Electric Vehicles as “Energy Smart Appliances”

The British Standards Institution has just published a new “specification”, and unlike most BSI “standards” this one is free to download, as long as you don’t mind parting with an email address. As the download page puts it:

BSI is working with the UK Government to encourage the uptake of safe, secure and interoperable Energy Smart Appliances (ESAs). These are needed for the active management of demand on the electricity network, known as Demand Side Response (DSR). PAS 1878 is a critical component in this because it details the requirements and criteria necessary to make an energy smart appliance compatible with DSR activities.

At this point you may have a couple of question, such as “What on Earth is a PAS?”. The BSI have a ready answer for that question:

A PAS (Publicly Available Specification) is a fast-track standardization document – the result of an expert consulting service from BSI. It defines good practice for a product, service or process. It’s a powerful way to establish the integrity of an innovation or approach.

The next obvious question is “What has this got to do with electric vehicles and/or vehicle-to-grid technology?”. The answer to which is that a “smart” EV charging station is a special case of an interoperable Energy Smart Appliance. As the foreword to PAS 1878 states:

This PAS was sponsored by the Department for Business, Energy and Industrial Strategy (BEIS) and the Office for Zero Emission Vehicles (OZEV). Its development was facilitated by BSI Standards Limited and it was published under licence from The British Standards Institution. It [comes] into effect on 31 May 2021.

The introduction outlines the purpose of the new standard:

The purpose of this PAS is to enable standardized control, subject to an explicit consumer consent, of energy smart appliances (ESAs) on an electricity network in order to:

  • match the short-term availability of intermittent renewable energy generation sources such as wind and solar;
  • decrease the peak load on the electrical transmission and distribution networks to alleviate the need for network upgrades to handle new domestic appliance types, such as electric vehicle (EV) chargepoints and electric heating, ventilation and air conditioning (HVAC) systems;
  • allow control of electricity network characteristics such as line frequency, system inertia and network voltage, and help prevent network and generation outages; and
  • to allow the offset of short-term market imbalances by controlling flexible load on the network.

These aims are achieved by shifting (in time) and/or modulating (increasing or decreasing) the collective electricity consumption or production of domestic appliances, in line with consumer preferences and agreement, in response to signals from grid-side actors.

There is plenty more where that came from, but let’s skip a few paragraphs and then read:

It is also expected that other energy‑related services might be offered in addition to the minimum specification set out in this PAS and PAS 1879:2021, such as optimization of rooftop solar self ‑consumption with appliances or battery storage, that can provide additional benefits for consumers. The IEC 60364 series of standards provide guidance on the information exchange within prosuming electrical installations, e.g. IEC TS 60364-8-3:2020, Table 1.

PAS 1879 is a companion standard to PAS 1878, and is also available free of charge. According to the download page:

The PAS is intended for use by all actors operating within the domestic energy supply chain, including:

  • Transmission system operators (TSOs)
  • Distribution network/system operators (DNOs)
  • Electricity suppliers and aggregators

It might also be of interest to:

  • Manufacturers of ESAs and customer energy managers (CEMs)
  • Maintainers of ESAs
  • Manufacturers and maintainers of interfacing products
  • Software developers and other service providers

That is probably more than enough for you to consume in a single sitting, but to give you an additional flavour of what’s just around the corner at the “domestic” end of the UK smart grid, here is one of the numerous diagrams contained in PAS 1878:

Are there any questions?

19 thoughts on “Electric Vehicles as “Energy Smart Appliances”

  1. Hi Jim,

    I look at EV charging management. EVs alone overload the 230V networks, Heat Pumps are worse. The LV circuits are not built to deliver such power to houses (see my stuff at https://www.researchgate.net/profile/Steve-Broderick + references to reports going back to 2012; this issue is unresolved).

    Suppose a phase is about to overload – it will blow a substation fuse, sending many houses into darkness. This needs to be found in real-time.

    How is this detected? IS this detectable? How? I can’t see a mechanism for that; certainly there is no real-time data for load control for our very weak LV systems… what data there is gets scattered to 101 retail suppliers. Who take no action thus BANG! 🙁

    About 80% of our 450,000 km of LV networks are built for “lighting plus” (c. 1..2 kW) loads, not a 2050 load of 7kW EV + 9 kW Heat Pumps. Future 230V loads can exceed network limits by x5 to x10; there is no market or Smart solution here. We cannot deliver the energy @ 230V even at 100% throughput.

