Each of these installations could be paired with charging infrastructure appropriate for the location. Around office buildings where the typical stay is several hours, charges could exist in many or most stalls to charge cars through the work day. Retail where the stay is typically shorter would focus on rapid chargers. Some would focus on those that are shopping, others would replace the gas station on the edge of the lot.
Every sufficiently large building has a loading dock. Those that get regular use with trucks that sit there for a while (trailers loaded and unloaded while the driver waits) could have rapid chargers for trucks.
Some battery capacity would be needed to account for grid limitations in some areas. This would be a great second life for degraded car batteries. If the batteries are near full while the short term expectation is for high generation, the price could drop.
> Retail where the stay is typically shorter would focus on rapid chargers. Some would focus on those that are shopping, others would replace the gas station on the edge of the lot.
L2 chargers is what we desperately need. L3 chargers should be reserved to be built at long range locations.
L2 chargers at a grocery store could give you ~40 miles in an hour. Enough to cover your daily commute.
Put a bunch of L1 chargers in an office garage. They'll do around 4 miles in an hour.
The reason to do it this way is because the same L3 connection doing a single 350kW charger can power ~30 L2 chargers. The circuit doing a single L2 chargers can power 10 L1 connections.
We can reasonably put a slow charger pretty much anywhere someone would park. These slow chargers hardly impact the grid and are cheap to add.
Are L1 vs L2 vs L3 chargers radically different in cost? Or is it that you want to provision charging speed proportional to the power being supplied from solar at the business?
> Are L1 vs L2 vs L3 chargers radically different in cost?
Short answer: yes. L1 to L2 isn't that dramatic - it's typically a 240V 40A separate circuit, which is not something to dick around with lightly but pretty easy stuff for a regular electrician. L2 to L3 is a very different ballgame, involving specialist installers and interacting with the power company to get a fatter circuit. Even a single 100kW charger needs a circuit that would be at the high end of what most people get for their whole house, so for a bank of them you're equivalent to a whole subdivision.
I agree with GP that L2 is the way to go for most parking lots. It's enough to provide more charge than the round trip took for most visitors, and you can have a bunch of them. Also you don't have to deal with different charging standards; J1772 is practically universal. You could put in even more L1, but you'll quite likely to have more than you have customers (at one time) to use them and those customers won't get as much charge back as they consumed for the visit. For something like a corporate campus where people stay all day it makes more sense, and an apartment complex likewise except that you'd need some local storage to "time shift" from the sunny day to the occupied night.
Also, while I'm here, I'll raise another point that I haven't seen mentioned. The shade provided by a parking-lot solar array isn't just a matter of comfort or aesthetics. When it comes to charging EVs, it also allows faster charging and/or can help extend battery life. It's rare to find two technologies that complement each other so well.
Every sufficiently large building has a loading dock. Those that get regular use with trucks that sit there for a while (trailers loaded and unloaded while the driver waits) could have rapid chargers for trucks.
Some battery capacity would be needed to account for grid limitations in some areas. This would be a great second life for degraded car batteries. If the batteries are near full while the short term expectation is for high generation, the price could drop.