The brains of plug-in solar is the microinverter. Adrian Kingsley-Hughes/ZDNET Follow ZDNET:  Add us as a preferred source  on Google. ZDNET's key takeaways Plug-in solar uses microinverters to feed power into a household system. So far, in the US, only Utah has passed legislation to allow such systems. These systems cost about $2,400 and will take years to pay off. Ever since handling my first tiny solar panel quite a few decades ago, I've been fascinated by them. The fact that a bit of glass had the ability to harvest power from a big nuclear orb 93 million miles away blew my mind back then, and continues to blow my mind now. Since then, solar panels have grown in size and efficiency and dropped in cost to the point where it's becoming economically feasible for you and me to buy panels and generate our own electricity. But what do you do with that power? Also: I've tested dozens of power stations - here's how I'm preparing for summer blackouts Up until now, you've had two options.…