I am hoping to have both solar and micro-turbines installed on my house and two-story garage. Being in the northern part of the U.S. keeps the cooling factor down, but we also tend to have a lot of wind. Between the solar and the wind, energy is created constantly, including during the night. The key is storage. Battery storage is getting better with each year.
The initial costs associated with both solar and wind are high, but with the various tax credits, it can actually become quite cheap really. Add to this, spending nothing for normal house current, and it is a winnable scenario.
Using older tech, with high power requirements, is a mathematical challenge really. Unless you have the capacity to add more and more solar panels, storage, and micro-turbines, you run out of electrical capacity quickly with very few units operating. You definitely do not want to go too "old," because power requirements were very outlandish for even 1 or 2 year old equipment. The key is to only purchase that which has the most efficiencies, but is no longer in favour. For scrypt mining, it is a no-brainer really, as Titans are the most efficient still today, and you can run more of them with the amount of energy produced from alternative sources, mountable to residential roofs.
On a related subject, I was surprised to notice that any SHA-256 equipment with the name GAWMiners painted on it, goes for less than its non-rebranded equivalence. Apparently, people who have GAW branded equipment do not want the constant reminder of the BS associated with the company, so they appear to be willing to sell it more cheaply on eBay and other places. It might be that they place a lesser quality value on it. However, since the equipment was only rebranded, it does not mean it is of lesser quality, just that it has a crap name painted on it. Another can of paint can resolve that issue. LOL