Types of Solar Electric Systems

Types of Solar Electric Systems

A solar electric system is typically made up of solar panels, an inverter, a battery, a charge controller, wiring, and support structure. The three most common types of solar electric systems are grid-connected, grid-connected with battery backup, and off-grid (stand-alone). Each has distinct applications and components

A&T Power Systems–Grid- Connected

In this system, the solar panels are connected to your local utility electrical grid to complement your normal power supply from your utility company. Grid-connected systems consist of:

  • Solar panels mounted on the roof
  • An inverter to convert electricity produced by the system from direct current (DC) energy into alternating current (AC) energy
  • A junction box that connects the solar panel wiring to the breaker panel on the home
  • A power meter that displays how much power the home produces and uses
  • A disconnect switch that, for safety reasons, prevents the system from sending power to the grid during power outages (this is called islanding).

A&T Power Systems–Grid-Connected with Battery Backup

Very similar to the grid-connected system, this system adds a “battery bank” to collect the power generated from the solar panels. Power stored in the batteries can be used during power outages. The battery bank collects power produced by the solar panels, sends it to the breaker box, and then into the house power system. The components of this type of system consist of:

  •   Solar panels mounted on the roof
  • An inverter to convert solar electricity from DC energy into AC energy
  • A battery bank for power storage
  • A charge controller to prevent overcharging the battery
  • A junction box that connects the solar panel wiring to the breaker panel on the home
  • A power meter that displays the amount of power used, produced, and stored in the battery bank
  • A disconnect switch to prevent islanding during power outages.

A&T Power Systems —Off-Grid or Stand-Alone

Off-grid systems are not tied to any utility power lines and are most common in remote areas where connecting to the utility grid is more expensive than purchasing an off-grid system. In off-grid systems, the solar electric system represents the home’s main source of power. Batteries store unused solar energy for use at night.

Generators, small wind systems, and other backup fuel sources are sometimes used as backup power when the solar power stored in the batteries is not enough to meet household needs. These systems consist of the following:

  • Solar panels mounted on the roof
  • An inverter to convert electricity produced by the system from DC into AC energy
  • A rectifier (sometimes used to change AC to DC and back again to get the most use out of a system)
  • A charge controller to prevent overcharging the battery
  • A junction box that connects the solar panel wiring to the breaker panel on the home
  • A junction box for backup power supply from a generator
  • A power meter that displays the amount of power used, produced, and stored in the battery bank
  • A disconnect switch to prevent islanding during power outages.

A&T Power Systems —Solar Pumping System.

A solar water pump has a mini power house at its heart and consists of a calibrated and matching solar array of modules – tuned with the equivalent power of pump for that particular application. The solar water pumping system is capable of running all types of electrical water pumps with applications varying from irrigation to household demands. Irrigation pumps such as submersible, surface or deep well can also be coupled with drip irrigation systems to enhance the returns from this configuration.

A typical solar water pumping system is known by the sum total of solar array size that is required to run the attached pump. A 1000 Wp solar water pump is capable of drawing and pumping approximately 40,000 litres of water per day from a source that is up to 10 meters deep. This is sufficient to irrigate about 2 acres of land with regular crops. A 1000 Wp solar water pump helps save up to Rs 45,000 when compared to equivalent use of a diesel-operated pump over a year.

 

  • Each solar array has a number of solar modules connected in parallel or series. Every solar PV panel generates current by converting solar radiation to electrical energy.
  • The electrical energy from the entire array is controlled, tuned and directed by the inbuilt controller in DC pumps or through the Variable Frequency Driver(VFD) and enables the connected pump (may be submersible or surface) to draw water and feed the delivery pipelines.
  • The water thus drawn from ponds, rivers, bore wells or other sources by a solar water pump is pumped to supply water as required. It can be stored in tanks from where it is later channelled to fields or the supply from the pump may be coupled with drip irrigation systems to provide optimised water to fields directly.