I don’t actually grasp how this thing is beneficial. Could someone explain it in a few simple sentences?
His three-thousand-watt prototype, on the other hand, is more than five times the size and much more difficult for a single person to lift.
Look at it from a personal power production perspective to reduce how much power a person (or family) has to buy from the grid. That's what to think about when you see that it's about micro wind turbines (or micro water turbines, or residential solar). Another word to look for in this concept is "decentralized" as in "decentralized solar" like some of us FReepers with solar have to reduce how much power we buy from the grid to reduce how much the Dim's stupid energy policies impact our wallets. It's not about saving the world our powering the grid with so-called "clean energy". Devices like these don't put power onto the grid. This is about increasing a person's self-reliance.
And about what makes his invention special is, ostensibly, it handles wind gusts better. When the turbine creates power based on the expected wind speed for the area, the charge controller taking in that power isn't maxed out. But with excessive wind speeds a fixed propeller will generated more power than the charge controller can take in. So this guy (and the makers of the large scale wind turbines for grid power) try to account for that by having the wind turbines' propellers automatically change shape to reduce how fast the wind turns them when wind speeds exceed the usual amount. As to why that's the approach instead of just making the charge controller able to take more power anyway, I don't know. Maybe that'd be infeasible to do. (See my post # 10 on how we handle a similar problem with decentralized solar in a way that IMHO is cheap and doesn't add maintenance.)