Are you lost in the terminology of the solar installation types? Read our beginner's guide:
Also known as “tied to grid”, or “grid-tie” system. This type of installation is aimed to make a profit by generating energy which is directly supplied to the grid. In some configurations, part of the energy may be used for the self-consumption however all the excess electricity is supplied to the grid. As a result, this type of installation needs to be connected to the grid which is realized by an inverter that generates electricity that is phase-matched to the mains.
Optionally batteries may be used. When batteries are used for storage, the system is called battery-to-grid (B2G).
Example of a grid-tied installation with a battery: https://www.ev-power.eu/index.php?cl=knowledgebase&KBId=1373
It is a subtype of the grid-tied installations. The difference is that the solar panels and inverters are connected only when there is a self-consumption. Thus, GridFree installation is used only to lower the energy consumption from the grid. This type of installation is a solution in countries where it is illegal to supply any access energy back to the grid. (like in Czechia or in China) The GridFree installation is connected to the grid but does not send the excess electricity out – back to the grid. All energy is consumed within the installation place – the production is always lower than consumption.
More about GridFree: https://www.ev-power.eu/GridFree-Meter/ and
A solar installation fully separated from the grid. The excess electricity is stored in a battery that is necessary for the system to function. Every off-grid system must have a battery. The whole system usually consists of the battery, solar panel, MPPT regulator and a DC/AC inverter.
Example of an off-grid installation: https://www.ev-power.eu/blog/Solar-panels/Making-small-off-grid-power-system.html
Combination of the above-mentioned types: It can switch between the grid-ties modes (the system can be connected or disconnected to the grid). It needs a battery and an inverter to function properly.
Example of a hybrid-grid installation: https://www.ev-power.eu/blog/Solar-regulators/Example-of-a-hybrid-grid-FV-installation-with-energy-storage.html
List of illustrative pictures:
1) Grid-Tied Energy Storage Solution
2) Off-grid solutions: solar chargers (charge controllers), wind-turbine invertors, UPS…
3) Off-grid Solar Installation with MPPT regulator
4) Example of a grid-free solar solution
5) Hybrid grid installation with Victron components
6) Example of a hybrid grid installation with energy storage