UK Power Networks and Northern Powergrid on the need to define what smart charging actually means, greater low voltage network visibility and how businesses and local authorities can ensure a smoother EV charging infrastructure rollout.
UK Power Networks has one key message for organisations planning electric vehicle (EV) charging infrastructure rollouts, says Adriana Laguna, senior innovation strategy manager at the distribution network operator.
“Talk to us. Consider your long term needs, then we can work together towards the best long term solution.”
As EV chargers increasingly connect to the low voltage network, lack of visibility is a key challenge for DNOs.
“We traditionally have not monitored secondary substations – and that is a shift the industry is going through. What was a top down network is changing, all the action is taking pace on the LV network,” says Laguna. “And we need visibility both ways, so understanding where EVs are connecting is a good start; the better data we have today, the better we can plan.”
How smart is smart?
Deploying a smart approach to charging is necessary in areas that are likely to become constrained. “That can be anything from a simple timed connected to active network management,” says Laguna.
But one of the challenges facing industry is defining ‘smart’. “What does smart charging mean, what does it require from an IT architecture perspective and how do you make it standardised,” Laguna explains.
“We [the DNOs] all agree that smart charging should happen, so how do we as networks enable anyone that wants to do smart charging to do so and what do we need to have in place?”
UKPN’s Smart Car innovation trial examined different smart charging models, from DNO controlled to free market approaches.
“The conclusion was the market-approach was generally favoured by customers,” says Laguna. “So the next phase at the project aims to test what a market signal looks like, working with suppliers, operators and owners to see how efficient that is.”
For business deploying EVs, particularly those with larger fleets, a smart approach is necessary to mitigate cost. Laguna cites UPS as an exemplary case study.
“UPS is embracing change. They approached us, we worked with them to define their minimum power requirement and how to optimise behind the meter, how to maximise the connection [capacity] that they have on site.”
The benefit goes both ways, says Laguna. “Partnering on that project and taking a different approach to connections has been very eye opening.”
Meanwhile, deploying storage and active network management at the UPS site shows what is possible.
“These are the kind of solutions customers definitely need to look at to optimise their connection,” says Laguna. “Storage is a fantastic example of technology evolving to get the most out of the network – and to put back in. Again, there is a lot of education required, and that is where we can definitely help.”
Smarter thinking required
Iain Miller, head of innovation at Northern Powergrid, agrees on the need to define smart charging.
“Getting government policy right, that in itself is a smart option,” he suggests.
Miller says intelligence is also required around price signals for smart charging, given the changing generation mix.
While there is a view that charging might best occur overnight when demand is lower from businesses and households, there is also less generation output overnight. “So it makes sense to charge vehicles during the day as well,” he says.
Should solar generation continue to grow, charging during the day might become more attractive in future, says Miller. But if EV owners react en masse, it could create challenges for DNOs, whose networks are built around a diversified maximum demand.
“If a signal comes through that says, ‘it’s sunny, power’s cheap, start charging’ and everyone reacts, that would be more than the system is designed for and may cause significant issues,” says Miller.
“Equally, we should not be telling people they cannot do that when wind and solar are available.”
He says one solution is to consider where solar is located in the first place. From a domestic perspective, using rooftop solar is ideal, he says, because it then never needs to be exported onto the network.
Bundling EVs, solar and storage would enable a “useful, joined up” approach, from that perspective, says Miller. It would also help enable new network models.
“We like the idea of fractal balancing or nested microgrids, essentially the same thing,” says Miller. That is, balance the house and transfer as little through the meter as possible, then incentivise balancing of the local distribution substation, to minimise usage of the high voltage system, which in turn is balanced to minimise use of the extra high voltage network.
Theoretically, that approach could lead to “a point where you almost never call on National Grid, which total changes the way the energy system runs”, focusing on the user upwards rather than top down, says Miller.
However, Miller also sees merit in laying fatter LV cables, given it adds little cost if networks are digging up the road anyway.
Meanwhile, he says it is incumbent to direct local authorities, communities and business to the best places to install charging points.
Northern Powergrid will launch a mapping tool later this year that allows developers to input what they wish to install, and the system will show “feeder segment by feeder segment” where they can install, with or without reinforcement. Miller says in some case that can differ from one side of the road to another.
It will also give a budget quote in real time – or minutes at least – depending on location.
“That should make life easier,” suggests Miller.
This article was published in The Energyst’s 2019 EV Report.
The report includes a survey of more than 100 businesses and details their EV and charging plans as well as attitudes to smart charging and vehicle-to-grid services.
It also contains interviews with other businesses switching fleets to EVs, charging point companies, distribution network operators, consultants, carmakers, technology firms and energy suppliers.
Download the report, free of charge, here.