The claim that multiple EV chargers on a single distribution transformer can reduce its lifespan from 30-40 years to as little as 3 years is alarming.

I think it is important to understand the details of the mechanism - we know for example that extreme thermal cycling can greatly shorten transformer life,

M,

Is there a solution to this ? Replacement  cycles as frequent as every three years are neither economically viable nor operationally sustainable, the carbon footprint associated with manufacturing these transformers probably outweighs the benefit of driving a EV 

Is there a solution to this ? Replacement  cycles as frequent as every three years are neither economically viable nor operationally sustainable, the carbon footprint associated with manufacturing these transformers probably outweighs the benefit of driving a EV 

I'd imagine, as we have no such issue yet reported in the UK, it  is something that depends heavily on the local transformer and network design and/or de-rating practice. The places to watch here will be the new transformers going in at motorway services and so on that are serving almost nothing but car chargers - I'd expect those to be the canaries in the coal mine if there is an issue - but most of those installations will be less than 5 years old at the moment.

Mike.

Raises the question of whether these challenges were thoroughly considered prior to the widespread installation of UK transformers for service stations etc

AMK said:

Is there a solution to this ?

I suspect the main solution is not to under-size the transformers.  You aren't going to get extreme thermal cycling if the transformer is operating within its rating.

So this sort of rapid wear-out over 3 years is on transformers originally installed not designed to handle the continuous high loads or the harmonic content introduced by modern EV chargers.

My local power supplier has a special EV charging deal.

They will install a unique EV charging station at my house for free. if I sign up for $30-$35 per month fee, allowing me (if I had an EV) to charge it at overnight.

No mention was made about having to swap the transformer out.

My current pole transformer also services about 8 other houses.

Peter Brooks Palm Bay Florida USA

Hi Peter. Are you considering going EV ? What are your electricity rates per kWh ? 
- Andrew 

Hello Andrew:

1) Do I plan to get an EV? No way!

2) What are my electricity rates per kWh ?

My monthly charge varies by month - Last month January was relatively cold and we used peak power.

The charge is made up of fuel and non-fuel parts, state taxes, local franchise and Utility taxes.

Lumping everything together for January 2025 it was about US$100  for 638 kWh.

It should be noted that the house is "ALL Electric:- no gas, coal or wood. Heating is with air  based heat pump.

Peter Brooks

Palm Bay Florida  

Thank you for sharing the details of your electrical bill. I thought it would be interesting to compare your US bill to what a typical UK household might pay for electricity. From your figures, US rate of  US$0.1567 per kWh (£0.123) is significantly lower than the UK average of £0.34 per kWh plus we pay a  Standing Charge:0.55p per day. Your usage of 638 kWh is much higher than the UK average. This is likely because your home is all-electric, including heating via a heat pump, whereas many UK homes use gas for heating.

Hello Andrew:

There were a couple of other factors that may be applicable in your calculation:

There was 33 days in our January 2025 power bill.

The lowest outside temperature during the month was about 40 degrees F.

The house is heated inside to at least 78 degrees F.

The house foot print area is about 1900 square feet   

Peter Brooks

Palm Bay FL.

Your home is quite spacious. In the UK, smaller home sizes typically result in lower electricity usage, but significantly higher electricity rates. Its also highly likely your energy bills could see a reduction with The 'drill, baby, drill' approach.