For the past several years, this annualizes to about three weeks of free winter heating (via bespoke XMR). I mine solo, but I imagine if you "pooled" it would be similar incomestream (but more reliable). I have had a year of "no winnings," but I persist with the odds to warm myself and the network.
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Half of my kilohashing runs on obsolete i5 equipment (==free-to-me, minus geektime) – Monero Foundation strives to operate with GPU- & ASIC- –resistance; processors haven't gotten that much faster (in the past decade), and a surplus i5 isn't that much slower than a new $500 Ryzen (~2/3rds hashrate).
Monero's Windows7 client still works (fully supported), so perhaps you now have a use for your dusty-old laptop?
Should you need to upgrade the hard drive (mining currently requires full-blockchain, which is ~300GB and growing), you might as well experience linux (installing UbuntuOS is easy once you've created the USBmedia).
It is definitely not worth purchasing additional equipment, with residential rates, just to mine monero. I like warm toes, and have lots of spare CPU cores.
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Reminder: this is only "free electricity" if you're offsetting RESISTIVE HEATING (i.e. not a heatpump). To actually reduce your powerbill and save the planet (the smarter choice), you should install a heatpump for wintertime heating.
This isn't a "guaranteed moneymaker," it's to heat your geeky underdesk toes – you are just making a fancier resistive spaceheater, which occassionally pays for itself.