Solar energy - an inexhaustible and ecological resource on earth

Solar energy is an inexhaustible resource, one of the cleanest sources of energy and therefore environmentally friendly. On our planet, we have an enormous amount of solar energy obtained from the sun. We can put this solar energy to good use. 

Photovoltaics - what it is and how it works  

the sun shining on the roofs of houses

Photovoltaics is the field of science that deals with the conversion of sunlight into electricity, i.e. the generation of electricity from the sun's rays. This is made possible through the use of various technologies, most notably photovoltaics. This conversion of light into electricity takes place in so-called photovoltaic cells. This is an environmentally friendly source of renewable energy.  

Photovoltaic cells are manufactured from a semiconductor material (it is usually silicon) and by joining together they form a photovoltaic module. This module is housed in an aluminium or steel frame to protect the cells from mechanical damage. In these cells, the photovoltaic phenomenon takes place - the conversion of energy from the sun into direct current. This current then runs to a device called an inverter (inverter). Here, the direct current is converted into alternating current (i.e. the kind we have in our household sockets).  

The photovoltaic installation includes:  

  • Photovoltaic panels (called solar) - convert energy from the sun into electricity. 

They can be monocrystalline or polycrystalline. They differ in colour, structure and efficiency. Monocrystalline panels have a black colour, while polycrystalline panels are blue. Monocrystalline have a higher efficiency and power output than polycrystalline.  

There are also CIGS cell panels (which work well on building façades) and CdTe cell panels (which have a distinctive red colour and are made of a single cell). 

  • Inverter - converts direct current into alternating current. 

It is known as the heart of the installation. It regulates the operation of the PV system. Its task is also to provide protection during a fault, during a power failure in the grid. In this case, it disconnects the PV system and interrupts energy distribution. The inverter can be mounted externally or internally. There are 3 types of inverters: central inverters, micro inverters and string inverters. 

roof fitter for photovoltaic panels
  • Mounting system - allows panels to be mounted on a variety of roof types and surfaces. 

It is most often made of stainless steel and/or aluminium, due to the fact that these materials are rust-resistant.  

  • Wiring - cables connecting the installations to the internal network. 

Specialised accessories are needed to connect everything together. These include AC/DC protection, junction boxes, MC4 connectors and splitters. This cabling should be resistant to harsh weather conditions and UV rays.  

Like every thing, a photovoltaic installation also has advantages and disadvantages. The advantages of a photovoltaic installation are: 

  • Possibility of selling excess stored energy; 
  • Total access to solar energy; 
  • Independence from electricity price increases; 
  • With constant power generation, zero carbon emissions; 
  • Guaranteed for 25 or even 40 years. 

As for the disadvantages of a photovoltaic installation, the main one is its initial cost. 

Before starting the installation, it is very important to fit and check the individual components. It is necessary to analyse, for example: 

  • the possibility of positioning the panels (e.g. on the roof or ground); 
  • roof layout;  
  • type and number of photovoltaic modules; 
  • inverter selection; 
  • seasons of energy use. 

Photovoltaic installer - what does he do and his qualifications?  

The work in photovoltaics is to adapt a residential, public or commercial building to take solar energy and convert it into electricity. On the technical side, this involves installing the panels, connecting them to an inverter and connecting everything to the electrical system.  

photovoltaic rooftop fitter

Installing a photovoltaic system may seem like a simple task at first glance, but in reality it is not. There is a lot of voltage and power being generated, so an incorrect installation may cause a fire, short circuit or other hazard. For this reason, the person responsible for the installation (photovoltaic fitter) must be qualified.  

The photovoltaic installer is a relatively new profession on the market and not yet fully known to everyone. So what does his job entail? His duties include: 

  • Installation of photovoltaic systems; 
  • Inverter configuration; 
  • Electrical work; 
  • Installation of inverters together with AS-side and CD-side protection; 
  • Carrying out earthing and electrical measurements; 
  • Installation of cable routes for the photovoltaic system; 
  • Customer service care; 
  • Installation of ground and roof structures - related work. 

What qualifications should a photovoltaic installer have?  

A person who undertakes work in this industry should hold at least one of these qualifications: 

  • SEP authorisations (Association of Polish Electricians). A person who carries out electrical work should have one. This qualification certificate, which entitles you to deal with the operation of equipment, networks and installations, must be valid. 
  • Possession of a certificate that confirms the qualification to install renewable energy sources. This certificate is issued by the Office of Technical Inspection (UDT). The certificate is issued for five years. In order to obtain it, he or she must undergo training at a centre designed for this purpose and pass a state examination before a UDT commission. 
  • Be qualified to work at height. The fitter should have these, as the installation of the panels sometimes requires working on the roof, in which case he or she should observe personal protection as well as health and safety regulations. 

With an increasing number of solar panel installations, the job of a fitter seems to be a secure income. Besides, it is possible to find employment in other European countries. 

The tremendous technological development in the world in recent years, together with the development of our ecological awareness, has made photovoltaics one of the fastest growing industries these days. The largest photovoltaic markets in the world are China and the United States. In Europe, the Netherlands and Germany lead the way, followed by Spain. According to Social Power Europe's forecasts, global photovoltaic capacity will increase by 225 GW in 2023.  

In Poland, photovoltaics are also becoming more common. The installed capacity of photovoltaics in February 2021 was 4244.03 MW, and in 2022 it is more than double that. The number of new PV installations is more than 45,000 units.