The grid is not ready as it sits today. While the energy increase from EVs will steadily ramp up and existing transmission and generation will handle it over the next few years, distribution is going to be a big problem. Conductors and switches on the distribution system are probably sized ok for a modest increase in usage but substation and distribution transformers are definitely undersized.
As an example, as it sits now a typical suburban tract of homes will have 10 homes on a single 100 kVA pad mounted or subsurface transformer. Today there’s little issue overnight as AC load and other miscellaneous small loads might hit 50 or 60 kVA for all those 10 houses in aggregate so there is no worry about overloading the 100 kVA transformer.
Now fast forward 10-15 years in the future and assume all 10 houses are charging their cars on Level 2 48 A chargers overnight (totally plausible if at some point most will drive EVs and want to charge at home if you have the capability). That is at minimum 115 kVA in aggregate load overnight and if you add the 50 or 60 kVA from AC load during the hotter months then we’re talking 175 kVA load on a 100 kVA rated transformer. First of all, that transformer will fail quickly being overloaded for that many hours every night so a replacement to a bigger transformer would be needed. Now multiply this failing transformer scenario times the thousands of what then will be undersized transformers in the many neighborhoods and tracts in America and you can see that we have quite a bit of work to do.
As an example, as it sits now a typical suburban tract of homes will have 10 homes on a single 100 kVA pad mounted or subsurface transformer. Today there’s little issue overnight as AC load and other miscellaneous small loads might hit 50 or 60 kVA for all those 10 houses in aggregate so there is no worry about overloading the 100 kVA transformer.
Now fast forward 10-15 years in the future and assume all 10 houses are charging their cars on Level 2 48 A chargers overnight (totally plausible if at some point most will drive EVs and want to charge at home if you have the capability). That is at minimum 115 kVA in aggregate load overnight and if you add the 50 or 60 kVA from AC load during the hotter months then we’re talking 175 kVA load on a 100 kVA rated transformer. First of all, that transformer will fail quickly being overloaded for that many hours every night so a replacement to a bigger transformer would be needed. Now multiply this failing transformer scenario times the thousands of what then will be undersized transformers in the many neighborhoods and tracts in America and you can see that we have quite a bit of work to do.