You have: 40 MWh
You want: tonoil
* 3.4393809
/ 0.29075
You have: 1 tonoil
You want: barreloil
* 6.8419323
/ 0.14615754
You have: 6.84 barrel
You want: liter
* 1087.4731
/ 0.00091956298
So, roughly 1,100 litres of oil per 40 MWh(thermal).
The generator is likely ~30% efficient at converting heat to eletricity, so bump that up to 3,700 litres/hour.
Even allowing for other inefficiencies, 12,000 litre/hr seems high to me. Though as a practical measure it may be correct. It's within a factor of 4 of the actual demand though.
GNU Units has builtins for some standard energy equivalent units, specifically "tonoil" and "barreloil". "litreoil" doesn't seem to be included by default (though it can be added via a local configuration file).
literoil = 1 barreloil * liter/barrel
And the calculation gives me ...10.69 kWh/L
The barreloil value is for crude, diesel may have a slightly higher net energy density. But we're good to 3 sig figs.
I could have bypassed the tonoil step and calculated thermal energy in barreloil directly though saving another conversion.
Otherwise I'd have to remember energy density/L of diesel fuel.
I've added the definitions for litre, pound, and kg oil and can now run:
$ units --terse '40 MWh/30%' literoil
12470.969
The fun part though, at least for me, is showing how to do conversions with GNU units, and the equivalences which become apparent doing so.
You have: 40 MWh
You want: tonoil
* 3.4393809
/ 0.29075
You have: 3.439 tonoil
You want: barreloil
* 23.529405
/ 0.042500012
You have: 23.529 barrel
You want: liter
* 3740.8121
/ 0.00026732164
You have: 3740/30%
You want:
Definition: 12466.667
Or a bit above 12,000 litres. Article was correct.
The generator is likely ~30% efficient at converting heat to eletricity, so bump that up to 3,700 litres/hour.
Even allowing for other inefficiencies, 12,000 litre/hr seems high to me. Though as a practical measure it may be correct. It's within a factor of 4 of the actual demand though.
(Calculations using GNU units.)