Can the grid cope with electric vehicles?October 13, 2017
There’s been much talk in the media about whether the UK’s electricity grid can cope with increasing numbers of electric vehicles, and the different views primarily stem from whether this is looked at from a national or a local perspective; read on to discover the definitive answer to this question from both points of view.
The National Grid and a Distribution Network Operator (responsible for local electricity networks) both appeared on the same stage to answer this question at a seminar entitled ‘The Electric Vehicle Revolution: Managing Impacts on the Powergrid’ which preceded the Low Carbon Vehicle Partnership’s (LowCVP) Low Carbon Champions Awards dinner. The event coincidentally took place the day before the release of the government’s Clean Growth Strategy, which sets out a blueprint for Britain’s low carbon future, and includes a commitment to ‘develop one of the best electric vehicle charging networks in the world’.
Andy Eastlake, Managing Director of the LowCVP, chaired the seminar sessions, with Marcus Stewart from National Grid and Stewart Reid from Scottish and Southern Electricity Networks being the first two speakers, giving their views on the subject of ‘EVs and the grid’.
Firstly, in terms of the national picture, Marcus referred to National Grid’s recent Future Energy Scenarios (FES) report which provided four scenarios about differing levels of take-up of electric vehicles, and the resulting additional power generation required. This had been misinterpreted by some media, especially in the light of what Marcus described as “lots of excitement about EVs this year”, and he confirmed that the ‘two degrees’ scenario was felt to be the most realistic. This would need much less additional power generation than some of the other scenarios quoted in the media. Marcus made the point that this lower demand scenario was based on smart charging being adopted. Marcus also referred to other initiatives that would help, such as vehicle to grid (V2G), where an EV can provide a service to the network.
Marcus said that he expects EVs to develop rapidly; he is “positive about EVs but there is a lot of work to do”, and the UK “needs to get organised around this”. Our interpretation of what this means is that to achieve the lower demand scenarios for energy from electric vehicles, initiatives such as smart charging can’t be left to chance – someone needs to make them happen.
Stewart Reid from Scottish and Southern Electricity Networks (SSEN) agreed with a number of Marcus’s points, however the view about electric vehicles from a local network perspective is very different in many ways to that of National Grid.
SSEN manages local electricity networks – the low voltage (LV) network rather than the high voltage (HV) National Grid. One of Stewart’s key points was about the “law of large numbers”. If a number of people charge an EV at the same time, this will have little impact at a national level, because this extra demand will be lost within the millions of people using electricity from the National Grid throughout Britain.
However if ten people all plug in their EV at the same time on a local electricity network, which may only serve 50 properties in total, then the impact on this local network is much larger – especially when you consider that adding an EV on a network is equivalent to adding an extra house. So there is a mismatch between the national and the local situations. Although EV sales nationally are relatively low at the moment, it only needs clustering of a few EV owners in a local area to cause potential problems – and it is expected that such clustering is likely to happen. Stewart made the point that it takes just one overload for the lights to go out.
So in an ideal world, all local electricity networks would be upgraded to cope with the possibility of lots of electric vehicles. However that would result in huge cost and disruption. Stewart also raised the issue of who pays for reinforcement of local electricity networks. With a new housing development, the developer pays for the network (and developers generally want to pay the minimum cost, which results in minimum capacity). With existing housing, the cost of any upgrade work is ‘socialised’ – in other words, people who don’t own electric vehicles pay for upgrades for EVs.
The solution to avoiding unnecessary cost to protect against perhaps just one potential instance of excess demand per year is ‘demand side management’ – which could result, for example, in a signal being sent to a smart charger to defer charging for a short period of time to move it away from times of peak demand.
Stewart concluded by saying that we need to ensure that EV owners see that demand side management is a good thing and that they accept the principles. We need accessible open standards, and the industry needs to deliver the necessary data and control signals, communications infrastructure and the products and services needed. Perhaps most importantly, EV owners need trust in whoever is delivering all these services.
A panel session allowed further debate about EVs and the grid, specifically looking at ‘Managing EV uptake and grid capacity: The role of ‘smart charging’ and energy storage in facilitating mass adoption of EVs in the UK’. Panel members consisted of Dave Roberts from EA Technology, Peter Stephens from Nissan, and Mike Potter from DriveElectric.
Dave Roberts talked about the Electric Nation project, which is trialling smart charging with electric vehicle drivers. Recruitment for the project has been a huge success, with the target number of 700 participants now being in the pipeline five months ahead of schedule, and over 400 smart chargers have already been installed at people’s homes. However Dave’s main point was about how we take learning from trials and turn this into standards. To do this, the collaboration that has recently started between the automotive and energy industries needs to be accelerated. EA Technology and SSEN are currently working together with the automotive industry on the SmartEV project, which is looking at standards to ensure every single EV charger is capable of being communicated with in a consistent and coherent way.
Dave made the point that the pace of change of electric vehicles is growing, and this pace is outstripping the rate of change at which electricity networks can adapt.
Peter Stephens from Nissan agreed that smart charging will be needed, and explained that Nissan is involved with energy storage, solar and V2G systems, which will help us move from EVs being part of the problem to being a solution for the grid. However the key issue is how you get the business model to work.
Peter agreed with Dave Roberts about the automotive and energy industries needing to work together more closely, and he also included the area of digital in this collaborative approach.
Mike Potter from DriveElectric stressed the need to “think about things from an end user point of view”, and to make all the developments needed for EVs and the grid – such as the complex data behind V2G systems – simple for consumers.
The point was made that although many current EV batteries could have their charging paused overnight and still be fully charged the following morning, the next generation of EV batteries will need the entire overnight period if they need to be fully charged from empty from a domestic charge point (where a 7kW charger is the maximum that can be used on a single phase domestic supply).
Combined with EVs having larger batteries and therefore longer ranges, the audience was informed that the Benefit in Kind tax rate for EVs is due to drop back down to 2% in 2020. This could lead to a rapid take-up of electric vehicles, and result in many clusters of EVs with large batteries having a significant impact on local electricity networks as soon as 2-3 years from now. Therefore our conclusion is that action is needed now to deal with domestic EV charging issues and local network problems before they happen.
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