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Electric vehicles – will they break the system?

By Dave Elliott

Much has been said recently about electric vehicles (EVs) – they are on the way in large numbers, we are told. The Carbon Tracker/Grantham Institute report (see my earlier post) says that, by 2050, EVs will account for over two-thirds of the road transport market globally. That could change the transport system dramatically, although that alone won’t stop congestion. Unless we also move to autonomous cars and taxis, which should use road capacity more efficiently, we will just have queues of EVs – and continued pressure for more road building. But it could change the energy system. Not just in terms of replacing fossil fuels, but also in terms of changing and challenging the emergent non-fossil energy supply system.

An early study suggested that the widespread adoption of EVs could lead to a 20% rise in power demand – energy now supplied by fossil fuels directly would have to be supplied by electricity generation plants. There would, of course, be major emission savings if these were non-fossil plants. That is clearly the aim. The Carbon Tracker/Grantham report, which focuses on PV solar, looks to a progressive decarbonisation, with solar supplying 39% of electricity globally by 2050 and other renewables (along with nuclear) also making large contributions. It adds that the synergy between EVs as storage options and renewable power could further drive the simultaneous roll out of the two’. The connection there is via the vehicle-to-grid idea, with EV batteries being used, when linked to the grid, to balance variations in renewable availability and grid power demand.

However, the wide adoption of EVs would have some other important implications for the power system. There would not just be a need for more power stations, but also a need for better grid links to deal with the increased demand. At present, about 40% of overall UK energy demand comes from transport. Trains and a few EVs and biogas buses apart, it is almost entirely met using fossil fuel. If all vehicles were EVs, although they are more efficient energy users, the power demand would be significant and, more importantly, occur (for charging) mostly at what is already a peak demand time – in the evening.

The power generation system, whatever types of capacity it used, and the national and local distribution grids might not be able to cope if everyone plugged in their EVs to recharge them at around the same time at the end of the working day. Arrangements could be made to stagger this, via smart grid variable pricing, and some may well be charged at other times and locations e.g. during the day at work or at retail centres, but the scale, location and timing of the demand is still a big issue. Though it can be overstated. The Times ran a story (11/2/17) saying the UK would need 20 new nuclear power stations to cope!  That was soon challenged and an apology printed (15/2/17). Electric cars would need nowhere near as much as that: see John Prentice’s letter to The Times on 16.2.17. National Grid came out with the perhaps reasonable figure of 6 GW or maybe 8 GW by 2030. And the debate was put in context by Carbon Brief.

Even so, as it noted, there will be extra power demand if EVs boom – maybe 10% by 2050 according to Cambridge Econometrics. The initial article in The Times pointed to data produced by Transport for London (TfL) which it said suggested that ‘switching to an all-electric vehicle fleet in the capital would demand five times the amount of power needed to run the entire London Underground network’. That highlights the valid point that we ought to be using electricity for public transport, not for cars. And perhaps also be looking to alternatives to EV for the remaining cars. Certainly, that last point has been made by those seeking to challenge the UK drive to low carbon electrification (with nuclear, along with offshore wind) of all things – heating as well as transport: it couldn’t all be done with the existing grid as it isn’t big enough. Instead, green gas enthusiasts argue that storable biogas and syngas, including green hydrogen, could help with both heat and transport, and could be distributed via the existing gas mains, which already handles 3-4 times more energy than the electric power grid.

For transport, biogas/syngas trucks and vans, and maybe buses, as well as agricultural vehicles using biogas made on farms, seem to make sense. However, there are limits to how much biogas can be produced and some also look to hydrogen-powered cars, using green hydrogen made from surplus wind/PV derived electricity, although the power would initially involve grid transmission. Unless the green hydrogen was made with local wind or PV near service stations and stored there, or distributed via gas grids. It is conceivable that domestic ‘prosumers’ could make their own hydrogen, or power, using roof-top PV, for use in their cars, although that would require a lot of home storage, on top of any they needed to balance their day-time PV inputs with their other night-time energy uses.

However, as larger scale renewables expand, hydrogen production and distribution may also expand, to aid balancing and avoid curtailment. Interestingly, in this context, National Grid sees green hydrogen possibly playing a large role in transport, more, in one high renewables scenario, than EVs. Some progress has already been made. And some think hydrogen cars might one day catch up with EVs. But then some say hydrogen has limits as a vehicle fuel.

Overall, EVs are still winning, but there is still a way to go. Green cars? Yes, soon, but where does the power come from and how does it get to you? And is this really the best use for wind and solar power?  Wouldn’t it be better to to support public transport systems more, powered by renewables including non-grid and/or non-electric renewables?

There are already several train networks using (mostly) wind power from the grid. Though see this. But other options are possible, including trains using hydrogen, which could come from biomass or wind-to-gas plants. Or trams or trains run on solar energy, or on a mixture of solar and wind.

Private EVs are not the only way ahead, though they do have a place, since we all (mostly) still love to drive and, for many in rural areas, cars are the only mobility option and battery EVs are one way to provide it. For an optimistic take on electric cars, and much else, see Tony Seba’s book ‘Clean Disruption of Energy and Transportation’ and this presentation. Seba says that, with battery costs falling fast, by 2030 all new vehicles will be electric. And on the impact of autonomous cars, see this from Ben Evans but also this Business Insider article.

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