Glossary 

Alternating current (AC)

A type of electrical current, the direction of which is reversed at regular intervals or cycles.

Amorphous cells

These cells are also called thin film cells. They are made of very thin consecutive layers of atoms, molecules and ions. The thickness range of such a layer varies. These modules can be produced at a much lower cost than PV modules with monocrystalline or polycrystalline cells. Amorphous solar cells are increasingly used for large scale installations.

Autonomous solar systems

These solar systems are also known as off-grid systems. Autonomous solar energy systems provide reliable, battery-buffered power supply in areas with no or unreliable power networks. These solar power systems can be mobile or permanent.

Batteries

Solar panels generate electricity only when the sun is shining, but they do not store energy. The obligatory battery is the heart of the autonomous solar system and must be carefully selected and dimensioned to avoid poor overall performance.

Charge controllers

The energy flow from the batteries to the load must be managed. The charge controller is a component of the photovoltaic system that controls this flow of current to and from the battery to protect it from over-charging and over-discharging. 

Direct current (DC)

A type of electricity transmission and distribution by which electricity flows in one direction through the conductor, usually with relatively low voltage and high current.

Grid-connected solar systems

These solar systems feed electricity generated through solar power into the public grid. A grid connected solar system supplies electricity to the grid which is not used by your home and draws electricity from the grid, when the solar panels do not produce sufficient electricity to meet the demand.

Inverters

The inverter is an integral part of most solar systems. An inverter transforms direct current electricity to alternating current either for stand-alone systems or to supply power to an electricity grid. Central inverters are used in large photovoltaic systems, and string inverters in small photovoltaic systems.

Monocrystalline cells

These cells are made from crystalline silicon in which the wafer is cut from a single silicon crystal with a perfect crystalline lattice structure. Monocrystalline modules are the best choice where the space of installation is limited as these modules are the ones with the highest level of efficiency.

Mounting systems

Mounting systems are needed to safely attach PV modules on a roof or adjacent structure. The majority of solar systems are mounted on or integrated in a roof.

Multicrystalline cells

See polycrystalline cells

Off-grid systems

See autonomous systems.

Polycristalline cells

These cells are also known as multicrystalline cells. They consist of a wafer with a multi-grained structure. All grains have the same atomic crystal lattice. Each grain has an unique orientation in space thereby producing a unique reflection of light. These modules are used where there is plenty space available to compensate for the lower efficiency.   

PV modules

Photovoltaic (PV) modules are also known as solar modules. They consist of an assembly of solar cells intended to generate direct current power under unconcentrated sunlight. Typically, photovoltaic modules are attached inside a frame on the roof or to a supporting frame.

Roof integrated system

A type of mounting system where the solar modules are integrated in the roof. For this type of construction tiles must be taken out.

Roof mounted system

A type of attachment system where the solar modules are mounted on top of the roof. The roof covering itself is not being affected by this system.

Solar kits

Solar kits are standardised solutions to generate electricity in regions without reliable power network, offering economically priced solutions for standardised applications.

Solar modules

See PV modules.

Solar thermal systems

These systems provide hot water powered by the sun. A compact solar thermal installation will cover an average domestic hot water demand 24 hours a day. Unlike hot water systems based on electrical heating, solar thermal systems do not cause any operating costs.

Solar-powered water pumps

Solar-powered water pumping systems operate with solar modules which produce electricity to power the submersible water pump which pumps the water into a water tower. There the water is stored in a tank. This allows a reliable water supply. Due to hydraulic pressure the water then runs into the irrigation system or tap.

Thin film cells

See amorphous cells.

Watt peak – Solar modules are rated in Watt peak which is the direct current (DC) watts output of a solar panel as measured under standard test laboratory conditions at works.