johnrhansen said:
so if you owned a business and wanted to provide charging for your customers, what would you rather install. 2 chargers that are good for 20KW, or one good for 40 to 50 thinking the cost to install the 2 20s is nearly the same as the big boy.
Part of the answer depends on the business and location. Are the customers passing through, staying for <1Hr, or staying for >1Hr?
Operating costs can be a big concern. Utilities often tack on a substantial demand charge for exceeding some threshold of demand.
A 50kW charger used one time a month can double your electricity bill, even though the change to average monthly consumption may not be detectable. This alone suggests 20kW chargers cost less to operate than 50kW chargers. Start with a single 20kW, then add or upgrade to 50's if there is sufficient demand.
Install first L3 charger such that any of two (or more) parked cars could use the charger. This allows a second customer to arrive and unplug an unattended fully charged vehicle, and use the charger. Plan for a second charger (similar parking), but install later. Place chargers near entrance, but not in front (this leads to ICEd chargers = access to charger blocked by Internal Combustion Engine vehicles).
Expect that users may not be coming to your business.
Treat the charger as a service to sell on it's own. Set billing rates that allow the charger to pay for itself.
Don't try to restrict use to only YOUR customers, or only during business hours. These chargers are considered undependable - and speak loudly towards your business. Word gets around (see plugshare.com). EV drivers will be going elsewhere to a charger they reasonably expect they can use when they need it.
You might offer free/reduced billing to your customers. Equivalents to carwash codes and loyalty card points come to mind. Easy to do since, on average, electricity is very low cost (subject to meeting demand charges.)
Find a management company that will operate and maintain the charger, but allow you to set terms (you get all the income, they get paid flat rate each month, you get billed for maint/repairs as required.)
Movie theater: L2
Nice restaurant: L2, 20kW
Fast food: 20kW
Shopping mall: L2, 20kW
Coffee shop: 20kW
Just off interstate freeway(s): 50kW (plan for multiple 50kW)
Truck stop: 50kW (plan for multiple 50kW)
Gas station: 50kW (billing like pay-at-pump with credit/debit or by cashier)
Convenience market (example 7-11): 50kW (billing like pay-at-pump with credit/debit or by cashier)