Self-Contained Solar Systems

An off-grid photovoltaic power plant is called a self-contained (or stand-alone or island) system.

The operation and the location of a self-contained power supply can be represented as follows. The operational requirements and the operator’s preferences determine the type and the extent of needed components.

In practice, there are three main application areas:

1. Systems for recreational use

2. Semi-professional power supply systems

3. Professional power supply systems, hybrid systems


1. Systems for recreational use

Systems for recreational use are smaller solar plants (approx. 50 – 200 Wp) used e.g. in garden huts or caravans for lighting, entertainment electronics etc.

Direct consumption of solar power

Direct DC supply by the solar generator

With this minimum configuration consisting of a solar generator and a low electric consumer it is possible to directly supply small appliances, which are not affected by the variable output.

Stand-alone 12-24 VDC power supply with solar generator and battery storage for DC operation.

The battery charged by the charge regulator stores electrical power for low-radiation periods when the generated energy is not sufficient for operating DC appliances.

2. Semi-professional power supply systems

The so-called semi-professional power supply systems are used to provide electrical power to weekend houses with a considerably higher demand for electricity (solar plants with approx. 400 – 600 Wp). Thus, the operation of lighting and entertainment electronics as well as home appliances (especially refrigerators) can be guaranteed.

Self-contained power supply by solar generators and battery storage for AC operation.

Beside the charge regulator and the battery, an inverter is required to operate AC appliances. Surplus solar energy is stored temporarily in the battery.


Off-grid solar power plants

3. Professional power supply systems, hybrid systems

Professional power supply systems are implemented to meet the energy demands of residential buildings as well as of industrial and public facilities. These are installations with a solar generator power range of approx. 1,000 – 3,000 Wp in the private area (houses of 1 or 2 families) und of approx. 1,000 – 10,000 Wp in industrial applications. Depending on the application area, an additional power source may be used, e.g. a vegetable oil engine or a CHP unit.

Please inquire separately for semi-professional or professional power supply systems.

The extent of a stand-alone solar system depends on the consumer [W], consumption duration per hour [h] and day and on productivity of electrical appliances in a month / year (summer and winter operation).