There are three kinds of inverters: string inverters, microinverters, and power optimizers. They all transform the power your solar panels generate from direct current (DC) to alternating current (AC). This makes the energy usable for your home. Do you know what to look while shopping inverters?
No matter which type of inverter you choose, there are three major considerations: warranties, operating temperature range, and efficiency.
Here’s a breakdown of what to look for in a solar inverter. We’ll also look at these with the top three brands selected through the Pick My Solar Platform in 2017.
What to Look for In An Inverter – Warranties
Most people feel more comfortable purchasing electronic devices with warranties. Solar inverters are no exception. Most inverters have warranties ranging from anywhere between 5 and 10 years, though some can be extended to 25 years.
When you’re looking at a company, make sure you know what’s included in the warranty and what’s not. For example, some power optimizers might not include the central inverter under the warranty.
Also make sure you understand the terms of a warranty. Is the device covered in case of an internal glitch as well as in the case of external damage? Will you be charged for labor or shipping if you have to send parts in? These are all important questions to ask.
What to Look for In An Inverter – Operating Temperatures
As with most electronic equipment, inverters operate best when they’re running cool. Operating temperature is the safest temperature range an inverter maintains.
Inverters will naturally generate some heat themselves as they do their job. Since they’re typically in an uncontrollable environment outdoors, they’re exposed to a wide range of temperature fluctuations.
Obviously, conditions aren’t always ideal and some times an inverter will have to work harder than others. The higher the operating temperature (the more heat it can handle), the better.
What to Look for In An Inverter – Efficiency
There are two numbers to look for in solar inverter efficiency: peak efficiency and weighted efficiency.
Peak efficiency will give you the efficiency of your inverter when it’s running optimally. It’s good to know what the best-case scenario is, but it’s also worth noting that it won’t always be hitting that level. Some days it might only reach peak efficiency for an hour or two, or maybe not at all.
Weighted efficiency figures in the variables like DC input levels. This gives a more accurate gauge as sunshine, temperature, and other environmental elements affect inverter efficiency throughout the day.
How do the top three inverters stack up against the parameters we just reviewed?
1. SolarEdge was the most popular through the Pick My Solar platform last year at 72 percent.
- Warranties: 12 to 25 years
- Operating Temperatures: -13 to +140C / -25 to +60F
- Best Peak Efficiency: 99%
- Weighted Efficiency: 97.5% to 99%
Read more specs on SolarEdge inverters here.
2. Enphase was another favorite, winning 21 percent of the projects through our platform.
- Warranties: 25 years
- Operating Temperatures: -40 to +65C / -72 to +117F
- Best Peak Efficiency: 97.6%
- Weighted Efficiency: 94.5% to 97%
Read more specs for Enphase microinverters.
3. SunPower was not to be overlooked as the third most selected inverter, coming in at 6 percent.
- Warranties: 25 years
- Operating Temperatures: -40 to +85C / -85 to 185F
- Best Peak Efficiency: 98%
- Weighted Efficiency: 95.5% to 98%
Read more specs for SunPower’s microinverters.
You can see more details and inverter specs on the downloadable spreadsheet form the Go Solar California list of inverters.