Solar power optimizers
You can’t use electricity directly from solar panels. They produce direct current (DC) electricity, while most appliances run on alternating current (AC). A special box called an inverter is used to convert DC from solar panels to AC.
Some electric power gets lost along the way. And here is why we need power optimizers – they increase efficiency at the point of power generated from the solar modules to compensate for further losses.
How power optimizers work
Let’s dig into some power optimizers theory first. Power optimizers are DC/DC converters. They are installed right on solar panels and turn them into “smart modules”.
When solar panels produce electricity, optimizers take that DC energy, “optimize” its voltage and send it down to the inverter. Important thing to remember: they are not inverters on their own. You need to pair optimizers with a string inverter that takes care of the DC-AC conversion process.
Microinverters vs power optimizers
Not all inverters are string. There are so-called microinverters, which are a kind of a 2 in 1 solution. They invert DC to AC, like string inverters, but are smaller and installed on each panel, like power optimizers.
Both microinverters and optimizers allow monitoring the performance of each individual module. It gives you more detailed information on your system and helps in troubleshooting.
Both of them work perfectly under shaded conditions. Usually, if one panel is underperforming, it will drag down the whole array. With power optimizers or microinverters, you’ll never have such an issue: every panel will work for itself.
Now to the differences:
- Power optimizers tend to cost two or three times less than microinverters.
- A solar PV system with optimizers is harder to scale than with microinverters. With the latter, all you need to do is to buy just another microinverter for an additional panel. With optimizers you’ll have to redesign the whole system, as they are connected to the centralized string inverter.
- Microinverters need some maintenance, but they are unlikely to affect the performance of your system if something goes wrong. If an optimizer fails, it is likely to affect the string inverter while repairs are underway.
How to size power optimizer
Sizing power optimizers are easy: they must match the power rating of your solar panel. For example, if you have 400W solar panels, Solaredge optimizer 400W will work just fine. Keep in mind, that the panel wattage can’t be higher than the power rating of the optimizer. Otherwise it won’t cope with the electricity optimisation.