Midas,I had a stab at it, but to be honest I wasn't 100% sure...

Midas,

I had a stab at it, but to be honest I wasn't 100% sure the way I was doing it was correct.
Will outline it for you to have a look over.

Prices are charged in kwh (kilowatt hours).
4Mw generator peak output is 4000Kw .
Vanuatu price per kwh are pretty steep, up to US60c per Kwh, as electricty is generated using diesel generators.
Decided to use US20c per Kwh instead of the peak oil price value.
So max possible income assuming 24hrs at full use is
4000*20*24 = US$19,200 per day
= US$7,008,000 pa(full 365 days)