Electric Cars - A general discussion platform

[Zigzagsky]

Interesting reading, thanks for the links.

[iainfm]

I'm really, really wanting an EV to replace our current cars - I've got two fossil-burners that are sitting idle (they're old but paid for) doing nothing, but I still think I'd save money with an EV once tax and repairs/running costs are taken into account.

I'm completely spoilt for choice at the moment, with new models arriving almost daily. Think it's a bit of a coin-flip between a cheap but utilitarian MG5 or a Kona/e-Niro. Or an Ioniq. Or an ID.3. Or...argh!

Anyway, given EVs are quiiite expensive and I've never had a new car before, what does everyone reckon is the best way to buy them? Lease/PCP/loan/other?

[philb]

I've had my last four EVs on three or four year PCPs. I'm just about to do a 2-year lease for my next one.

[chinnyhill10]

There's no credible case for hydrogen in cars; in buses it's more marginal, but still unconvincing for city buses (as opposed to long-distance). Likewise for rail it mostly doesn't make sense (compared to conventional electrification for long-distance/high-speed, and batteries for shorter distance branches off electrified main lines) but there are some niche applications where it might - the far north line in Scotland is the example most often quoted.

I got to spend a couple of days with a hydrogen bus on trial last year.

The problem with electric is if you have a fleet of 40 buses at a depot, you only have a limited slot to recharge them overnight. Plus you need the power infrastructure to do that. You are potentially talking new substations, extra cables in, etc etc. Or you have to buy a load of extra buses to cover daytime charging, and these are far from cheap.

With hydrogen, you've filled the tank in 10 minutes and potentially you can do this at your own depot. You basically treat them like a conventional bus. It's all very 'business as usual' and operators like that. Especially if a hell of a lot of charging equipment + a power upgrade needs to be installed at a depot but you are on fixed term franchises.

Although what nobody seems to address is if we had millions of hydrogen cars and buses, what impact will all the water they drip from their exhausts have?

[a1exh]

When I charge at home overnight it means I drive at less than 2p per mile compared to 9p I used to pay for my Turbo Diesel.

Have you factored in the taxation on Diesel ?

I suspect not, wait until the Government tax electric vehicles at a comparable rate to dead-dino juice and the cost advantage will disappear and believe me they will do it.

Do you think this could be why they are pushing smart meters? Once every home has a smart meter they will be able to charge a variable rate for electricity at different times of the day based on demand.

[BigEd]

I do think smart meters is about having a smarter grid... and ultimately that might mean different pricing regimes. I remember Economy 7...

When it comes to internet access, I recall that flat-rate pricing was very liberating. Same sort of thing with mobile phones - it feels good to have prepaid minutes because they feel like free minutes. But when it comes to energy consumption, it's better for society if individuals have an awareness of what they are using, and when. So long as it's not a cause of hardship. So I'm cautiously in favour of variable pricing. I can see that it depends on your priorities, values, and concerns.

One of the big things for electric vehicles, I think, is the regenerative braking. That's great for stop-start delivery trucks, and perhaps also for in-city busses.

But yes, charging times, and the grid capacity for charging, is a big deal. A possible partial answer there is batteries that you can swap, so you can have more of those, and be charging during the day too. (Although night time is ideal for charging, because generation goes on, especially wind (and wave, and tidal) whereas industrial and domestic use tails off.)

I wish we'd landed in a place where batteries were standard and swappable and leasable, but we seem to be going in the opposite direction, where the batteries are designed in as structural components. Which saves weight and volume.

[guesser]

Although what nobody seems to address is if we had millions of hydrogen cars and buses, what impact will all the water they drip from their exhausts have?

Roads are usually installed outside and designed to handle large amounts of water falling on them

[BeebMaster]

Mmm, try living round here. 3 drops of rain and the roads are flooded. If the highway planners had any brains they would make the roads concave shaped and have drainage channels running all the way along the sides, instead of the odd grid here and there specifically located to actually miss running water. That's in the case of the few grids round here which aren't chock full up to the top with mud.

[arg]

The problem with electric is if you have a fleet of 40 buses at a depot, you only have a limited slot to recharge them overnight. Plus you need the power infrastructure to do that. You are potentially talking new substations, extra cables in, etc etc. Or you have to buy a load of extra buses to cover daytime charging, and these are far from cheap.

With hydrogen, you've filled the tank in 10 minutes and potentially you can do this at your own depot. You basically treat them like a conventional bus. It's all very 'business as usual' and operators like that. Especially if a hell of a lot of charging equipment + a power upgrade needs to be installed at a depot but you are on fixed term franchises.

Obviously "business as usual" is the sales pitch for hydrogen, but it's not as simple as that.

Hydrogen fuelling kit is big and expensive and not actually that fast (sure, it's quicker than electric charging, but not as quick as pumping diesel). There's usually a 'recovery time' for the pump to prepare for the next fill (pressurising and cooling the hydrogen). This isn't quite as bad for buses that can afford bulkier tanks and only 350bar pressure, compared to cars that need 700bar, but still significant. So you've probably got only one or two filling stations in the depot with say a 15-min cycle time - so your fleet of 40 buses takes 10 hours to fill and hence you probably need a couple of staff on third shift just to cycle the buses through the filling points. Compared to the driver taking 30 seconds to plug in after parking up for the pure electric.

Certainly electrical infrastructure is an issue - but with hydrogen you need three times as much energy if you are making the hydrogen on-site, so the electrical connection is probably even bigger (it would be the same size if you were comparing 24x7 hydrogen generation against overnight charging, but to have any green credentials at all the hydrogen has to be generated when demand is low so you are probably needing a bigger connection for the hydrogen case). Or if you aren't generating it you are trucking it in and need somewhere to store it.

