Ask HN: Share earnings of electric vehicles chargers: profitability?

Hello everybody, I have a startup idea but I couldn't find any info about the (possible) profitability. The idea is pretty simple: the company decides where to build a charging station for electric vehicles and anyone can contribute to installation costs for a fraction of it (e.g. Joe pays 5% of total, Hannah 2%, etc.). We take care of the installation process and routine maintenance and we get a small percentage of earnings, for instance 8%, while the remaining 92% is going to be split proportionally among the "investors" of the crowdfunding campaign (so Joe will get 5% and Hannah 2%). I'm planning to use only 150+ kW DC chargers (ideally, they should be 300 kW to be future-proof).

Do you know what's the average margin per kWh of a charging station like that (it doesn't matter in Europe or America, I'm ready to move if necessary)?

PS: Any tips or suggestions are welcome.

If you are wondering, that 8% doesn't come from any calculation, it's just to explain better how it would work.