I doubt that planning for 500 charging spaces, each with a loading of 100Kw, at one supermarket is realistic.

A large supermarket near me only has about 300 spaces in total.

To suggest an increase of over 50% in parking provision, AND that EVERY space will have a fully loaded 100Kw charger is very OTT.


A more realistic provision might be 10 fast chargers each of 100KW and a similar number of 7Kw chargers, and a few 2.5Kw charging places. With a bit of diversity, that should be achievable at LV from a dedicated substation near the load. Charge controllers are already available that link together a number of chargers and slightly delay charging or slightly slow the charging rate when needed to avoid overloading the supply.

With such automatic control, I suspect that at least 25 chargers each of 100Kw could be connected to a nominal 1Mw supply. Remember that with 25 charging spaces, that a couple will be taken by vehicles not yet charging (owner still parking, and looking for their payment card) Others will taken by vehicles that are charged but not yet removed because the owner is still shopping. And a lot charging at less than 100KW because they are smaller vehicles, or are nearly full.

The limiting factor is likely to be heating of the 11Kv transformer, so in cooler weather a total loading of 1,200Kw should be fine, and in sunlight an extra 200Kw could be available by PV modules over the parking areas.

Automatic load control, though needed to avoid breaking anything, would very seldom actually operate.

I doubt that planning for 500 charging spaces, each with a loading of 100Kw, at one supermarket is realistic.

A large supermarket near me only has about 300 spaces in total.

To suggest an increase of over 50% in parking provision, AND that EVERY space will have a fully loaded 100Kw charger is very OTT.


A more realistic provision might be 10 fast chargers each of 100KW and a similar number of 7Kw chargers, and a few 2.5Kw charging places. With a bit of diversity, that should be achievable at LV from a dedicated substation near the load. Charge controllers are already available that link together a number of chargers and slightly delay charging or slightly slow the charging rate when needed to avoid overloading the supply.

With such automatic control, I suspect that at least 25 chargers each of 100Kw could be connected to a nominal 1Mw supply. Remember that with 25 charging spaces, that a couple will be taken by vehicles not yet charging (owner still parking, and looking for their payment card) Others will taken by vehicles that are charged but not yet removed because the owner is still shopping. And a lot charging at less than 100KW because they are smaller vehicles, or are nearly full.

The limiting factor is likely to be heating of the 11Kv transformer, so in cooler weather a total loading of 1,200Kw should be fine, and in sunlight an extra 200Kw could be available by PV modules over the parking areas.

Automatic load control, though needed to avoid breaking anything, would very seldom actually operate.