There seems to be a standard installation developing for domestic EV charge points where it is 6mm2 no matter what. I checked one installation which will have around 9v dropped on a 7Kw charger. Ok, I acknowledge that the full load current won’t be pulled at all times but it can be assumed that there will be long periods when it will. Multiply that by an ever increasing demand across the nation and we can expect to see considerable energy wastage. Perhaps, we should be setting tighter limits than 5%.
I agree, this could be a major issue. Whilst the equipment might work fine on lower voltages there will be extended periods of charging at full power. Apart from the cost of the losses, figures like 5% are more than half of the transmission and distribution network losses combined (say circa 8-9% for domestic use). All this power has to be generated and at times when the system is stretched the marginal costs can be considerable (last week IIRC system costs exceeded £1000/MWh (i.e. £1.00 a kWh) and these costs end up in consumer prices sooner or later. If losses could be kept down this would reduce bills directly and indirectly by reducing the marginal costs of generation.
There is some interesting work led by Imperial College on the network losses in the service cables that connect homes to the main in the street that shows that these comparatively short cables are responsible for a surprising proportion of system losses and I dare say equivalent arguments apply to the cables feeding EV charging points. This work predates EV charging which will aggravate the issue so overall there is a lot at stake. I hope that the DNOs are considering service cable losses as part of their net zero planning.
I agree, this could be a major issue. Whilst the equipment might work fine on lower voltages there will be extended periods of charging at full power. Apart from the cost of the losses, figures like 5% are more than half of the transmission and distribution network losses combined (say circa 8-9% for domestic use). All this power has to be generated and at times when the system is stretched the marginal costs can be considerable (last week IIRC system costs exceeded £1000/MWh (i.e. £1.00 a kWh) and these costs end up in consumer prices sooner or later. If losses could be kept down this would reduce bills directly and indirectly by reducing the marginal costs of generation.
There is some interesting work led by Imperial College on the network losses in the service cables that connect homes to the main in the street that shows that these comparatively short cables are responsible for a surprising proportion of system losses and I dare say equivalent arguments apply to the cables feeding EV charging points. This work predates EV charging which will aggravate the issue so overall there is a lot at stake. I hope that the DNOs are considering service cable losses as part of their net zero planning.
