Solar Sources

Scope

This document describes the various components required to provide a Solar powered backup system for a Comb Communications Intercom and gate system.

Disclaimer

Solar Panels

A solar panel is a device that converts sunlight into electricity by using photovoltaic (PV) cells. The Solar panel must be matched to the solar charger.

Solar Charge Controller or Solar Regulator

A device that regulates the electric current from the solar panels to the battery bank. The charge controller has the following features:

Current regulation: Prevents battery overcharging.
Battery protection: Once the battery is fully charged it will maintains the voltage and current.
Load control: Prevents the battery from over discharge.
Monitor and display: Shows the state of, for example, battery voltage and load power.

Types of Solar Charges

PWM (Pulse-width Modulation): Basic type of charging that rapidly switches the solar panel output on and off. Cost-effective and suitable for small systems.

MPPT (Maximum Power Point Tracking): A more advance type of charger that tracks the maximum power point and adjusts the output power. This type of charger can be up to 30% more efficient than the standard PWM charger.

Factors to consider when selecting a Solar charger are the system voltage (12V, 24V,48V, etc.), maximum current and voltage supplied by the solar panel, maximum battery charge current and battery type (Lead acid, Lithium, etc.).

Batteries

Flooded Lead Acid: Affordable and reliable. Require periodic replenishing of distilled water, have a shorter life span than Lithium-Ion type of batteries. Performance is degraded by deep discharging the battery.
Sealed Lead-Acid: Sealed, requiring less maintenance. Performance is degraded by deep discharging the battery.
Gel: Better handling of deep discharge cycles. No maintenance required. Sensitive to higher temperatures. More costly than the normal lead-acid battery.
Lithium-Ion: Higher energy density, lightweight and longer lifespan. More expensive than the lead-acid battery. Lithium-Ion have a better deep discharge capability.
Lithium Iron Phosphate (LiFePO4): Longer lifespan, higher thermal stability

Wiring Diagrams

Comb Intercom

Suggested Components
Solar Panel: 2 x 12V 50W in series.

Solar Charge Controller: 12V 20A. Charge controller must support selected battery type (Lead-acid or Lithium-Ion).

Battery: 12V 33Ah.

A DC to DC converter 12V to 15V.

Comb Intercom and a Gate Motor

Suggested Components
Solar Panel: 1 x 12V 100W or 2 x 12V 50W

Solar Charge Controller: 12V 20A. Charge controller must support selected battery type (Lead-acid or Lithium-Ion)

Battery: 12V 33Ah

Gate Motor

Suggested Components
Solar Panel: 1 x 12V 100W or 2 x 12V 50W

Solar Charge Controller: 12V 20A. Charge controller must support selected battery type (Lead-acid or Lithium-Ion)

Battery: 12V 33Ah