Electric vehicles and onsite power generation and storage will play an increasing role in the built environment. Neil Gerrard looks at the implications for building services installations.
Judging by recent government initiatives and technology advances, we are gearing up for a future where electric vehicles (EVs) rule the road while homes and businesses generate and store their own energy.
Transport minister Chris Grayling announced this July his intention that all new homes in England should have an EV chargepoint available, while battery storage technology – led by Tesla and its high-profile founder Elon Musk – is starting to emerge in both commercial and domestic applications.
But what is involved in installing these technologies and are construction companies ready to meet demand?
“There is already quite a high demand for electric vehicle chargepoints in new build,” says Kevin Knapp, managing director of Ecolution Group, which provides renewable energy services to the commercial and housing sectors.
“Local authorities are demanding they get put in, as are many housing associations. The noises are that it will actually be in the Building Regulations by next year.”
Leeds and Wakefield are areas where EV chargepoints are already part of standard planning conditions, which means David Faraday, technical director for Redrow Homes’ Yorkshire division, already has some experience in the field. On a purely technical level, installing them is fairly easy, he explains. “It is essentially a glorified outdoor socket. On a detached house it is relatively straightforward and as long as you know about them early on,” he says.
“EV cars go hand in hand with battery storage because they will basically level off the grid and you won’t have so much demand.”
Kevin Knapp, Ecolution
Complications can arise due to a lack of detailed guidance on what is a relatively new technology. Luke Osborne, the Electrical Contractors Association’s (ECA) energy and emerging technologies solutions adviser, says: “There has been some confusion over earthing requirements when it comes to EV over whether or not they should have a separate earthing spike put in.
“It seems a bit of a grey area up to now but the 18th Edition of the Wiring Regulations points out that it would be better to have a separate earthing spike for the EV and sometimes batteries.”
Infrastructure requirements can differ, says Steve Turner, director of communications at the Home Builders Federation (HBF): “Some local authorities have simply asked for an external 13A socket, while others have requested anything from a 5 to 7kVA outlet.”
Early agreement on the ducting and wiring required, as well as discussions with the Distribution Network Operator (DNO) on the infrastructure requirements and loadings are essential, he contends.
One question does remain – is the grid equipped to deal with the extra demand? Already there are an estimated 13,000 public EV charging points – five times more than in 2011. “The biggest challenge we face is that the grid can’t cope with too many EV charging points,” says Knapp.
He sees another technology – battery storage (see box) – as key to helping prevent this. “EV cars go hand in hand with battery storage because they will basically level off the grid and you won’t have so much demand,” he says.
Four companies in the UK are certified to install Tesla Powerpacks (Photon Energy)
Battery storage is still very much in its infancy, with relatively few examples of its application in UK buildings so far.
Photon Energy, which designs and supplies solar PV and battery storage systems and is one of only four UK companies certified to install Tesla Powerpacks, recently installed four energy storage units at Manchester Science Park alongside two EV chargepoints. The 2.2 tonne batteries were lifted onto a pre-constructed concrete plinth, using a flatbed lorry with a Hiab crane.
Photon Energy founder Jonathan Bates regards their installation as a simple process and little different to putting in a PV system or a generator.
“You basically need a suitable point of connection and the DNO considers a battery to be a generator so you need to make an application to the DNO to have permission to connect it [under Engineering Recommendation G59]. This is because it can push energy onto the grid as well as bringing additional energy to the site to charge it,” he explains.
Occasionally, installers may need to consider ER G100, which sets a limitation on electricity exported to the grid. As Osborne points out, smaller batteries for domestic use with an output of up to 3.68kW can be connected directly to the system if a G83 form has been filled out.
Knapp, whose firm has partnered with German manufacturer of smart energy storage units Hycube, sees battery storage as core to the functioning of a smart building. He views it as essential for the battery to be connected to the internet so it can talk to a building management system (BMS) or be controlled remotely.
At a commercial level, Ecolution offers containerised systems but can also provide systems that sit inside a building, housed in racks similar to those used for computer servers.
Rather than the technical challenges, he thinks cost is limiting adoption. It is the higher-end domestic projects, and commercial schemes where clients want to show their environmental credentials, where most battery storage can be found.
“The interest is beginning and it will move forward but there is a lot of educating to be done yet,” he concludes.
Installation of Tesla battery storage at Manchester Science Park (Photon Energy)
The case for battery storage
The Bloomberg New Energy Finance survey showed that lithium-ion battery packs were 24% cheaper in 2017 than they were a year before. Analysts expect them to fall further, from $209 (£160.70) per kilowatt-hour last year to $100 (£76.90) in 2025.
The reducing cost of lithium-ion batteries has opened up new possibilities for battery storage in homes and commercial buildings.
On a domestic level they can be used to store power from renewable sources such as rooftop solar power to be used when the sun isn’t shining, perhaps to charge up an EV overnight.
On a commercial scale, they have multiple uses including as a backup generator in the event of a power failure but also to insulate businesses against shifting commercial tariffs by providing power at peak times of the day.
They can be internet enabled to communicate with each other over multiple sites to smooth out power consumption, and also substantially reduce carbon footprint.