    PAS 1878 as a protocol offers no real-time data so cannot help. Expect changes / revisions at some point. And (according to ENA’s DS2030 report) a bill for c. £60 bn. MV/LV network rebuilds. Who pays that?

    If anyone knows the plan to fix this – please, what is it?

    • Hi Steve, Long time no see!

      As luck would have it I spoke to an electrician working just around the corner from the V2G UK offices a couple of days ago, and he assured me that he is still installing 60A breakers in new builds. Surely in this day and age new builds in the UK should all be 3 phase, as happens on the other side of North Sea?


      As I also asked in that article, in a not entirely unbiased question:

      “What about feeding power back into the grid when it needs more of it?”

      Or if full blown V2G is not yet feasible how about “local” distributed storage via V2H/V2B for that matter? Not so long ago National Grid’s Graeme Cooper stated that:

      There is definitely enough energy and the grid can cope easily.

      Was he forgetting about single phase LV feeders?

  2. When a NatGrid employee talks about “the grid” they are talking from their purview. They do not supply customers directly; that’s the DNOs job – and the DNO circuits across the EU are not built for this job.

    NatGrid supply power going to industry and commerce as well as homes; their systems are able to cope with the total load (which has been dropping over the last decades). Their networks are built to supply the peak they see. They cannot comment about local situations.

    DNO residential circuits are not part of NG’s role; they are built to supply a peak lasting a few hours – and are also often built at 0.8 capacity for this (systems will overheat, but then cool overnight). Built systems can be adrift by a factor from x5 to x10 i.e. 100 homes are cabled to supply 230V at a peak of (say) 150 kVA total, with a 120 kVA transformer fitted. NatGrid know nothing of this; it’s not their job.

    Also, actual 230V system builds vary from region to region and era of build.

    This has been long known and research + papers going back to 2008 mention this issue. Lots of research has been done. Outcome: Can’t fix it; rebuild necessary.

    There are about 330,000 UK transformers, c. 1 million feeders amounting to c. 450,000 km of buried cabling here. Of these, from 10-20% may be OK – but to assess this, and which and where and when… is a difficult, laborious job.

    • Thanks Steve,

      There are a number of threads to try and untangle here!

      1) There is a sense in which DNO residential circuits are now part of NG’s role, since they have recently undertaken to acquire Western Power Distribution:


      Why do you suppose they did that?

      2) When I mentioned “the other side of North Sea” above I was thinking specifically of The Netherlands. There are assorted V2G pilot projects going on over there, and since we’re members of the Open Charge Alliance I have visited the country many times. According to the UK Renewable Energy Association, introducing their 2018 “New homes shouldn’t be held back by pre-WWII electrical standards” report:

      The current model in the UK is for housebuilders and network operators to run three ‘phases,’ within the mains cables, down a street but to only connect each house to one of the phases. In other countries, such as the Netherlands and others on the continent, all three phases connect to each house allowing loads from different appliances, such as washing machines and lights, to be split across the phases. Regulations governing the activities of DNOs currently compel them to install lowest-cost solutions to the consumer. This constrains them from installing marginally higher cost three-phase connections which would better prepare homes for clean energy deployment.

      3) I started writing firmware for 11 kV fault data acquisition equipment back in the late 1990’s, so I am well aware that there is a “long known problem”!

      Our “long suggested solution” is displayed in the artist’s impression in the banner image at the top of the V2G web site.

      For the reasons you’ve described centralised electricity generation isn’t going to cut the 21st Century mustard without massive investment in cables and ancillary equipment. But how about distributed generation and storage coupled with a (very!) “smart grid”?

  3. Beware of “Smart Smoke” aka snake oil. No single or grouped smart approach can help, because all they do is optimise throughput to the sustained peak of the equipment, as set by physics. But the gap between peak ability and needed is too big to span.

    My work with DSR and V2G showed that a local optimising controller (and co-operative EVs) could limit loads to 2 kW per house average; however that number is above the capability of many residential networks.

    Top-drop DSR from retailers / aggregators can provoke early 230V system failures 🙁 but, home heating by Heat Pumps is “game over”. Suddenly 10-12 kW per home on top of EV load is being pulled; only the few networks built for this (10-20%) are able to deliver.

