Photovoltaic Systems Off-Grid

Off-grid photovoltaic systems are not connected to the public power grid. Raach Solar implements systems for various purposes – battery storage systems, power supply systems for villages or telecom system as well as hybrid solar power plants.


The difference between an AC Solar Home System (SHS) and a DC Solar Home System is the standard single phase 230 VAC output voltage by an additional inverter and higher solar array power between 1 kWP and 5 kWP. With such an independant solar power supply, you can run standard home appliances such as regfrigerators, electric irons, television sets, lights and computers.

photovoltaic pumping systems (PVPS)

Solar pumping systems are one of the most economic applications because they run without batteries. At sunrise the systems starts to pump water, at sunset the pump stops to delivery water. Not electricity is stored, bzt usually water is stored in a water tank. Key component is the pump inverter which can be an external unit or an external unit or an built in into the pump. This pump inverter or referrend to as well “variable speed drive (VSD)” transforms the direct voltage from the solar modules into three phase alternating voltage to power the motor of the pump.

Photovoltaic pumping systems. Bild

village power supplies (AC mini grids)

Village power supplies (VPS) deliver a low voltage three phase grid (3 x 400 VAC) to houses, compounds or complete villages. The typical power rating is between small scale 10 kWp up to medium scale 1 MWp of solar modules. The advantage of its modular design it to add at a later stage more solar module and battery stage more solar module and battery storage capacity. The brain of the system os the master inverter-charger which generates the thress phase off grid (as shown as loads on the drawing above) and controls the energy flows depending in the state of charge (SOC) of the battery. The AC distribution box “multi cluster box” combines all sources, solar power, battery power and as back up, if available, the public grid or diesel generator to supply the loads.

solar power supplies for telecom stations

Telecom devices for remote internet, mobile phones or repeater stations need 48 VDC power supplies. Solar power turns out to be the more economic and technically more reliable power supply than diesel generators in remote areas or urban areas with frequent power outages. The key component is the DC/DC solar charge controller which charges the 48 VDC battery and supplies the telecom loads. Typical power ratings of these solar power supplies are between 5 kWp and 30 kWp.

Cathodic corrosion protection systems (oil & gas)

Underground or on ground oil & gas pipelines corrode in dry and humid environments. In order to reverse the corrosion process, solar power, solar power systems inject electricity by electrodes. A key component is the cathodic protection charge controller which measures the different electric potential between the pipeline and the ground. The loads are electrodes which are supplied by a variable DC direct current to reverse the corrosion process. Solar systems for this application have a typical power rating between 10 kWp and 50 kWp.

solar streetlights

Solar-powered street lights use modern high efficient LED technology to illuminate streets and pathways. Key element is the street light charge controller which senses through the solar modules the difference between day and night. The start & stop time of lighting is field adjustable. Different battery technologies such as lithium, nickel or lead can be used. Tailor made designs are available.

solar home systems

DC solar home systems are made for basic rural electrification with electric loads which only require 12 V/24 VDC supply voltage. Technological progress has been made to develop special high efficiency DC loads such as LED lights, radio, flat screen TV sets and notebooks. Low energy consumption at a high level of comfort has reduced the size of solar modules and battery capacity.

hybrid photovoltaic power plants (>10 MWp)

On ground photovoltaic power plants can be designed as large scale independent medium voltage off-grid power plants. Currently, photovoltaic power is one of the most economic and clean source of electricity and outperforms other sources such as wind power or fossil fuel powered generators. After analysing the load profile, RAACH SOLAR uses specially design software to engineer the size of the photovoltaic power plant and the required storage capacity.

There are several configurations possible:

  1. Photovoltaic – battery storage power plant
  2. Photovoltaic – wind energy – battery storage power plant
  3. Photovoltaic – wind energy – battery storage – diesel generator back up power plant