Network innovation: revealing the path to smart grids

Distribution Network Operators (DNOs) know networks will have to cope with electric vehicles, distributed generation and demand side response in the future. But the extent to which these technologies will benefit DNOs is only just becoming clear thanks to the Low Carbon Networks Fund. Lucinda Dann investigates.

Ground breaking trials by two of the projects have revealed DNOs can expect to make multimillion pound savings by adopting these technologies, with the benefits to the country as a whole running into billions. The projects’ findings will provide the route map for all DNOs as they navigate technology adoption over the coming decades as cost-effectively as possible.

The LCNF has supported 23 projects over five years, and while projects have vast costs attached, £28.3 million for UK Power Network’s (UKPN) Low Carbon London and £28.6 million for Northern Powergrid’s (NPG) Customer-Led Network Revolution, the projects had to provide significant benefits, not just for the network company undertaking the specific project, but the whole system.

NPG says its project has opened the door to up to £26 billion worth of net benefits to Great Britain by 2050. There will also be “larger cost savings” of around £400 million after 2023 for its customers. UKPN say its project has allowed them to save £43 million in network investment over the next eight years.

The projects have been described by Ofgem as two of the “most ambitious” undertaken into smart grids to date. Both have measured a range of disruptive technologies including the flexibility of consumers for both demand side response and electric vehicle charging, and the impact of technology on connecting distributed generation, critical information to enable the move to smarter grids.

Ofgem senior partner for distribution Maxine Frerk said: “Energy networks are facing significant challenges in moving to a low carbon future and ensuring costs are kept low for consumers. Ofgem’s LCNF has helped network companies respond to these challenges.”

UKPN’s head of future networks Martin Wilcox said: “Low Carbon London provides key information to urban DNOs to enable the uptake of home and workplace EV charging, supports the increase in combined heat and power plants in urban areas, and facilitate home electric heating and micro-generation uptake.”

The Customer-Led Network Revolution has raised some concerns. Northern Powergrid has warned that distribution tariffs and technology trialled in the project will only become cost effective if they also deliver benefits to suppliers. It says its learning must be shared so industry and policy makers can work together to design tariffs that incentivise desired peak load shift.

Frerk said: “We now expect companies to learn from the experience provided by the projects under the scheme, share it across the industry and embed innovation learning into their culture and practises.”

UKPN’s Low Carbon London

Project cost: £28.3 million

Headline benefits: Delay to £43 million of investment in assets

Electric Vehicles

Problem: High EV uptake could result in peaks of simultaneous charging, potentially overloading the system.

72 domestic, 54 fleet and 1,408 public charging points were studied to provide information on how much networks must be strengthened to cope with extra electricity consumption from EVs.

Findings: As the number of EVs increases total average peak demand from EV charging decreases. When above 50 EV users are connected DNOs only need to accommodate 20 per cent of the maximum total demand.

70 per cent of the EV users modified their charging behaviours when incentivised to do so.

DSR

Problem: Calculating the level of network reinforcement that could be cancelled out by reducing demand at peak times.

Findings: 37 participants including hotels, major shops and visitor attractions took part in the trials, voluntarily reducing their electricity consumption sufficiently to serve 18,000 homes at peak time.  

UKPN will use DSR to manage particular sites which are occasionally close to their capacity limits, but where upgrading the network would provide more capacity than needed.

Distributed Energy

Problem: Networks were designed to expect generating plant to be a long way away, but targets are set for 25 per cent of energy in London to come from decentralised sources by 2025.

Findings: By integrating monitoring data from both CHP and Potovoltaic sites with other generation data greater visibility was achieved of whether decentralised plants are operating or down for maintenance.

In the London network, 70 out of 114 primary substations could benefit from using active network management to recognise the current configuration of the network, allowing up to a third more distributed energy plants to export power to urban networks.

Northern Powergrid’s Customer-Led Network Revolution

Project cost: £28.6 million

Headline benefits: Larger cost savings of around £400 million beyond 2023 for Northern Powergrid’s customers. Net benefits to Great Britain of between £5 and £26 billion in the period 2020 to 2050.

Time of use trials for domestic customers

Problem: Time of use tariffs will follow smart metering, but the level of flexibility by consumers and effectiveness of incentives to shift demand are little understood.

Findings: The tariffs are popular and easily understood by domestic customers with demand being reduced by 10 per cent between the 4-8pm evening peak as compared to a regular tariff.

The majority of customers are inherently flexible, exceeding expectations, with laundry and dishwashing the most moveable activities. Smart washing machines was found to have limited benefits. Heat pumps successfully reduced peak load by 2.5kW but significant barriers around retrofitting were identified.

Domestic customers were also found to contribute less to system peak demand than expected. Northern Powergrid has recommended a 42 per cent reduction to 0.9kW per customer.

Electric Vehicles

Findings: EV uptake on the network will first be felt in rural locations. For offpeak charging to become commonplace EV users must feel confident in automated overnight charging systems.

Northern Powergrid recommends an uplift of only 1kW per customer with EVs and heat pumps.

DSR SME

Findings: SMEs showed significant reluctance to flex their usage. SMEs should also be classified by energy use to acknowledge the wide diversification. New, potentially bespoke tariffs will need to be designed for this consumer group.

DSR I and C

16 I and C customers provided a total 17MW DSR 80 per cent of the time. Northern Powergrid will use DSR between 2015-23 to manage fault conditions and security of supply at substations that will be occasionally overloaded. DSR could provide 10 per cent of additional headroom.