Utility Week

UTILITY WEEK | 14TH - 20TH SEPTEMBER 2018 | 29 Customers Wired for the future The way homes in the UK are wired restricts distributed generation to 4kW and EV charging to 7kW. It's time new homes went three-phase. Opinion Daniel Brown T he way we in the UK wire up our homes has not substantively changed in generations, and it is beginning to show. The practice of fitting a "single- phase" supply has its roots in the Victorian era when homes were largely fitted with connections that would support simple lighting systems. This system involved running "three phases and neutral" paper-insulated and lead-covered cables down a street. Each home in turn was connected with one of the three "phases and neutral". The most significant change to how this was done was in the 1930s when the voltage levels were more strictly regulated. This electrical system has kept the UK in good stead for generations. On it the average home has incorpo- rated a host of new applications and heat demands. So why change it if it isn't broken? To meet ambitious decarbonisation objectives, we at the Renewable Energy Association believe that how we think about homes has to change. The advancement of new power, storage, transport and heat technologies will drive the need for change, and looking forward we should be preparing for all new houses to be built with solar, energy storage, heat pumps and EV charging points included, potentially as part of the new-build package. Home technologies In fact, homes are already becoming more than passive takers of power – with around 800,000 domestic rooop solar installations across the country one of the first steps is progressing. By and large people appreciate self-generation, and for many this is the first step in adopting power storage and smart EV charging. Recent polling by Client Earth indicates exactly how popular these home technologies are: 62 per cent of the British public would like to fit solar on their rooop, 60 per cent would buy a home energy storage device, and nearly half would switch their car to electric. Between market demands and the policy drivers, to REA it is clear there is a role for more solar, more storage, more EV charg- ing and, as time goes on, more renew- able heat technologies such as heat pumps in the home. As a nation we should be prepar- ing ourselves for this shi. Distribu- tion network operators such as Western Power Distribution (WPD) are trialling the additional costs of wiring new homes in the UK with three-phase supplies. This involves running all three phases and neutral cable into each home. This is standard practice in many coun- tries on the continent and beyond. Discussions so far indicate that the cost of opting to install a three-phase over single-phase supply could fall and that one of the main costs is in installing a larger and slightly more expensive distribution board (DB). Discussions within the sector indicate that these DBs can be redesigned to be smaller, and with scale, become significantly cheaper. New standard The benefits of three-phase into the home would be to treble the allowable amount of distributed generation (solar and energy storage) that could be generated per home. Presently, there is a functional cap of 4kW for single-phase installations. It would also allow people to opt for a larger, hence faster, EV charging and would provide supply capacity in the future as people opt to install heat pumps. Three-phase house service connec- tions have also been identified as a means of reducing electricity losses on the low-voltage network, something now incorporated into WPD's long-term loss reduction strategy. Ultimately, such losses cost consumers. Managing this transition would require Ofgem and the networks to agree to uniformly introduce three- phase as a new standard. Currently, the networks are bound to provide "lowest cost solutions" to the con- sumer, regardless of whether it is preparing the home adequately for the demands of a changing technological future. We're not talking about throwing the existing book of wiring rules away – we can continue to wire homes in a similar manner but balance the load over the three-phase connections and then have the ability to supply the higher-demand units, such as the EV charger and heat pumps. We're also not saying that people can't install solar right now on a single-phase supply – the issue is that it is restricted to 4kW. Nor are we saying that a 7kW EV charger can't be connected – it can. The key point is that each home on a single-phase supply effectively caps one's ability to connect more than 4kW of distributed generation, and it also caps home EV recharge rate at to 7kW. By installing three-phase, both these figures rise to 12kW. The UK needs to see these technologies as part of a single, growing system and look ahead to future-proof the housing stock we're building today, thus reducing the long-term carbon emissions. Daniel Brown, policy manager, Renewable Energy Association

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