PV applications

PV systems can either be connected to the public power grid (grid-connected systems) or operated autonomously (stand-alone systems).

Grid-connected systems

Most photovoltaic systems feed the generated power into the public grid. This is called grid operation of grid-connected systems. Connecting the solar installation to a large grid guarantees that there are always enough consumers available for using the solar energy directly and eliminates the need for local intermediate storage. Power supply is ensured at all times and normal alternating current appliances can be used.

Today, self-consumption of solar electricity is often key for a PV system’s profitability. What does this mean? The more solar power is used directly at the system’s production site as soon as it is generated, the quicker a PV plant will pay off financially (for more information, please visit SwissEnergy).

To increase the self-consumption rate, solar power can be used to produce heat, which is easier to store. From an energy efficiency perspective, it is preferable to use solar electricity to operate heat pumps. The heat pump’s control must be coupled to the PV system in order to ensure the heat pump is perfectly integrated. Installers will be happy to assist you with these tasks.

The electricity surpluses are fed into the public power grid and refunded by the local grid operator. According to Art. 11 § 1 of the Swiss Energy Ordinance (EnV), grid operators are obligated to acquire the extra power produced. Art. 12 § 1 EnV defines the remuneration as being based on the costs the grid operators would incur if they were to acquire equivalent third-party electricity, as well as on the initial cost of their own production plants. There are considerable differences in the redelivery refunds paid: see www.pvtarif.ch.

Several apartments or adjoining plots of land can share the power produced by one PV system within private consumption communities (ZEV), thus also increasing the self-consumption rate. More information

Stand-alone systems

Remote objects, such as mountain cabins, holiday homes, SOS phones and parking meters, can use power provided by stand-alone solar installations with batteries (power storage). This is called isolated operation.

These are the features of a stand-alone system:  

  • a cost-saving alternative to connecting remote consumers to the grid;

  • operation is generally based on continuous current with a 12 V or 24 V voltage; this operation requires special devices and lamps if no inverter is used;
  • this type of PV system generally consists of three components: the solar generator, the charge controllers and the batteries.