A solar charge controller benefits a solar plus storage system. The solar plus storage system allows consumers to utilize the solar off-grid, either on a full-time basis or as a backup at the time of power outages. The controller keeps check of the amount of energy being sent into the battery backup so that the battery does not exceed its voltage capacity. This way, the battery does not get overcharged, ultimately extending the life of a battery and avoiding any damage to it. Depending on the solar power system type, there can be a need for a solar charge controller.
- The output of a solar panel varies depending upon the level of sunlight, the quality of solar cells in the panel and the ambient temperature. All these factors affect the efficiency of solar panels in the conversion of sunlight to electricity.
- A solar charge controller smoothens out the variability so that batteries receive power at a safe and constant rate.
- It also sends a trickle charge when the battery is nearly full. It also sends across a trickle charge when the battery is nearly full. Since batteries lose a small amount of charge on a regular basis, the trickle charge keeps the battery topped off without overcharging it.
- If your solar system is operating off-grid, a controller can be considered a wise investment.
The Function and the Types
There are two main types of solar charge controllers; Maximum Power Point Tracking (MPPT) and Pulse Width Modulated (PWM).
The PWM controllers are more suited for smaller solar power systems with small batteries and low voltage panels. The MPPT controllers are on the more expensive side but come with a greater number of advantages and features. They are recommended for any solar system over 170 watts.
The most significant function of a PWM controller is to protect the battery by making sure that solar panels have the same voltage as that of a battery. The battery’s voltage must match the nominal voltage of a solar panel. As the name suggests, the PWM controller controls the flow by pulsing the power that is sent to the battery to slow down the charging or speed it up. Some of the PWM controllers can only handle a single voltage level, while the others can handle multiple levels.
MPPT controllers, unlike the PWM systems, hold the capacity to charge a lower voltage battery from a higher voltage array and, in some cases, even a higher voltage battery from a lower voltage array. In an electrical system, the amperage and voltage are inversely related. The higher the voltage, the lower will be the amperage. The MPPT controllers can greatly increase the efficiency of a solar panel by 20 to 30 per cent. It achieves so by keeping track of the optimal voltage to the current ratio in order to maximize the battery’s output. It is the increased efficiency that makes the cost of MPPT solar charge controllers worth it.
The simplest PWM solar charge controllers cost less. The ones with additional features cost more. The MPPT controllers, on the other hand, can convert the high output solar array to lower battery voltage as the battery can capture the sun’s energy better. This not only increases the efficiency but also shortens the payback period of the system.
When it comes to solar products, it is always better to anticipate your solar capabilities and needs. Make sure to calculate the payback time and costs in order to understand what kind of system works the best for you.
Luminous is the pioneer of solar power solutions in India and comes with a range of solar controllers that help convert the existent power backup system into a solar system with minimal investment.