20 kw per day is huge man.
Hope you will create a topic on that. I want to see this.

Go SOLAR ftw!
Solar is definitely the way to go if you can afford a $30,000 solar system.
Ive been looking into Proof of Stake altcoins like NXT.org. Both systems have their issues but PoS doesnt have the need for massive equipment and power requirements that Proof of Work altcoins need to function. PoS makes more sense to me since people are invested in the currency, not the equipment & power needed to support it.
You might want to commit yourself for a few years down the line before you go about buying a solar system specially for mining.
Wouldn't it be simpler and more economical to simply sell the electricity you generate from solar?
If you invest into solar AND mining equipment, your mining income will have to cover the initial investment and running costs of both. I haven't done any calculations on this, but for me this implies a longer payback period. It's different ofc if you already have either of the 2 systems running.
I'd personally do an analysis for myself about what's better? To invest 30K (today) into solar or buy electricity (today and in the future) for my miners for the same cost for x days/months/years.