    Of course, this is political as:
    a) £ as much as another HS2; the £60 bn. estimate is old
    b) digging up most non-motorway roads in the UK.

    People will winge severely with either situation: Can’t charge my car because charging is banned in my street; can’t drive on these roads dug up for the last 5 years and still not finished.

    Note the politicos have been advised re this since 2012, but… it does not effect this parliament.

    • As per the artist’s impression above did your work also incorporate distributed electricity generation and “static” as well as “mobile” energy storage?

      “Energy” including heat as well as electricity.

      • Hi Jim,
        My focus was on EVs using V2G, local controllers and PV. Heat Pumps did come in. It was clear traditionally built systems could not support EVs, let alone anything else – and the failure is by a great gap, not a few %.

        Let’s outline the Winter situation. All numbers are rough approximations.

        Demand in 2050 per day, per house: c. 10 kW x 10 hours + 18 kWh = 118 kWh (HP heating + one small EV)

        Traditional LV circut can supply per house in a day: 1.5 kW x 24 = 36 kWh.

        That is, there is a shortage of 82 kWh per house per day. This is an energy shortage, which Smart cannot help with – already the system is assumed to be running flat out at 100% built capacity. It can do no more. In 2050, around 15 million homes will be in this situation. We need find about 1.2 TWh per day.

        Note that using storage is potentially a bad idea – losses of c. 20% are normal (some tech is worse). If storage at 80% efficiency was available, we would now have to generate 1.5 TWh per day to make up for the losses.

        What alternative energy source is there that can meet this gap? I do not know of a local one. Ouch. However we do have centralised generation…

        These sort of numbers are why NatGrid has focussed on the generation side and their cables, although NG do have the bad habit of talking about their system as “the grid”. Well, NG own about 2% of the total UK grid, which (from the inside of NG) seems an awful lot.

        • Hi Steve,

          Would you care to play “What if?” with me?

          “It was clear traditionally built systems could not support EVs, let alone anything else – and the failure is by a great gap”.

          Where did your figure of 18 kWh come from? The worst case obviously needs to be catered for as well, but the average UK commute at ~4 miles per kWh works out to < < 18?

          What if in 2050 lots of people no longer commute to “the office”, and if and when they do they use “autonomous” (mass?) transport?

          “What alternative energy source is there that can meet this gap? I do not know of a local one.”

          Here in North Cornwall many local farmers own wind turbines. Some of them even own entire wind “farms”:

          What if a massive R&D investment over the next 30 years resulted in the development of a wide range of “civilian” small modular nuclear reactors? Here’s a 70 MW module recently installed in the Russian Arctic, which also generates heat:

          What if in the middle of a windless winter you could drive a future incarnation of Lisa the LEAF to a nearby “filling station” located close to National Grid ETO’s 132 kV grid, top up her 60 kWh battery pack and then return to your “home office” and use that stored energy to keep the lights on for a few days?

          Please bear in mind as we play this game that IEC TC 69 JWG 11 is valiantly trying to finalise the draft international standard catchily entitled IEC 63110 part 1. “A protocol for the management of electric vehicles charging and discharging infrastructures – Basic definitions, use cases and architectures”.

    • @Steve Broderick
      I don’t disagree that there will be lots of LV reinforcement required, but you figure for heat pumps is wildly inaccurate.

      It’s expected that an average UK home will need a 6-8kW thermal output heat pump. The electrical input will peak at around 4kW for an 8kW heat pump, but there will still be a small amount of diversity and they needn’t run at the same time as EV charging, given average EV use is about 1hr of 7kW recharge per day.

      • Hi Rachel,

        It’s nice to see you here in my humble abode.

        If you’ve seen my recent activity on LinkedIn you may well suspect that I’m in “startup” mode at present. Accurately!

        Sorry for the delay in approving your pertinent comment.

        I don’t know if Steve is watching this by now ancient conversation. If he doesn’t show up I’ll try gee him up when (if?!) I have a spare 5 minutes.


      • Hi Rachel, Jim…

        🙂 cold snaps can last a week – so we can’t use averages. Cold snaps hit whole regions, which is a problem. COP for the HP falls off of a cliff; some systems dip below 1 (heat-exchanger defrost, flow-boiler in use as HP contributing nothing) – yes, exceptional but can you say where and when this will/will not happen? A COP of 2 perhaps is more representative… but that’s a guess; the data is still coming in for retrofitted estates of houses.

