Thank you again for your great post.
I came up with a similar result - except the price I would be selling electricity. The price of petrol in the Nullarbor desert has been in the range $2.50-$3.00 per litre. I reasoned that if the electricity is sold at a price corresponding to say 70-80% of what an ICE would need - so I chose $1.80 per kWh. (Actually the 250 cars/day relates to Nullarbor, not Simpson, however the calcs are the same). Today's price of 91 ULP is $2.85
https://petrolspy.com.au/map/station/5212b32e036441297fdbf242Yes that is much more than in the city, and people would grumble, but they are in the middle of nowhere, and still paying less than petrol. Most people would cross a desert very few times in a lifetime, so a once-only premium for the adventure is reasonable.
So, at that price, the yearly gross return would aporoach 100% - a great investment opportunity.
One reason why I did this calc is that someone said that EVs will never be able to cross the Nullarbor.
Another is that I am a landlord for a petrol station at the edge of a city. So far EVs have not affected volume of sales, but I expect that to reduce to 50% in 10 years. What then? I suspect many petrol stations will disappear, as most people will charge at home. Those who can't charge at home are the travellers, taxis, trucks and those who live in apartment buildings, (like me - as the cost to upgrade the supply into the building is prohibitive - hence why I don't have an EV yet).
A problem with service stations is that they contaminate the land. I could turn my service station site into residential or commercial use, but to decontaminate the land takes several years, plus the build time, during which I would lose rent. I still haven't figured out my next move.
Anyway, one advantage of solar field +batteries vs petrol pumps and underground tanks for 4 different types of fuels, is that it can be built up in stages say 10-20% of final capacity each year, whereas the tanks go in once and that's it.
Also I thought this scenario would apply along all highways - and as you said there is no need to upgrade the grid -actually the opposite applies - since the solar panels are cheaper than the batteries one could set up a larger field and sell the extra into the grid.
(20min delay)