100W continuous at 12¢/kWh (US average) is only ~$9 / month. Is your electricity 5x more expensive than the US average?
$50/month for 100W continuous usage isn't totally mad, and that could climb even higher over the rest of the decade.
Still only $50/month, not $150, but I very much care about 100W loads doing no work.
That said, I am not sure those numbers are true. I am in California (PG&E with East Bay community generation), and my TOU rates are much lower than those.
Minimum Delivery Charge (what’s paid monthly, which is largely irrelevant, before annual true-up of NEM charges): $11.69/month
Actual charges, billed annually, per kWh:
Peak NEM charge: $.62277
Off-Peak NEM charges: $.31026
Those rates do get a little lower in the winter (.30 to .48), and of course the very high rates benefit me when I generate more energy than I consume (which only happens when I’m on vacation). But the marginal all-in costs are just very high.
That’s NEM2 + TOU-EV2A, specifically.
I can solve for them with three equations for three unknowns... but since they change the rates quarterly by the time I know what my exact rates were they have changed.