How do I choose a solar inverter?

When designing a solar installation, and selecting the inverter, we must consider how much DC power will be produced by the solar array and how much AC power the inverter is able to output (its power rating).

Why does inverter size matter?

1. Introduction: Why Inverter Size Matters An inverter converts DC power (from batteries or solar panels) into AC power (for household appliances). Picking the wrong size can lead to:

Are expensive inverters better?

1. More expensive inverters will tend to have higher conversion efficiency and lower no load draws Watt for Watt compared to similar budget models. 2. Most quality inverters will have low power 'eco' modes, but there are caveats to these modes from what I've heard 3. Higher power inverters tend to have higher no load draw 4.

Why is a high power inverter more efficient?

Higher power inverters tend to have higher no load draw 4. Inverters do not have uniform efficiency across their whole power range (most but not all will be most efficient at or near their limit) 5. No inverter is more efficient than the most efficient inverter, so the more you can run directly from DC the less efficiency penalty you get hit with.

Do inverters use a lot of power?

Generally, yes. Inverters have an idle power usage. A Victron 48/5000 burns 30W just by being powered on. That's 0.72kWh/day or 60Ah of 12V battery capacity - would kill a medium size car battery in 24 hours even if no loads are supplied. The MPP Solar/Growatt units and most all-in-ones are notorious for high idle energy consumption.

Are battery inverters more efficient than PV inverter?

4. Inverters do not have uniform efficiency across their whole power range (most but not all will be most efficient at or near their limit) PV inverters are expected to do their best work near full load, while battery inverters normally run at a fraction of full output.