10 Inverter Sizing Tips
Get It Right The First Time
- Check to make sure your inverter is marked as interactive inverter because inverters not marked with this are not permitted to operate in utility-interconnected applications.
- Check with your local utility about connection requirements.
- Watts Output: This indicates how much watts of power the inverter will be able to supply during standard operation. Check to make sure the inverter will meet the systems’s peak load demand, the inverter should be able to handle all the AC loads that could be on at any one time.
- Voltage Input: This indicates the DC input voltage and the inverter should match the nominal photovoltaic system voltage.
- Surge Capacity: Exceeding the inverters wattage rating for a limited period. Many motors have startup requirements that can draw up to 7 times the rated wattage, so make sure to check these to ensure your inverter can handle loads with surge requirements.
- Frequency: The United States uses 60 hertz which is how often electricity alternates, in this case 60 hertz means it cycles 60 times per second. Some locations may have different frequency ratings so ensure you have the proper rating for your location.
- Voltage Regulation: This is the variation of the output voltage, a good inverter can maintain an almost constant output voltage.
- Efficiency: This is a specification to pay attention to. You will see many inverters saying they are high efficiency inverters but might only be so at their peak performance, say a 300 watt inverter operating at 300 watts, that’s great and all but what if your only using 50 watts hows the efficiency then. Choose an inverter that has a broad range of loads for its high efficiency window.
- Protective Devices: Many inverters have devices built in to protect them from excessive temperatures, currents and power levels. Check to see if you inverter has these features because if it does not you will need to install additional equipment to cover these areas. Check for voltage surge suppression on the DC and AC sides also.
- Inverter interface is something you might want to pay attention to also. Many modern day inverters have displays built in that will provide basic system information, others can be hooked up with computer software for more advanced monitoring.
