Modern heat pumps provide a lot more than 100% efficiency. I'd stick to the heating system unless those containers are doing something profitable (mining?)
Literally nothing provides 100% efficiency. You're conflating coefficient of performance with efficiency. They're not even close to the same thing, modern heat pumps reach their CoP because they don't actually generate heat, they simply move it around, which provides more heat indoors than if you had converted an equivalent amount of electricity directly into 100% heat.
Thermodynamics would not take kindly to you having a >99.999...% efficient anything.
> because they don't actually generate heat
Heatpumps still do use electricity(or other power), and all that electricity also ends up as heat. It's why heatpumps have higher CoP than the same system as a refrigeration cycle.
> Thermodynamics would not take kindly to you having a >99.999...% efficient anything
Well the cogen gas powerplants here can produce 50kWh of electricity from burning 100kWh of natural gas. I can use 50kWh of electricity to put 200kWh of heat into my house with a heatpump.
Seems like a good deal to me, and I think carnot would be fine with that.
Thermodynamics would not take kindly to you having a >99.999...% efficient anything.