Bidirectional Electric Vehicle charging - could this be a game changer to support widespread EV adoption whilst strengthening the grid?

There is an increasingly urgent debate on how to accelerate electric vehicle (EV) adoption to reduce CO2 emissions from fossil-fuelled vehicles.

For instance, in the UK, the government is pushing for the transition to zero-emission vehicles, aiming to phase out petrol and diesel cars by 2030 (
https://www.gov.uk/government/news/industry-encouraged-to-shape-uk-transition-to-zero-emission-vehicles#:~:text=The%202030%20phase%20out%20date%20was%20broadly%20supported%20by%20industry,to%20electric%20cars%20by%202030).

One commonly cited challenge is the concern that “the grid can’t handle the power demand of widespread EV deployment.”

But what if each new EV could be an asset to the grid rather than a burden?

In my view, bidirectional charging could be a game-changer, creating a "positive tipping point" for both EV adoption and grid stability. How Could This Work?

Grid Perspective:
Every EV plugged into the grid could provide valuable energy storage. Excess renewable energy (from solar or wind) could be stored in EV batteries during periods of low demand and released back into the grid during peak times, reducing reliance on fossil fuels.

Moreover, if EVs are charged at home or near points of demand, they could provide localized storage, decreasing the need for long-distance transmission and reducing grid losses. 

The Role of AI:
Real-time spot tariffs could be broadcast to smart chargers, allowing them to respond to the grid’s need for additional power. AI algorithms could also predict weather patterns, helping to plan charging schedules based on upcoming energy production from renewables.

Charger-Owner Perspective:
Charger-owners can buy energy at a low spot rate and potentially be paid to take on energy during periods of excess supply. They could then sell energy back to the grid at a higher spot rate during periods of peak demand. If the owner also has solar or wind energy production, the incremental cost of this energy could be close to zero.

Driver Perspective:
The only inconvenience for the driver would be the need to plug in the vehicle. This could happen when they arrive at work or home, and app-based guidance could optimize charging times based on driver preferences.

Vehicle Perspective:
While each EV has embodied carbon from battery production, using the battery for grid storage could maximize the benefits of this "carbon investment." It’s a way of leveraging the vehicle’s potential beyond just emission-free driving.

Material / resource demand Perspective:
By using EV batteries for grid storage, the need for home batteries might be reduced, avoiding the demand for additional storage capacity and the associated environmental impact from mining operations.

Climate Mitigation Perspective:
To mitigate climate change, reducing CO2 emissions is essential. Bidirectional EV charging could create a positive feedback loop, decreasing emissions from both vehicles and the grid. The potential for fewer home batteries would also reduce embodied carbon associated with their production.

Climate Adaptation Perspective:
Severe weather events, intensified by climate change, could disrupt the grid. In such cases, EVs could provide backup power. With advance warning of extreme weather, drivers could ensure their batteries are fully charged. Since EV batteries typically have much higher capacity than home batteries, they could offer autonomy for multiple days in the event of grid failure.

Work and Home Considerations:
The interaction between work and home charging (and the potential for energy consumption at both locations) could introduce complexities, especially around remuneration and tax regimes. This could be addressed by borrowing the "Virtual Private Network" (VPN) concept from telecommunications, ensuring energy billing aligns with both remuneration and tax considerations.

Conclusion:
Many IET members are likely to be involved in this debate, so I would appreciate hearing your thoughts, as well as any corrections or guidance on my use of terminology.
(I am not a professional in this domain but am deeply interested from both a climate crisis perspective and as an enthusiastic EV and "active house" owner.)

Parents
  • I have seen discussions in the past looking at problems of locally overloading part of the distribution network. The load on a cable is usually monitored and controlled at the traditional source point, 800A fuses in the substation for example. A significant V2G source on that cable segment could allow an overload. A depot for EVs could be capable of sourcing a couple of hundred amps.

    The principle you are suggesting, using V2G in a local part of the network to reduce the need for expansion of the wider grid seems to increase that chance of this without significant local monitoring.

