Plug and play: Quick start with AC solar panels

When it comes to production, string inverters and microinverters are both very efficient – microinverters might have a slight edge with 5% more efficiency on average. But it is their ability to cope with shading that makes a huge difference.

Shading is a great hurdle for string inverters. Every module in the string looks up to the worst one. It means that if one panel is under the shade, the performance of every module in the string drops. Usually, to minimize the effect of shading on the string, solar owners have to connect panels in parallel, or add power optimizers to the system.

With AC modules, you won't have such a problem. Panels operate individually – each one has its own inverter. Sure, if one panel is in shade, its performance decreases, but it doesn't affect the other unshaded AC panels. Likewise, if one panel malfunctions, others don't suffer from it. Normally, you can monitor the state and performance of each AC module through your smartphone.

AC solar panels can be considered plug and play modules. After you've set them up, the electricity they generate is ready for the needs of your home, shop or an office. In a standard system, panels have to be hooked up with an inverter, which has to be connected to a commercial grid via an electrical panel. With microinverters you have less wiring to do – all the AC wires just go directly to your main panel. From there, electricity flows to appliances or into the grid.

The fact that you don't have to buy a standalone inverter is great in many ways:

• Save time on choosing and sizing a string inverter.
  
• Save space which can be limited on a boat or an RV.
  
• Save money, as the inverter is the most vulnerable part of a solar installation and you're likely to replace it at least once during the lifespan of your system.
  

Microinverters have basically the same longevity as solar panels themselves. As a result, the warranties for AC modules are usually issued for 25 years. Once you've bought an AC panel, you won't have to worry about replacing an inverter in it. Just unless something goes wrong.

The next question would be: "What can go wrong?" The downside of AC modules is the fact that all the inverters are on the roof and subjected to weather changes. Instead of one inverter, you have several, and if one of them breaks down, it is troublesome to climb the roof and fix it. Microinverters are sturdy, but if extreme weather conditions are common in your area, a rooftop system out of AC modules might not be a good idea.

What is more, AC modules usually end up being more expensive than standard panels plus an inverter. An installation out of AC panels can cost around 20-30% more than a traditional system. However, we've already mentioned that you are likely to replace your string inverter halfway through the lifetime of the panels, so the costs balance out in the end.

Finally, AC solar panels are problematic to use in hybrid and off-grid systems, because solar batteries are usually charged with direct current. If you need energy storage with these modules, you can find AC batteries on the market. They are easy to install, but are slightly less efficient than standard DC ones.

Is it worth installing AC modules after all? If you aren't afraid of spending a little extra, AC panels certainly can make your solar experience smoother and easier. They are perfectly suitable for your home, RV or a boat. Systems made of AC panels are easily expandable: you can add panels one at a time whenever you need more energy. If weather conditions in your area are tame, there is a good chance that you won't have any troubles with an AC solar system for the whole 25 years.