Solar modules

Solar panels, or photovoltaic (PV) modules, are at the heart of PV systems. They contain solar cells, connected in parallel or in series, and these convert solar radiation into electrical energy – your solar power.  

In residential and small business environments, solar modules are usually mounted on the roof of the building. The output from the PV system that results from connecting all the modules depends on many factors, such as the number of modules, the module type and performance, the roof pitch, and amount of sunshine.  

Solar modules consist of several solar cells connected in series or in parallel. These are protected by a tempered glass pane, which forms the top layer of the module, and a film underneath. The sun’s rays penetrate the two transparent layers and then hit the solar cells, which convert the UV radiation into electricity. On the reverse side, the cells are protected by a foil in the case of glass-foil modules or another glass pane in the case of glass-glass modules. 

Solar modules were developed back in the late 1950s for the space industry, to supply satellites with electricity. The oil crisis in the 1970s was ultimately the catalyst that spurred the construction of solar products for everyday applications. This led to the development of electrical devices such as pocket calculators or wristwatches powered by solar cells. Similarly, solar cells were also used in signalling systems and parking machines. At the same time, the first large-scale photovoltaic power plants were built to supply energy. Inexpensive thin-film modules were and still are mainly used in large-scale solar farms. 

The idea of a decentralised energy supply, in which each building is fitted with its own photovoltaic system, emerged in the 1980s and has become more popular over time. Today solar modules are built and used all over the world. Photovoltaic technology has established itself as a pillar of green, renewable and sustainable energy supply. 

Mono- or polycrystalline solar modules, PERC technology 

The difference between monocrystalline and polycrystalline solar cells lies in the production process. While the silicon used to create monocrystalline cells is grown in a complex process, the silicon used to create polycrystalline solar cells can be heated and moulded into shape. Solar modules based on monocrystalline solar cells have a high efficiency of up to 22%. The efficiency of polycrystalline photovoltaic modules can be up to 20%. Both cell types are suitable for all applications. However, where there is limited space available on the roof, more energy can be generated using monocrystalline solar cells. Monocrystalline modules are more durable and, viewed over their lifetime, more economical than polycrystalline modules. However, polycrystalline modules are cheaper due to their simpler production. 

PERC technology (PERC = passivated emitter and rear cell, or rear contact) can increase the efficiency of solar cells by 1% or more. The passivation of the emitter and rear contact increases the light absorption and reduces electrical losses. 

Glass-glass or glass-foil modules 

Aside from output and yield, mechanical strength and protection against environmental and weather influences are key considerations when choosing solar modules. Glass-glass modules are extremely robust, able to withstand considerable external influences, making them highly durable. They also offer very high yield stability. The result is that you can generate higher amounts of solar power from your roof for longer from your single investment. 

The right solar module for every need 

With such an abundance of offerings on the market, it can be hard to find the right solar panel for you. Consider the following questions to help you narrow down your selection: 

• What output do you want to achieve? 
• How much space is available? 
• What should the system look like? 
• Do you want to install an in-roof or on-roof system? 
• What region do you want to install the system in? 
• What is the purpose of the PV system?