Quick Answer
Modified Sine Wave Inverters may work for basic solar water heaters, but they are less efficient and may cause issues with some water heater models.
Inverter Compatibility
Modified Sine Wave (MSW) inverters can provide a viable alternative for basic solar water heater systems, especially those with simple electrical requirements. In general, a MSW inverter with a high peak current rating (e.g., 20 or 30 amps) is necessary for handling the surge current of a solar water heater’s heating element. A minimum 1500-watt MSW inverter is recommended for a basic solar water heating system with a single 240-volt element.
Efficiency Considerations
When comparing MSW and Pure Sine Wave (PSW) inverters, the primary difference lies in their efficiency and compatibility with sensitive electrical loads. PSW inverters, which mimic the sine wave output of a utility grid, are ideal for applications requiring high efficiency and compatibility with sensitive electronics, such as some modern solar water heater controllers. However, for basic solar water heaters with simple electrical requirements, a MSW inverter can be a cost-effective solution, assuming the system’s components are compatible.
System Design Considerations
When designing a solar water heater system using a MSW inverter, it’s essential to consider the specific requirements of the heating element and any associated control systems. For instance, some solar water heaters may have specific starting current requirements that need to be met by the inverter. System designers should also ensure that the MSW inverter is rated for the system’s maximum power requirements and has adequate surge capacity to handle startup inrush currents.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.