Homes should be fitted with three-phase electricity supply

The single “phase” electricity supply system, which has been the norm in UK homes since before the Second World War, should be scrapped for new homes, a report has urged.

The study, published by the Renewable Energy Association (REA), calls for all new dwellings to be fitted with a three-phase electricity supply to encourage the uptake of solar, heat pumps and electric vehicles.

The study, entitled “The feasibility, costs and benefits of three phase power supplies in new homes”, recommends that the government introduces a requirement that all new homes should have such connections.

Network operators currently run three “phases” within the mains cables, but generally only connect each house to one, says the report, which was supported by Western Power Distribution (WPD) , the distribution network operator for south-west England, South Wales, and the Midlands.

By contrast in other European countries, such as the Netherlands, all three phases connect to each house.

This allows loads from different appliances, such as washing machines and lights, to be split across the phases.

The existing system of single phase supply has worked while electricity demand has been relatively limited but will be overloaded by increased demand from electric vehicles (EVs), the report warns.

This pressure on connections will be exacerbated by the increased deployment of solar panels on homes and electrical heat pumps, it adds.

The installation of three-phase supplies would enable the total load of the house to be distributed over three phases, giving each individual home greater capacity.

This would allow consumers to charge their EVs more rapidly, enabling households to gear up for a future when electric cars have longer-range and higher capacity batteries.

However, according to the report, distribution network operators (DNOs) are compelled by regulations to install the lowest-cost solutions to the consumer, which acts as a brake on installing marginally higher cost three-phase connections.

Commenting on the launch of the paper, Mark Dale, innovation and low carbon engineer at WPD, said: “The distribution networks in the UK are in the middle of a major transition. Not only are we expecting the homes of the future to provide us with the energy to run as they do now, but we are also looking for them to fuel our cars and provide flexibility services to others.

“Traditionally DNO networks have been designed for distributing electricity from large remote generation sites to our homes. With the connection of more and more distributed generation on our networks we need to become more flexible in the way we design and operate our networks. The current policy of installing single-phase supplies in new homes has been the norm since before the Second World War and should be reviewed.

“Three phase connections will allow for more solar PV and battery storage, as well as for faster home EV charging. It will give customers and network operators the flexibility required to match demand and generation as efficiently as possible by utilising smart meter tariffs whilst, at the same time, reducing network losses.”

Dr Nina Skorupska, chief executive of the REA, said: “Additional costs to housebuilders are already low for a three-phase connection compared to a single-phase in new homes. If the government compelled the network operators to fit new homes in this way, the cost would fall even lower.”

WPD is currently conducting trials of three-phase connections in new homes, such as Parc Eirin Energy Positive Homes in Wales.

In its recently published Road to Zero strategy, the government committed to consulting on making the installation of charge points in new homes mandatory.