There are a lot of GPU mineable coins, you will need to look for the ones which are ASIC resistant so you won't be forced to compete with ASICs when mining with GPUs. If I had some mining rigs I would mine Monero, maybe some ZCash too.

Regarding Dash: 1 Dash masternode is, at current price, $112K and it will bring you $624 / month according to https://masternodes.online/currencies/DASH/

0xcosmos already answered you (missed his reply).


Of course you can mine ethereum, but note that ETH will move to PoS (at least this is what they hope) and you won't be able to PoW mine Ethereum anymore. As a backup you should look after some other GPU mineable coins that are worth mining.

EDIT

Like adaseb said mining is not that profitable if you put your money in the solar array and mining equipment. It will take years to recover your investment.

As an alternative, you can buy and hold Bitcoin - since the price will only increase with time.
Or if you want to have a weekly/monthly income, you can buy 1 or 2 Dash masternodes. (I don't know how much the 1.5 solar array costs but I assume is a lot of money, that's why I said 2 Dash masternodes).

Tip: These 2 alternatives will give you less headaches.

Well,.. with $100K you can buy 122 Antminers T17 which will give you ~61000 Th/s.
With free energy this can be translated into $905/day acording to whattomine.com at current Bitcoin price of $8650.

Keep in mind that Bitcoin halving is near and this will translate into half of that after May 2020.

Since the halving is near, you can look at coins that already had it's halving i.e. Litecoin.

If you don't want to put a lot of money into mining equipment, then search for coins that are ASIC resistent like Monero, Vertcoin, etc.

Buy 1-2 rigs in the beginning and then with the profit you'll make, add more with time. Since you will have free electricity you make profit on most of the coins you'll mine, like ZombieWorm said. Reinvest your profit until you are pleased with how much money you earn per month selling what you mine.

This is the approach I would try if I had free electricity.

Hi guru2class!
First I want to let you know that I appreciate your effort in educate other people about crypto and how to build new cryptocurrencies/blockchains.
One suggestion is that you can try to make your videos to have a better quality, for example: "Learn How to Create Cryptocurrency Like Bitcoin(SHA256)" hurt my ears in the beginning and my eyes all the way I watched it.
I hope you'll take this as a constructive criticism and not as an insult or anything like this. Anyway keep doing what you started eventually you'll get better and better. I wish you all the best and I hope your channel will be successful.