There is a bit of terminology confusion in the thread. Anyway - an ETH-mining GPU (I will take my current GPU as an example, tho I don't mine) consumes 250 W/h. That's 6 kW a day. At the rate of $0.3/kW that's $1.8. Looking at the mining rate for this GPU and the current ETH price, it can mine about $2/day. So the profit is $0.2 per day. Considering that the GPU costs about $600-$700, it will take 8-9 years to pay for itself. 3-4 years if you're paying $0.09/kw like I do. And that's if the difficulty doesn't increase
I guess you'd need an ASIC to get decent results but that would be an even bigger up-front cost. Whatever hardware you buy probably only has a couple of years or so of productive life.
Urgh also wrong. Appliances are rated in watts. If you run a 3000 watt kettle for an hour you have used 3 kWh of energy. If you run a 3000 watt kettle for 1 minute you have used 0.5 kWh of energy.
Yes - the confusion is yours. Your terminology is wrong, as are your calculations. A $700 GPU (such as nvidia 3060) will have gross profit of $2.06 with elecricity costs of $0.23/day, so just over a year. However, Ethereum won't be mineable by GPU late 2021 or early 2022, so there's no guarantee you'll ever pay it off just mining. Mining rates are affected by desktop use too - so will be 20-30% lower when using your PC.
0.05kWh I re-read your original reply and you were correct. What threw me was I'd been previously reading about rigs consuming around 3kW, so when I saw your figure of 2.8 I just assumed that was the rating. Now I get it that you were referring to a graphics card consuming 116W.
Before starting to think about heating your house for free and mining at the same time, it can be useful to start first with a basic course of math. I invested the same budget in daytrading. There are days that I make more profit than my annual heating bill. I don't have the problem of BTC prices crashing and making mining a losing job. Don't have a rig that is running day and night.
Not that I'm interested in mining but the mining rigs advertised on the link the OP provided are 3X more expensive than what the company that makes them asks for them.
$0.23/day for NVidia 3060 assumes $0.06/kW cost of energy. I am not sure where you live to get that low a rate.
The energy calculation sums continue to be poor on this forum. The sums are based upon $0.09/kWh. Nvidia 3060, when mining, consumes 106.25 W of electricity. 106.25W over 24 hours is 2.55kWh. 2.55 kWh of electricity per day. 2.55 * $0.09/kWh = $0.23 per day. The $0.09/kWh rate came from previous poster. It's significantly more in most places.
If you can't work out the maths yourself, another site that does a good job of this is here: https://whattomine.com/ FYI, I have 27 graphics cards mining for a bit of fun because I'm a geek at heart. Not really looking to make anything out of it, but I've got a crazy machine learning rig when it all comes crashing down.