  • Can you show me some numbers from a non biased source supporting the costs in this statement?

    Hi Roger - I think this MIT article provides a fairly balanced view, which also emphasises the need / cost of storage to support wind & solar.

    That's the reason why I think V2G could be a significant technology, as the storage being deployed in EVs could become part of the solution. 
    The MIT article also mentions that the cost of fossil fuelled solutions don’t count the cost of the environmental damage caused by the fossil fuels.

    The article also mentions: "when most Americans have a big battery in their cars or a backup battery in their homes, that storage capacity could help balance the grid as a whole."

    I understand why nuclear is gaining interest - but my personal view is that planning / implementation timelines will need to be accelerated to make a meaningful contribution towards meeting Paris Agreement goals; maybe modular nuclear can help here?
    I summarised some thoughts on Nuclear vs Wind a while ago in this post

  • Couple of other issues.

    Most people can't afford any of the new tech.

    EV sales are plummeting, cost of living is exploding, CO2 levels are rising, fossil fuel use is expanding. Do you really think plugging a car into the grid is going to save the planet.

    Not that it needs saving.

    Nature always wins and hopefully common sense.

    I wouldn't take an MIT article as factual. 

  • In the uk we have the highest cost energy in the world due to the net zero transition to renewable. This will only increase as turbines and panels increase.. 

    Bare in mind that we need to spend trillions of pounds on infrastructure to accommodate the grid expansion. 

    The countries economy is a complete mess so where's all the cash coming from?

    Hi Jon

    if cost is your main concern, please don't ignore the cost of the effects of climate change - particularly significant for the UK.

    I agree the proportion of EVs in the UK is currently low (and probably only a small proportion of these are V2G capable). 
    This is the reason for my original post - to increase the future proportion of EVs that are V2G enabled, so that EV's can help reduce the future cost of the grid infrastructure by providing storage distributed throughout the network. 

    Stuart

  • Your barking up the wrong tree with Climate Alarmism.

    I've read enough science facts to educate myself off the nipple of doom.

    You should try it it's quite enlightening 

  • Another point is that the CO 2 footprint of an EV is massive. Maybe 50K miles before it goes positive.

    Plus the CO2 footprints claimed  never includes the upstream costs like transportation, manufacturing with Chinese coal fired power stations and mining of minerals by Conganese children and pregnant women. 

    Built by slaves, maybe a 20% CO2 saving over 100K miles. Might need a new battery after 10 years, worthless second hand value. Why on earth would I want to own an EV. Definitely not to prop up a failing energy system.

  • Anything that say 'could' rings my BS bell.

    And this from your link says all I need to know!

  • There is a slight risk that V2G could be used as an excuse not to invest in updating the grid 'properly', in terms of replacement transformers, thicker cables and so on. We have about a century of grid design experience design around centralized generation, and voltage drops that slope downwards towards the load, we have a similar length of time that has led to reliable design rules, like 1.5 -2 kW per house when sizing substations, and an arteries and branches approach to cables that means that the street main has an apparently oversized cross-section, when looking at those average loads, so that any one house can draw 100A for as long as it needs to. But no more than perhaps half a dozen houses in the street can do that at once, or the substation fuses pop ! And historically that never happens, and the design rules work OK,

    A transition to electric heat pumps for heating and electric cars that need charging, at least if you expect cars to be charged at home, and not at dedicated charging hubs with their own substations, renders all those DNO design rules and assumptions obsolete, and replaces it with 'here be dragons'.

    The ability to borrow a few tens of amps from the neighbour and save roasting the substation may initially look attractive, and allows some demand leveling, but then so does the far simpler measure of staggering the charging times that share a phase on a substation. At the moment, conventional  EVs are still a fairly niche thing - there are none in my street  for example but there are a few in total on the whole housing estate, so maybe less than ten per substation at the moment.

