On grid
On grid is a system connected to the distribution network from which it is replenished to the required power or the excess produced power is sent (eg the principle of negative meter: when the meter is sent it takes away the consumed energy and thus reduces the bill).
They provide a normal supply of electricity regardless of the time of day, season and climatic conditions. Such a system requires additional contracts with the electricity distribution agency, and can greatly speed up the repayment period of the entire photo voltaic system.
Components
- Solar panel
- Charge controlers
- Inverter
- Battery unit(s)

Off grid
Components
- Solar panel
- Charge controlers
- Inverter
- Battery unit(s)
Off grid systems is suitable for power supply where it is impossible or very difficult to deliver the distribution system. Although as it ensures complete independence of electricity exploitation, there is also an eliminated financial burden on users (except at the time of repayment).
The photovoltaic system charges the battery bank (batteries connected in series or in parallel) during the day and the accumulated energy is pumped from it at night. During the day, it is also possible to connect directly to consumers. An additional supply can be provided by a connected generator as an optional power source. This system is more expensive, at least by 30% because the battery bank costs a lot and their service life is 5-15 years (depending on the method of exploitation).