There are plenty of places in the USA you can get power for less than 10c / KWH.

 There are a few you can get under 5 even as a small miner.

 There are 2 areas you can get under 3 as a "home or VERY small business" miner, and another one next to those at a little over 4.


 That's ALL UP costs - keep in mind that there are some power companies *coughALLIANTcoughENERGYcough* where you end up paying more on the final bill for "surcharges and fees" than you pay on the base rate.


 THe problem with solar energy is 2fold.

 (1) The sun only shines part of the day, you have to have VERY LARGE battery banks OR a "grid tie" arrangement to keep the miners going 24/7
 (2) UP FRONT COST - when you amortise that over the lifetime of the gear, the end result tends to be a VERY VERY HIGH cost per actual killowatt generated.

 Keep in mind the solar panels are rated at their PEAK power output, with a high amount of sunlight feeding into them - their AVERAGE output is quite a bit lower over the course of a day, commonly 30-40% of that peak (less if you don't set them on a tracking mount, more if you do) and then you lose even more on days that are cloudy, rainy, or anything else that obscures the Sun for any part of the day.


 Similar issues apply to Wind power - you're going to get output at night, but even in places with a high "average" wind speed (NW Iowa for example, from personal experience) you still end up with periods of "not enough wind to turn the generator", others of "not enough wind to get full output from the generator", and sometimes "so much wind that the blades have to be feathered or the whole windmill turned out of the wind to avoid damaging or even destroying the blades and little-to-no output from the generator".
 You're not reliant on the sun, but the wind is even LESS predictable and a lot MORE variable on a shorter-term basis.