Understanding the basics of electricity and photovoltaic

What is the difference between Volts and Amps? Kilowatts and kilowatt-hours?  What is the purpose of an inverter and a regulator? What is inside a generator?

If you are asking yourself these questions and don’t have all the answers, then this article is made for you. We will try to simplify and explain most of the elements used in a solar photovoltaic system. Much like this article, O’Sol’s solar generators are made to be user-friendly and simple to use!

 

The basics of electricity explained with water

To understand the fundamentals of electricity, it is important to understand and visualize its main parameters such as tension, intensity, resistance, power and capacity.

An analogy with water will help you understand them. In a given volume of water, there is a given number of water molecules, the elementary blocks that make up the liquid. Electrons can be compared with these molecules, as they also represent the equivalent elementary blocks in electricity. It is the movement water molecules that creates a flow of water, much like the movement of electrons creates electricity. Generating electricity therefore revolves around making the electrons move.  

Let’s now picture a water mill, built on a river at the bottom of a snowy mountain.

 

The main components of a photovoltaic generator

A solar photovoltaic system made up of several components, each of which play a precise role. The ultimate objective is to convert the energy from the Sun into electricity, with a controlled tension, intensity and signal shape.

Let’s start with the key component of a photovoltaic system: the solar panel. A photovoltaic panel is made of numerous cells that enable a fundamental principle: the creation of a tension, and therefore the “presence of electricity”. In a nutshell, when the incoming rays of sunlight, charged with energy, collide with the cell, it creates a tension between one end of the cell and the other which forces the electrons to move. This is why it is more efficient to position the solar panel so that it is perpendicular to the solar rays: the “collision” creates more energy. Let’s bring back the previous analogy: the snowy mountain is itself the cell. The warmer it gets, the more snow melts and the more water flows downstream. The current generated in a photovoltaic system is proportional to the light flow received by all the cells (in other words, the sunnier it gets, the more electricity is generated) and this current takes the shape of direct current (commonly referred to as DC).

O'Sol solar generator

The electricity generated by a solar panel can be used directly, but since its electric current is highly variable (clouds, shadows…etc), it is often necessary to regulate it with the use of a battery. The battery is nothing else but a reservoir which stores electric energy until needed.

It is important to regulate the inputs and outputs of that reservoir (not filling it either too much or too fast and not emptying it too much nor too fast) to avoid damaging it. That is the role of a regulator. This component links the panels, the batteries and the power output (energy consumption). It allows an optimal combination between the direct energy coming from the solar panels and the energy stored within the batteries.  

The electrical current can take the shape of a direct current (DC) or of an alternative current (AC). Besides the fact that electrical devices need a specific tension and intensity, they often need an electrical input in the form of alternative current. The inverter is the component that turns direct current, coming from the solar panels and batteries, into alternative current that can be used by most electrical devices.

 

In a nutshell, one can refer to this hydraulic analogy to understand the abstract principles that lie behind electricity, and in particular those of photovoltaic energy. As said by Einstein, the things you master can be explained in a simple way. At O’Sol, we master solar energy for you, and count on the simplicity and efficiency of our solar solutions. Our service and products will convince you, so do not hesitate to get in touch with us!