that the panel will be able to convert  of the energy received into electricity, when conditions are optimal. 

How to improve the efficiency of a solar panel

Finally, all the components of a photovoltaic system can have an impact on yield, as they can cause power losses. This is the case, for example, depending on the nature of the cabling, the quality of the inverter and the layout of the equipment