Maximum efficiency
Inverter efficiency for solar panels.
The efficiency indicator is the percentage ratio between the amount of energy that the device delivers to the load and the energy consumed from the solar panel. The higher this parameter, the more efficient the operation of the device and the lower the losses during conversion. In modern inverters for solar panels, efficiency values of up to 90% are considered average, and above 90% are considered good.
Rated power
The rated output power of the inverter, expressed in volt-amperes (VA). Essentially, this value is equivalent to power in watts (W).
This parameter refers to the power that the device can continuously deliver to consumers. When choosing based on this parameter, ensure that the rated power of the inverter exceeds the expected load power by approximately 15-20%. Additionally, keep in mind that some electrical appliances (particularly those with electric motors, such as vacuum cleaners, refrigerators, etc.) consume significantly more energy at startup than during regular operation. For such loads, it's important to check the peak power of the inverter (see the relevant paragraph) — it should be higher than the starting power of the load.
Rated power
The rated output power of the inverter, expressed in watts (W).
This parameter means the power that the device can provide to consumers for an unlimited time. It is necessary to choose according to this indicator so that the rated power of the inverter covers the power consumption of the expected load by approximately 15-20%. It is also worth considering that some electrical appliances (in particular, units with electric motors - vacuum cleaners, refrigerators, etc.) consume significantly more energy when starting up than after entering the mode. For such a load, it is also necessary to clarify the peak power of the inverter (see the corresponding paragraph) - it should be higher than the starting power of the load.
Peak power
The highest total output power in watts (W) that the inverter can deliver to a load for a relatively short period of time, on the order of 2 to 3 seconds. As a rule, this power is 30 - 50% more than the rated power (see above). The peak load value can be useful when calculating how the inverter works together with appliances that consume a lot of energy at start-up (vacuum cleaners, borehole pumps, power tools, etc.). The rule here is simple - the peak power of the inverter must not be lower than the starting power of the load.
Maximum charge current
The maximum amount of direct current in amperes that the inverter can convert. If the solar panel produces a current exceeding this value, the inverter simply does not use it. This is often justified when connecting an inverter to high-power solar panels - the maximum input current of the inverter is reduced to acceptable values so that moderate-sized wires can be used to transmit energy.
Max. power
The maximum allowable input power from solar panels, expressed in kilowatts (kW). Let us remember that 1 kW contains 1000 W.
When selecting an inverter based on this indicator, they are based on the total power of the solar panels involved in generating electricity. Moreover, it often makes sense to select models with an inverter input power slightly less than the maximum power of solar panels - for example, if they are shaded part of the time or for other reasons do not receive enough sunlight during the day. The power of the solar battery should not exceed the power of the inverter by more than 30%. However, for some inverters the excess can be only 10%, while for others it can be up to 100%. It is better to clarify this point in advance.
Operating voltage PV
The operating range of the inverter is usually located between the starting voltage and the maximum voltage. This interval is indicated in volts.
Short circuit current
The maximum solar panel short circuit current that the inverter can accept without the risk of breakdown or emergency shutdown. The parameter is usually indicated in amperes.
MPPT controller(s)
Built-in Maximum Power Point Tracking (MPPT) system for monitoring the maximum power points of photovoltaic modules in solar panels. It determines the most optimal ratio of voltage and current drawn from the solar panels, thereby ensuring maximum performance of individual strings (chains of series-connected panels). An
MPPT controller is useful under any external weather changes, allowing solar panels to generate power even in cloudy conditions. Modern inverter models can contain either one or
several MPPT trackers (up to six), which allow for the connection of multiple arrays with different orientations and angles of inclination, thereby eliminating the mutual influence of one array on another. Each MPPT controller output is designed to connect one string.
