The standard supply for a new house seems to be circa 18KVA single-phase. I have a client who needs to make application for a supply for a new build house at 400m2 with the only certain information being that an air source heat pump is to be used for heating. The client simply does not know what the electrical loading might be. The house is only coming out of the foundations but the DNO supply may take many months as the house is in a relatively remote rural location, thus loading details are required before the DNO will consider progressing the proposal. It is a big house, but that is what it is, just a big house. I am inclined to advise a standard supply but 3-phase as with a large AS heat pump, maybe shower, cooking and perhaps an EV or two, 18KVA wouldn't be long being gobbled up. As we move towards a higher reliance on electric as a power source for some heavy current-using equipment, it might be that 18KVA is no longer a realistic standard supply for even the smaller property.
Even a 3 phase 100 amp supply might be marginal with a couple of 22Kw vehicle chargers. ...
I am pretty sure that the DNO will not contract to supply 69 kVA. I am not quite sure how ADMD is applied to a single property, but I got 30 kVA.
More than one 22 kW charger seems silly. That's about 80 - 100 "mph" so unless somebody is spending several hours per day behind the wheel, that sort of power is just not needed. Even with a 100 mile round-trip commute (and no charging at work), each car would only be charging for an hour a day. One will do with perhaps a second 7 kW charger so two vehicles may be charged simultaneously.
I am sure that diversity will take care of things, but let's suppose that it doesn't. If the occupier is out for 8 hours per day and asleep for another 8, the only substantial use will be for 8 hours. Let's say that an average of 50 A per phase is consumed. That is 50 x 3 x 8 x 0.23 = 276 kWh per day. Let's assume a tariff of £0.15 per kWh. That comes to £41.40 per day or £15k per year!!!
Even a 3 phase 100 amp supply might be marginal with a couple of 22Kw vehicle chargers. ...
I am pretty sure that the DNO will not contract to supply 69 kVA. I am not quite sure how ADMD is applied to a single property, but I got 30 kVA.
More than one 22 kW charger seems silly. That's about 80 - 100 "mph" so unless somebody is spending several hours per day behind the wheel, that sort of power is just not needed. Even with a 100 mile round-trip commute (and no charging at work), each car would only be charging for an hour a day. One will do with perhaps a second 7 kW charger so two vehicles may be charged simultaneously.
I am sure that diversity will take care of things, but let's suppose that it doesn't. If the occupier is out for 8 hours per day and asleep for another 8, the only substantial use will be for 8 hours. Let's say that an average of 50 A per phase is consumed. That is 50 x 3 x 8 x 0.23 = 276 kWh per day. Let's assume a tariff of £0.15 per kWh. That comes to £41.40 per day or £15k per year!!!
