"Setting aside the positives of the axial flow, you electrical engineers, is this power possibly of the quality they are saying???"
I'm not an electrical engineer, just a wind mechanic with a fair amount of experience with small induction gridtie machines. The quality of the power is exactly what the utility supplies.
These are induction grid tie machines- pretty simple in concept, but as usual, the devil is in the details.
The Prairie machines haven't been around long enough to work out any possible structural problems. For instance, they use a welded rotor plate that looks like fatigue failure waiting to happen and have no overspeed control on the rotor. It seems like a small thing, but for power outages, gearbox, generator and control failures, overspeed control is critical. Yeah, most of the time there won't be a problem, but it only takes one shutdown failure in a high wind to make a pile of junk out of an almost perfectly good wind turbine.
$.026/kWh is a tough rate to try to break even. Wind farm operators don't even try to make money at that rate, and they have a tremendous economy of scale advantage over small machines.
Your RECs attitude towards interties can be a big factor, too. South Dakota doesn't have a net metering law or interconnection standards so the utility can, under federal law, legally demand expensive under/over frequency and voltage intertie and power outage protection, can charge to install separate meters for use and production and charge a monthly fee for their use! Maybe it's not a problem, but check first. A hostile utility is a killer for small wind interties. Google "South Dakota""net metering" for more info.
If you do decide to go ahead with it, there are similar used Enertech machines out there - 4kW and 5kW- that would be a lot cheaper and with a pretty good structural history.
The big plus in your situation is that you've got a great wind site and you should be able to get good production from your turbine. (I'm envious!)
Neil
Neil