        Plus EV charging is nowadays concentrated overnight, often into a 6 hour or so window. Q: will people plug-in every night, or leave it a few days as they have plenty of power?

        Might be a good idea to do a study here into “UK as is now”. My work was mostly set in 2017 looking out to 2050, but “reasonable assumptions” have since changed.

        All good fun!

  4. Some input regarding “consumer protection” in a future UK smart energy market from Octopus Energy CEO Greg Jackson on Twitter:

  5. Let’s see if WP censors this comment.

    The fact that past assessment’s have been siloed (as low-level analysis very difficult) is starting to percolate through. See: https://www.current-news.co.uk/blogs/national-flexibility-vs-local-the-benefits-of-moving-away-from-a-siloed-approach which notes a £55 bn. issue. Such low-level approaches give results invisible at top level, essentially as local peaks (and problems!) are averaged away at NatGrid level.

    [Requested correction applied – Mod]

    • Good morning Steve,

      Sorry for the technical SNAFU, which is hopefully now fixed?

      Assuming for the moment that there is a £100 billion “issue” here in the UK, how should that money be spent? On traditional “reinforcement” or on a shiny new “distributed smart grid” or on a potential “third way”?

      To be continued!

      • 1. first gather some sticks (traditional start to recipes).

        The point here is not how to spend the ££, trick #1 is to get some. Who will pay? There is no profit for spending this money:

        a) the traders / markets want to keep any ££ profit, not fund the infrastructure
        b) suppose company XYZ spends this ££. How do they get it back? Ofgem prohibits price rises (DNOs make c. £87 per customer pa, with c. 4% profit)
        c) what sort of price rise are we looking at? Suppose over 20 years £100 bn. spent. Let’s say the interest rate is 5% on the capital, and to simplify matters say that amount comes to: 10 yrs x 0.05 x £100 bn. = £50 bn. Plus the capital, £150 bn. over 20 years so that’s (for 20 million homes) £375 per customter pa. Today, no… too political alas. Plots a lot of roadworks.

        The UK has c. 330,000 LV substations and c. 1 million feeders with about 450,000 km of buried cables. Sustained demand per home is c. 7-9 kW which the network must deliver (I can hear the provisos re distributed gen – how much is that going to cost per house?); but only c. 10-15% of the UK LV network is able to deliver this i.e. c. 80% need replacement (and likely many MV systems too). A traditional build has 1..2.4 kW ono built systems, often with under-rated assets to boot (as peaks are short timewise).

        Given Smart anything cannot magnify sustained power delivery from 1 kW to 9 kW (an energy analysis easy shows this) then the network reinforcements are obligatory. Smart can manage peaks, but as the peak is reduced so the load spreads timewise.

        However there are 2 forms of Smart, as pointed out by Prof. Strbac. Network optimising and peak (market) optimising. These have different objectives – the first does not make ££ but limit local costs, the second one can make money at a national level. Which we hear about, yet the first form is often forgotten. These methods are “enemies” in that meeting one frustrates the other. Yet, the first form is seriously considered as it defers £bn’s spend for c. a decade+. Expect this to happen.

        Next up – V2G. Local Smart in the first form (network costs reduction) can mimic V2G by finessed local control. Also, local V2G export is often “wasted” in that V2G exports lift local headroom – and gets consumed (assuming a shortage of power – which is why V2G is called for). The V2G power does not escape the local situation… so is not seen at national level. Ie is ineffective. Oops.

        The whole set of circumstances behind this have had years of study, by several teams as well as me.

        Another way to look at this is to assume each home is isolated then try to get power to it. Gets expensive fast.

        Ultimately this is a national level problem; in discussion of these issues (c. 2011) the consensus was: The power Co’s do not have the ££, thus they must be nationalised (in some form) and the Government pay. Presently; it is hard work just getting people to realise there are major problems. Suspect this is because commercial organisations chase / fetish over profit, and run away from costs. So it is not discussed – the elephant in the room.

