Today it is possible for solar power users to store their solar production by using inverter battery. The presence of solar battery can help to optimize the solar power. Solar battery is used to store the solar power. In other words, by installing the solar battery users could save the electricity bill.
Adding a solar battery to a photovoltaic system will bring you many benefits. But it does not mean, by having a battery bank, that you can waste your electricity! In fact, the benefits of a solar power system with battery depends on your electricity consumption level.
Solar innverter system has two types of inverter batteries, lead acid battery and lithium battery. The use of lead battery has been known for decades. In the last few years, the presence of lithium battery began to bet the lead battery. Although the price of lithium batteries is today more expensive but decreasing fast and able to give maximum results with a better lifespan.
Differences between Lithium and Lead-acid solar battery
Lithium battery was introduced in the 1970s. It provides a high density level and lighter than lead acid battery. The production of lithium solar battery requires less material, it able to minimize environmental pollution and create a cleaner technology. Meanwhile, the production of lead solar battery requires a lot of material. The main component of the battery which is the lead, is one that cause the environmental pollution, so it can be said that the lead acid battery is not ecological friendly.
In determining the solar battery one of the important things to do is looking the value of DoD. Depth of Discharge or DoD is used to describe how deep the battery is discharging the power and how much energy can be sent.
The lifespan of lithium battery is about 8 to 16 years with a 3000-6000 cycles at 80% DoD. While lead acid battery is only have 400-800 cycles at 50% DoD for AGM and gel types, and 1000-8000 cycles at 50% DoD for OPZ and OPZS types. The battery life depends on each battery manufacturer and the environmental conditions. Such as if the weather is too extreme and having poor maintenance, it can affect the performance of solar battery. For example when the weather reaches 0 ° F (-17°C) the lithium battery power is reduced by 10% of its total potential, while the lead acid battery power can be reduced by 40 to 60%.
Advantages of using solar battery
Here are some benefits that you can gain by adding solar batteries to your photovoltaic installation
1. Power supplier
By using solar battery, the production of electricity generated by solar panels can be stored and used later. The presence of a solar battery can prevents when the solar production is poor and if there is a problem with the grid. Thanks to the solar battery, users can have electricity in the evening or do not have to take electricity from the grid when the solar production is under the house needs. With solar batteries you maximize your ability to use the electricity generated by your photovoltaic system.
The larger the capacity of the battery, the more electricity that can be stored. It also depends on the type of battery, and on the solar system type that is installed in your home.
2. Decrease electricity bill
Increasing the electricity costs only get worse over time. One way to save your electricity bills is to install a solar battery. The energy contained in solar battery can use to power your home appliances. In the meantime at the same condition when the electricity surges, usually at night, you no longer have to worry about surging the electricity costs, because the energy reserves on the battery can supply power to your home and prevent you from high bill.
If the solar production has no excess to feed the battery you can decide to fill them with the grid during the hours when the price of kWh is low and use them when the price of the grid kWh is high.
3. Transportable and environmental friendliness
The use of battery is a solution for isolated areas and areas that have limited power supply. Solar battery can be transported anywhere. As long as there is the sunshine you can get the electricity supply anywhere. This is seen as a security but also an important gesture for the planet.
Solar Charge Controller
Solar charger controller on the battery is aimed to control the voltage and avoid the solar battery from overcharging. There are two types of the charge controllers, MPPT (Maximum Power Tracking Charge Controller) and PWM (Pulse Width Modulation). The MPPT charge controller is more expensive but more efficient, while the PWM charge controller is cheaper but less efficient. The PWM directly connects the panel PV to the solar battery. Meanwhile, the MPPT is designed accurately to adjust the voltage of the solar panel with the battery system. This charging is considered to be the most efficient, because the power going into the solar charge controller is equal to the power released.
Comparison of MPPT and PWM:
- The quality of battery charging
MPPT will certainly be superior in battery charging than PWM. Due to MPPT can detect the production of panels to fill the battery capacity. While PWM is only able to adjust into the battery voltage.
- Capacity of solar panel system
The PWM voltage is only able to adjust to the battery voltage. So if the voltage generated by the solar panel is below the battery voltage, the solar panel system will not automatically charge the battery. Therefore, PWM is not recommended to be used for solar panel capacity systems above 200 Wp. Meanwhile, MPPT solar charge controller is able to maximize the charging capacity, because MPPT is able to detect the power produced by solar panels.
- Load ratio and array system
In this case PWM can be used if the output array produces higher power than the load ratio. If the array output produces more power equal to the load ratio, then MPPT is preferred for use. It’s because, if the voltage falls below the battery voltage, MPPT can stabilize the solar panel system. Meanwhile, PWM is not able to stabilize the solar panel system in this case. MPPT solar charge controller can reach the efficiency until 90%. While the PWM solar charge controller only reaches 80%. If you use PWM then, you have to equalize the voltage of the solar panel with the voltage of the inverter battery. For MPPT, panel voltage must be greater than battery voltage to provide maximum power.
Some aspect you can consider before buying an inverter battery:
- If you use a solar battery, do not forget to adjust the battery voltage to the inverter voltage, so the battery can provide maximum results for the inverter.
- Knowing how long long it takes to fully charge the solar battery before use by the inverter. Currently, there are many inverters that have the features to know the battery power.
- When buying an inverter choose the safest one. Make sure the inverter product and its components have been tested feasibly. Inverter with cheap price usually does not have good quality and cannot last long.
- Note the Voltage Ampere of an inverter to coordinate the inverter load with the required load. In some cases if your equipment has a higher load than the load of the inverter, the system of inverter might stop working. Some inverter also equipped with LCD indicator and applications to help you manage solar production and track battery status.