    Equally I don't live in a street of detached houses where folk buy cars new from a main dealer - those that do will have a different perspective on 'normal' ;-)

    I see that there is a lot of network reinforcement to be done before say every third house that currently has a car, can have an EV - V2G may be a way to shirk that.

    Mike

  • https://youtu.be/K8Nz-4eEBTw

    Mark P Mills gave this speech on the Economics and Future of Electric Vehicles on November 12.

    Well.worth an hour of anyone's time to listen to him.

  • Hi Mike - some good thoughts.

    I understand your view about V2G leading to risk of non investment in network upgrade.

    I also like your thought about staggering charging - "smart" chargers could manage this recognising the capacity in the local network versus demand. People could be rewarded (with low cost) for scheduling their charging in advance (hence easing the management of the demand on the network). 

    I'm thinking V2G may be a way of extending the lifetime of existing infrastructure such that the future investment could be optimised (e.g. prioritised based on the weakest points in the network.)

    As solar and wind will play an increasing role in the future, and these are more distributed in nature than the centralised power station concept, I suggest that new investment would be optimised by recognising this de-centralisation rather then re-creating the centralised architecture of the past?

    Stuart

  • I'm thinking V2G may be a way of extending the lifetime of existing infrastructure such that the future investment could be optimised (e.g. prioritised based on the weakest points in the network.)

    quite, but if we only do that at the pace of the current system has developed, then it will take 70-120 years to complete, by which time the goalposts will have moved again.

    Generally the  UK system either dates from when the house was built if post war, or from whenever the pre-war supply (if any) became inadequate for increasing load.

    By way of anecdotal support for my 70-120 year figure.

    I'm not sure how old the transformer that feeds your house is for example. but the one that feeds mine was installed at some point in 1969, and there is an adjacent unused pad for another to take extra load that has never materialized, and the street cabling is the same age except in a couple of places where the consac has gone bang and 6 foot lengths of plastic clad CNE between pairs of 'torpedo joints' bypass the blown out bits of SNE.

    The transformer feeding my dad's place however went in during  the mid 1950s, and there is no room to upgrade it if that were ever needed without compulsory purchase of adjacent property or some seriously messy  building work- indeed by current standards of accessibility, it is already too small for the transformer it currently supports. The good news though is that the cable is PILC, not consac, and lead seems to be far more long lived than aluminium.

    Here in town the pre-war houses have TT supplies coming in overhead on singles, and where they have failed, are replaced with concentric cable to the houses and ABC for the street mains. Transformers are an odd mix of H mounted pole pigs and things in brick sheds or ground mount fenced enclosures between buildings... Those transformers are mostly  50-70 years old and in terms of wear, in many cases barring an oil change and a rust inspection, in good shape for the the same duration again into the future.

    (BSEN60076 Part 7, requires transformer insulation to be designed for 180000 hours of service (20.5 years) working at full load current and 98°C hot spot temperature - now the model predicts insulation lifetime doubles (or halves) with a ten degree change - so changes in load and seasonal load, are really critical to lifespan. In reality this is probably not as clear cut.)

    But this situation is far from unique - almost every town in the land has miles of installations like this, and if the load profile is unchanged, it can carry on for many decades yet - and the number of DNO staff and rate of manufacturing of spares and many other things, reflect that pace.

    Mike

Reply
  • I'm thinking V2G may be a way of extending the lifetime of existing infrastructure such that the future investment could be optimised (e.g. prioritised based on the weakest points in the network.)

    quite, but if we only do that at the pace of the current system has developed, then it will take 70-120 years to complete, by which time the goalposts will have moved again.

    Generally the  UK system either dates from when the house was built if post war, or from whenever the pre-war supply (if any) became inadequate for increasing load.

    By way of anecdotal support for my 70-120 year figure.

    I'm not sure how old the transformer that feeds your house is for example. but the one that feeds mine was installed at some point in 1969, and there is an adjacent unused pad for another to take extra load that has never materialized, and the street cabling is the same age except in a couple of places where the consac has gone bang and 6 foot lengths of plastic clad CNE between pairs of 'torpedo joints' bypass the blown out bits of SNE.

