Where I live prices are often higher than 20c/kWh, but lets take your example and halve it (10c/kWh) so it's ~$1.40/day or ~$500/year.
On Openrouter, the cheapest GLM 5.2 provider costs $3/MTok (at 44 tps). Assuming most use is output tokens, that's still the equivalent of 450k token/day, so we're in the same ball park, but without the capex for 2 3090's and the machine.
Self hosted only makes economic sense if your priority is being in control / avoiding surveillance.
That's true, there's a lot of places where power is considerably more expensive than $0.20 USD/kWh. But also the 600W figure assumes that it's fully loaded 24x7x365.
Running a system that will be 600W under max CPU usage on all cores and RAM and a few 3090-class GPUs, that same system might be only 90W or around there when idle at 0.00 unix load.
If we say: (600 * 24 * 31)/1000 = 446kWh in a month at full load 24 hours a day
But it could be less, such as: (90 * 12 * 31)/1000 = 33.48 kWh of idle time in a month, and 223kWh of "full load" 600W time in a month, if it's at full load only 12 hours a day.
If you're the only user accessing it and you only "use" it 12 hours a day, that cumulative yearly dollar figure would be almost halved. Or even less if a person is using it in bursts and intermittently throughout an 8 hour workday.
The usage is irrelevant if we're interested in cost per token. If you use it half as much, you get half as many tokens at half the cost. It's still $5.56 in electricity per million output tokens either way (using $0.20/kWh, adjust accordingly if you have cheaper electricity). If you use the API, you also pay half as much if you use half as much.
> person is using it in bursts and intermittently throughout an 8 hour workday.
You can’t do that with 6 tps, though.
I think that's the biggest difference for most. If you can amortize the hardware costs, then 'burst usage' is cheaper at home to a degree, because you are paying a fixed monthly rate elsewise. Overall thought for most, it is likely cheaper to use the cloud than at home, but really depends on what you want.
> because you are paying a fixed monthly rate elsewise
No, you would pay usage based rates with API, in this case. I have exactly one fixed monthly rate for the 6 AI models I have tokens available for.
> But also the 600W figure assumes that it's fully loaded 24x7x365.
It isn't 100% efficient. Even the best PSUs aren't.