Stand-alone power supply systems
Photovoltaic systems in stand-alone or island mode are used everywhere, where
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no public electricity grid is available (weekend house, garden shed, locally isolated garages,...)
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autonomous consumers require little energy (gate operators, automatic pumps for irrigation, outdoor lightning,...)
The produced electricity is stored in batteries and can power electrical loads with 12/24V DC via a load controller. Modern systems use an inverter, which supplies 230 V AC power to common consummers.
In case sun doesn't shine enough over several days, the installation (batteries, PV-array) needs to be over-designed or a generator (diesel generator) needs to cover this period.
A design of the stand-alone system requires the determination of the energy consumption and the daily/weekly working hours of each electrical device:
Daily energy consumption[Wh] = Sum [Device performance x daily operating hours]
The daily required energy to charge the batteries is calculated by the number of operating days in a week:
Daily required charging energy[Wh] = Daily energy consumption x Operation days in a week/7
Some consumers (water pumps for fountains, fans) are connected without batteries directly to photovoltaic modules if they are to be operated only at sunshine.
There is no financial support from Luxembourg State for these installations!