A general rule of thumb is that you will need a 1,000 watt (1kW) inverter for every 1 kilowatt (kW) worth of solar panels. So, if you have 4 kW of solar panels, you would need at least a 4kW inverter.
Choosing the right size solar inverter is crucial for the performance and efficiency of your solar system. By considering your power needs, the type of solar panels you have, the number of panels, the length of your wires, and your battery voltage, you can determine the optimal size for your solar inverter.
What voltage does a solar inverter use?
For inverters with a relatively small amount of power like 100 watts, the voltage will be 12V, 24V and 48V. For higher powered inverters, the input voltage will likely be more. One of the factors that can affect your inverter's performance is the distance between your solar panel array and your battery bank.
This solar inverter stacking technique would be used if you had two smaller inverters but also had a solar PV system that was rated at much higher watts (power) than what a single inverter could handle. If you wired two 2000 watt inverters together in parallel, they would be able to handle 4000 watts (4KW) of power.
What size inverter do I Need?
Inverters come in different sizes starting from as little as 125 watts. The typical inverter sizes used for residential and commercial applications are between 1 and 10kW with 3 and 5kW sizes being the most common. With such an array of options, how do you find the right size for you? An inverter works best when close to its capacity.
How are solar inverters rated?
The second way solar inverters are rated is in Surge Watts. Surge watts is the amount of power the inverter can support for a very short time, usually momentary. A 2000 watt inverter rated at 4000 surge watts can handle up to 4000 watts momentarily while starting things like motors – which usually require more power than normal to get started.
Should you oversize a solar inverter?
If the solar panels have minor shading issues during certain times of the day, increase the inverter's capacity to compensate for the reduced energy generation. High outdoor temperatures will lower solar panel efficiency. So for hotter locations, oversize the inverter slightly to account for performance dips.