    The transformer feeding my dad's place however went in during  the mid 1950s, and there is no room to upgrade it if that were ever needed without compulsory purchase of adjacent property or some seriously messy  building work- indeed by current standards of accessibility, it is already too small for the transformer it currently supports. The good news though is that the cable is PILC, not consac, and lead seems to be far more long lived than aluminium.

    Here in town the pre-war houses have TT supplies coming in overhead on singles, and where they have failed, are replaced with concentric cable to the houses and ABC for the street mains. Transformers are an odd mix of H mounted pole pigs and things in brick sheds or ground mount fenced enclosures between buildings... Those transformers are mostly  50-70 years old and in terms of wear, in many cases barring an oil change and a rust inspection, in good shape for the the same duration again into the future.

    (BSEN60076 Part 7, requires transformer insulation to be designed for 180000 hours of service (20.5 years) working at full load current and 98°C hot spot temperature - now the model predicts insulation lifetime doubles (or halves) with a ten degree change - so changes in load and seasonal load, are really critical to lifespan. In reality this is probably not as clear cut.)

    But this situation is far from unique - almost every town in the land has miles of installations like this, and if the load profile is unchanged, it can carry on for many decades yet - and the number of DNO staff and rate of manufacturing of spares and many other things, reflect that pace.

    Mike

Children
  • Hello Mike:

    When one lives in an area which is prone to have annual hurricanes and tornadoes the power company has active ongoing programs to harden the complete interstructure (example replacing wooden poles with concrete). The local pole based transformers feeding houses in my area only have a life of about 15 years and take less than 2 houses to replace.

    Peter Brooks

  • When one lives in an area which is prone to have annual hurricanes and tornadoes the power company has active ongoing programs to harden the complete interstructure (example replacing wooden poles with concrete). The local pole based transformers feeding houses in my area only have a life of about 15 years and take less than 2 houses to replace.

    When I visited the states I was amazed/bewildered by their system of overheads, even in suburban areas - massive wooden poles but with just about everything hanging off them - HV, LV, phone lines, street lights, road signs, traffic lights the lot all one the same set of poles. Watched one crew replacing a pole which seemed to be done by letting all the cables dangle and lots of careful manoeuvring. I couldn't understand, especially given the extreme weather, why they didn't underground most of it, as is common elsewhere.

       - Andy.

  • Hello Andy:

    When one buys a house and the land on which it stands, one gets a legal drawing showing the external dimensions of the house and it's orientation relative to the boundary of the lot.

    It also shows the power line easement (usually 10 ft from one of the boundary lines).

    If one places a pool on ones property and the power cable would cross over the pool water on its way into the house then the LV line is rerouted from the power pole using an underground cable.

    When repairing the lines the people use special safety blankets draped over the active lines.

    The overhead HV power lines provide a perch for the migrating birds when they fly south to escape the cold fronts this time of the year.

    Peter Brooks

    Palm Bay Florida USA 

     

  • you need to visit the 220V bits of South America for the ultimate in pole re-use and scary wiring generally - North America is a bit of a tangle, but has nothing quite in comparison ! 

    I have somewhere some pics from Brazil with 20kV overhead , 220V/380 3 phase transformers, and 3 phase _ N LV and underslung all manner of telecoms and cable TV cables. 

    Worse the HV is earth-referenced as they make use of Single Wire Earth Return, to isolated farms and so on, so there is no 'big RCD' on the HV, so if an 18kV  line comes down it is probably still live as it hits the ground - unlike the UK, where if an 11 or 33kV line breaks, it usually isn't. (not sure about the USA on this - I think California has neutral free HV, but other regions do not seem to )

    The funniest photos are a couple of chaps leaning bamboo ladders on the LV lines to climb up and work on the telecoms,

    rgds,

    Mike