So, in the beginning, I started to search of places, where I use electricity for heating, just simple heating, nothing fancy and I remembered right away one place - the basement!
For years I heated my basement this fine electric heater
I don't even remember how old it is ... anyway, it's time for retiring it.
Next step was to find a new "heater", I need to build something that heats up at least the same power level as the previous heater and costs less 10€. The old heater was 1KW running with term switch, so I decided to build two 400w "heaters". Two single GPU (graphics card) "heaters", as I wanted to keep investing as low as possible, also ... the computers were found from scrap, some very first AMD motherboards with PCI-E slots, graphics cards were found from an old friend, who doesn't need them anymore, as they took too much power - AMD Radeon HD5970.
Some next steps where simple, just put GPU-s into computers, made some soldering and power all up.
Then I decided to use Windows 7 as a platform into the beginning (also computers had the license for it), for installing all drivers into place and mining software into running took some time and skills, not too much but it's not just plug and play. Lucky me, all miners are usually very friendly and I got big help from the start.
After getting computer up and mining software running, I decided to mine Moneros as it looked for me most profitable.
I was so exited of my project so I forget to mark up an exact date for powering up miners, but those two were up to the beginning of Oct to April 6, 2018 (day for Monero fork) as a total reward had 0.72 XMR
As long as basement has separate electric meter, so total electric costs for the period including light is 378€
So ... if the cryptos are really soo bad as they said, I should be made soo much damage, but the power I used was considered "loss" anyway, now I got little more out of it.
So was it profitable? Of course not ... but lots of fun and also ... 0.72 Monero I got too ... maybe I'm HODL it.
We may always argue has it any point to spending any effort to cryptos, but I've to say, if I had used the miner for years to heat up the basement, I'd be better off for now.