About Solar power
Here you’ll find useful information on the subject of photovoltaics.
- Cost-effectiveness/Return on investment Thanks to state and federal incentives, operators of solar power systems are guaranteed remuneration from network operators for any power fed into the grid for a period of 20 years. And, when viewed in terms of the overall economy, power generated from renewable energies has a cost-cutting effect!
- Environmental protection and health Solar power is clean. It produces no harmful emissions and is also silent.
- Preserving resources Our resources are becoming scarce. Oil, natural gas and uranium will run out. The energy from the sun is practically inexhaustible and is available to anyone, anywhere.
- Sustainability To make sure we look after our natural assets for the next generation, we should only use what can be replaced. Solar power is regenerative.
- Freedom from power utilities As the power supply is decentralized, the large power utilities lose their enormous influence, leading to a more democratic playing field.
- Energy efficiency Line losses of around 64% are common where electricity comes from a power plant. This means that of every 1,000 watts, just one third i.e. 360 watts actually reaches us.
- Set an example Live according to the motto: “Act in a way that can set an example for everyone.”
For 4 billion years, the sun’s radiation has been supplying the Earth with heat and light – without which life would not be possible. This radiation (= photons) is generated by nuclear fusion in the sun’s core. When a photon hits a silicon atom, its electrons are knocked out of place, which creates an electrical charge. As a result of this process, radiation is converted directly into electrical energy. This is known as the photovoltaic effect. In Lithuanian, an average of 1,000 kWh of solar energy per metre squared can be produced each year. This is equivalent to the energy content of 100 litres of fuel oil.
HOW PHOTOVOLTAICS WORKS
Photovoltaic systems can be connected, via a network operator, to the public electricity grid to feed in power (on-grid systems) or they can be used for self-sufficiency purposes (off-grid systems). A photovoltaic system incorporates the following components:
Solar module (interconnected assembly of solar cells)
Storage system optionally
In principle, photovoltaic systems can be installed on flat or pitched roofs, can be integrated into the facade of a building or can be set up on open land.
A solar module consists of electrically connected solar cells. In a solar module, the individual cells are soldered into a row to form electrically connected cell strings. The cell strings are connected to cell plates by diodes and laminated into a vacuum between support glass, EVA film and Tedlar film. An aluminium frame binds the completed laminate unit. There are three types of solar cell:
Monocrystalline solar cells: Are cut into thin slices (wafers) from a pulled silicon rod with an even crystal structure (monocrystal). They are dark blue or black in colour.
Polycrystalline solar cells: Are cut from a cast silicon block. The poly cells look bright blue.
Thin-film solar cells
As a basic rule, monocrystalline solar cells work more efficiently, but are a little more expensive to produce.
The inverter converts the direct current (DC) produced by the solar modules into alternating current (AC). This is then fed into the public electricity grid. Depending on the model being used, one or more module strings can be connected to a string inverter. System control devices (data communication) are used to monitor the power produced, how much electricity is consumed and how much is fed into the grid.