        • Hi Steve,

          Undoubtedly this is a national level problem but sticking with the South West region for the moment, Western Power Distribution is our local DNO/DSO and is currently being acquired by National Grid. In the foreword to WPD’s most recent “Distribution Future Energy Scenarios: Regional Review” Ben Godfrey suggests that:

          The DFES projections are used to assess the distribution network and identify areas of strategic network investment, which can be delivered through conventional reinforcement or a range of smart and flexible solutions. By performing this study, WPD is able to demonstrate that we will be able to continue to meet the needs of our customers as we transition to a low carbon future.

          In our parallel conversation over on LinkedIn Ben also seems to be suggesting a “third way” forward:

          No doubt that the LV networks will need reinforcing, but the big questions are what, where and when. We’ve removed tapered from our designs and consolidated our conductor sizes, so everything we replace going forward will be fit for 2050. Intervention (if any) needs to be timed just ahead of need to minimise bill impact and this is where flexibility will help.

          We’re already seeing impacts of energy efficiency in the home, and incentivised time of use for EVs. Add in some demand side response actively coordinated by the networks and this will be an important leading indicator/mitigation tool ahead of any potential reinforcement.

          Flexibility can also help us respond quickly to unforseen increases, but for it to be useful, it needs to be ubiquitous.

          Somebody has got to pay for it all of course, but if that problem can be solved do you still have strong reservations? It certainly sounds like it!

          Hi Ben, these will help in the short term but fail in the long.

          There is no Smart solution, individually or in combination, which fix LV systems built for gas-heated homes.

  6. Earlier today Regen released a report that speaks to these issues. Here’s a (very!) brief extract:

    Electrification: The local grid challenge

    The electricity network is critical to decarbonising our homes.

    Domestic heat pumps, electric vehicle chargers and rooftop solar panels all have one thing in common – they need a connection to the grid.

    There has been extensive focus by policymakers on upgrading the transmission network.

    This paper looks at what it will take to ensure the distribution network is ready for net zero. In particular, the paper focuses on the ‘local’ high-voltage and low-voltage networks…

    UK government
    The government should make upgrading the local grid in time
    for net zero one of the UK’s critical infrastructure programmes
    of the next 25 years to 2050.

    Ofgem should reform the price control process to require
    DNOs to plan and deliver a long-term programme of
    investment that will ensure the distribution network is ready
    for demand forecasts set in the upcoming Regional Energy
    Strategic Plans.

    UK government and Ofgem
    The government and Ofgem should ensure local and national
    arrangements for flexibility are coordinated to optimise the
    system as a whole.

    Distribution Network Operators should:
    • Use the mechanisms in their budgets for 2023-2028 to
    scale up local network upgrades.
    • Produce and publish data on capacity and constraints on
    their secondary networks as a key priority.
    • Accelerate development and rollout of local flexibility
    • Ensure local network planning is prepared for a reduction
    in diversity of demand due to stronger wholesale pricing
    signals and electrification of heat.
    • Deliver a streamlined, digitalised connections process.

  7. In other recent news the National Infrastructure Commission reported in February that:

    The government has asked the National Infrastructure Commission to provide recommendations on the policy decisions required to make the electricity distribution network in Great Britain fit for net zero.

    Our approach will be informed by the terms of reference for the electricity distribution network study.

    The lower voltage distribution network connects the high voltage electricity transmission network to homes and businesses. Smaller sources of generation and flexibility, such as solar and batteries, also connect to the distribution network. The owners of each part of the distribution network are regulated by Ofgem, which sets the outcomes that must be delivered and the revenues that may be collected.

    As the economy decarbonises over the next decade and beyond, electricity demand is expected to materially increase. This increase in demand will mean electricity networks at both transmission and distribution level will need to carry more energy. The availability of capacity on the network, in terms of the volume of electricity it can carry, will be important to maintaining service levels and ensure the system is resilient. Without available capacity new sources of supply or demand will not be able to connect. This could constrain the speed of decarbonisation if, for example, consumers cannot connect electric heating appliances or electric vehicles charge points, or industry cannot secure the level of connection it needs.

    Investment to increase capacity is likely to be needed, but the amount could be reduced through further application of non-network solutions, such as the use of local flexibility markets, enhanced use of demand side response and improved use of data and digitalisation…

    The Commission will provide final recommendations to government within the next 12 months. The government has an obligation to respond to the recommendations made.

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