Which is more efficient, a string inverter, micro-inverter, or optimizer systems?
In a residential situation with no trees and minimal other shading conditions the efficiency tend to line up very close. For example, from our product line-up:
-the SMA, ABB, and Fronius string inverters have 96-97.5% efficiency;
-the Enphase power optimizer are listed at 97%, so together 97%
-the SolarEdge and power optimizer, together, get about 98%;
Taking shading out...there is about 1% difference.
The question becomes ease of installation, cost, and shading. Micro-inverters are great for DIY project, they are just easier to install. String inverters tend to be cheaper, especially on bigger systems.
Some people really like the 25 Year warranty with Enphase vs the (normal) 10 years for string inverter. Or the ancillary aspects, the monitoring system with Enphase Enlighten Manager is a big draw!!! Data is collect from the Gateway and interfaced with a smart app or webpage. The cost changes with system size.
The new HD wave changes the game being much smaller, and showing off with 99% efficiency. It comes with a 12-year warranty. SolarEdge also has built in monitoring and an associated software - StorEdge. The price is lower out right for the inverter but consideration must be given to the cost of the power optimizers; which again increases with system size - more specifically module count.
Strategically the HD Wave and Enphase systems will tend to be price competitive. Enphase microinverters are generally easier to set up, but SolarEdge is a very strong product and the best choice when doing anything larger than 3000W. But this all does come at a higher cost. SMA central inverter is way more cost effective if they want a 3kW+ system. If you are still on the fence keep an eye on our weekly sales it might make the difference!
In high or medium shading situations microinverters or a SolarEdge system will be more efficient and in the long run worth the additional cost.
ABB HV microinverters offer the ability to use the 72 cell modules. As does Darfon G320 and Enphase M250-72cell.
For small commercial projects, anything like 16kW and up, consider switching over to Chint or Fronius for 3 phase inverters.