The inverter is the heart of the solar photovoltaic system, and more than 90% of solar system failures causes is due to inverter malfunction. There are 2 main factors affecting solar inverter selecting, inverter performance and its price.
The solar inverters differ based on six parameters, in which we have to consider when choosing the best solar inverter to our system, as following:
- The solar inverter power capacity in watt, and it refers to how much power it can provide. In the market there are many different standard inverter capacities, for different applications whether its residential, commercial or industrial application. For example, the residential solar inverter power capacities exist on the market are 1600W, 2000W, 3000W, 4000W, 5000W and 10000W.
- The solar inverter startup voltage, it refers to the lowest DC voltage value in which the inverter will start running and converts DC power to AC power, in other word, at what level of sunshine the solar inverter will run. The startup voltage depends on the inverter power capacity and its brand and it usually vary from 95V to 150V.
- The solar inverter surge/inrush power capability, it refers to how much power it can deliver and how long it can withstand at starting period for motors and others which requires much power at starting period. For example, the motors pull approx. 6 times "larger" its rated power capacity at starting period, and this lasts from 1-5 seconds.
- The solar inverter efficiency, it refers to inverter output power to its input power ratio, in other word, the inverter internal losses. Also, how much power the solar inverter consumes when it is on idle condition. Usually solar inverter efficiency is above 90%, and most of them consume very low wattage on idle condition.
- Solar inverter output waveform shape, is it pure sine wave or modified sine wave? This is an important factor in indicting the inverter quality. Mind that most of loads requires pure sine wave shape for better performance.
- Will the solar inverter support monitoring and management software, so you can monitor the system and take corrective action when needed? How will you be able to connect to the inverter, is it via wireless router or Ethernet?
It’s really important to carefully select the best and high quality solar inverter, because this will result to higher efficiency and longer life span solar system, its meaningless to choose high quality solar panels and low quality solar inverter while solar inverter is the heart and most important part in the solar system.