If i understand the article correctly, it's illegal when you wire it to the grid. So, powertools and a battery will be fine. i suppose you could have a big switch outside your house that lets you pick local generation or grid generation, ala a datacenter failover switch.

But nobody wants that. Really, i don't think many people care about selling the power back either. But they've made it already, why waste it? What people want is i'll make the first 5 kwh, and i want to buy any extra from the grid. And i don't want a big switch system for each light in my house. Which seems very normal and sane.