Best practices for calculating inverter needs for a tiny house?

Determining Total Wattage Requirements

To calculate the total wattage requirements for your tiny house, gather the wattage ratings of all appliances, including lights, refrigerators, and water pumps. Add up these values to determine the total wattage required. For example, if you have a 100-watt refrigerator, a 20-watt water pump, and 8 lights with an average power consumption of 9 watts each, your total wattage requirement would be 100 + 20 + (8 x 9) = 145 watts.

Considering Peak Sun Hours and Battery Capacity

Peak sun hours (PSH) are a crucial factor in determining inverter size, as they directly impact the amount of power available from your solar array. Assuming 6 hours of PSH per day, and using a 4 kW solar array, you can calculate the maximum power available to the inverter. If you also have a 12V 100Ah battery bank, consider a charging efficiency of 90% and a discharge depth of 50% to determine the maximum available power.

Selecting the Right Inverter

Based on your total wattage requirements, peak sun hours, and battery capacity, select an inverter that meets or exceeds these specifications. Consider factors such as efficiency, redundancy, and compatibility with your existing solar array and battery bank. For example, if you need 2 kW of power, consider an inverter with a 2.5 kW capacity to account for power fluctuations and efficiency losses. Be sure to also check the inverter’s DC input voltage range, AC output voltage, and frequency compatibility to ensure seamless integration with your solar array and electrical system.