It's conceivable Hydrogen might come out ahead on the capital costs and/or operational considerations for a particular site, but it's far from a sure thing in either of those respects in the general case.

[1024MAK]

I do think smart meters is about having a smarter grid...

Going off topic here, but I don’t see smart meters as helping very much. If you can afford to pay your electricity bill without problem, why are you going to take any notice of what your current electricity consumption is? All it does is add the convenience of not having to read your own meter or let in a meter reader. And it’s likely that even if variable pricing does come in, it won’t affect your usage.

How many people do you think will regularly monitor their smart meter a couple of months after the novelty has worn off? People have far more entertaining distractions to spend their time on.

As to a smarter grid, the National Grid are already very, very good at managing the electricity national distribution network / grid. They already take into account the availability of the power generators, the current demand, the expected/predicted demand (including known peaks caused by certain television programmes) and can cope with the almost random drops in demand caused by PV solar panels as the sun comes out from behind clouds, or the increase when the opposite happens.

A smart meter may make sense if there is a different (cheaper) overnight rate for charging up your electric car. But otherwise, I would rather that the government encourage (including financially) home owners and building owners to super insulate their homes and buildings. And to install more efficient heat source pumps or other efficient heating systems. The aim being to really reduce energy consumption by a substantial amount. Not to tinker around the edges a little, which is all that I see from smart meters. Which of course are not free, as everyone who pays a electricity or gas bill is paying towards.

IMHO smart meters are a gimmick. Even the adverts for them that go on about saving money say ‘requires user action’ or words to that effect, meaning they only save money if you actively try to save using energy by turning appliances off. But you don’t need a smart meter to do that!

As far as I know, battery operated trains are still in the experimental / trial stage. The halt to the various electrification (OHL - overhead line) programmes means instead of more pure electric trains, more bi-mode trains were ordered. These bi-mode are the Hitachi 800 series that have been in the news recently (due to cracks in the metalwork) that have Diesel engines for use when on a line where there is no OHL equipment.

If the government decides to spend money on finishing the current planned OHL sections and on new OHL sections or extending OHL, that makes more sense rather than having trains stuffed full of batteries.

I’m not saying that there is no place for battery powered small trains on branch lines, I just don’t see much likelihood of the fast main line trains becoming battery powered.

Unlike an electric car where you can break your journey in order to boost charge you car battery while you have a coffee, tea or meal break, a train operator would not be popular if a train with hundreds of passengers on board stopped for a recharge for half an hour halfway through its journey...

Mark

[arg]

As to a smarter grid, the National Grid are already very, very good at managing the electricity national distribution network / grid. They already take into account the availability of the power generators, the current demand, the expected/predicted demand (including known peaks caused by certain television programmes) and can cope with the almost random drops in demand caused by PV solar panels as the sun comes out from behind clouds, or the increase when the opposite happens.

Yes, but they are going to have one of their main tools (gas turbine generators that can spin up or down on command) taken away, and demand management is a potentially cheaper way of doing some of it than alternatives such as grid-scale batteries or gross over-building of renewables and discarding the excess power.

That's at the supply end; the distribution end also has a cost trade-off: the average street has just enough distribution capacity for everybody to charge overnight, but not if they all turn on at midnight - the demand needs to be managed, or major reinforcement work required (this is the issue where people think they've got a 60A or 100A supply coming in to their house, but the street is planned on only about 2kW average per house).

IMHO smart meters are a gimmick. Even the adverts for them that go on about saving money say ‘requires user action’ or words to that effect, meaning they only save money if you actively try to save using energy by turning appliances off. But you don’t need a smart meter to do that!

It only makes sense if the appliances do it automatically. I wouldn't disagree with you branding the current Smart Meters as a gimmick; at best they are a small (and expensive) step in the direction we need to go.

I’m not saying that there is no place for battery powered small trains on branch lines, I just don’t see much likelihood of the fast main line trains becoming battery powered.

That appears to be the general industry view - batteries for short branches or 'difficult bits' (like the battery trams bought to avoid wiring Birmingham city centre), but no alternative to traditional electrification for long distance. Hydrogen possibly an option for very remote places too long for batteries and too infrequent for electrification to pay off.

Unfortunately, Government seems to keep hoping for some magic new technology that's going to make it all easier, rather than take the hard decisions.

[1024MAK]

... the National Grid are already very, very good at managing the electricity national distribution network / grid...

Yes, but they are going to have one of their main tools (gas turbine generators that can spin up or down on command) taken away, and demand management is a potentially cheaper way of doing some of it than alternatives such as grid-scale batteries or gross over-building of renewables and discarding the excess power.

As the CCGT are taken out of use, yes, this will make it a lot harder. And the current pumped storage hydro-electric stations also will not be enough. On the plus side, if we do happen to have an excess of wind power, some of the wind turbines can feather their blades to reduce output. And building more interconnect power links (including more powerful ones) between different countries may also help a bit. Especially if it’s windy in one area but not in another. The biggest problem, is if it’s not windy anywhere across the many wind farms and there is no sun either...

If we, as a country, can continue the existing trend of a reduction of our overall electricity consumption, then that also will make it easier. Especially if we can speed up our reduction of power usage.

And of course, this process of changing how we get our electricity will be gradual, just as it has been over the last ten to twenty years, giving time for hopefully the people and the system to be able to adapt and cope.

That's at the supply end; the distribution end also has a cost trade-off: the average street has just enough distribution capacity for everybody to charge overnight, but not if they all turn on at midnight - the demand needs to be managed, or major reinforcement work required (this is the issue where people think they've got a 60A or 100A supply coming in to their house, but the street is planned on only about 2kW average per house).

The current (sorry!) power diversity arrangements of the existing sub-stations, local feeders and indeed the distribution network will eventually have to be addressed. But not everyone is going to have an electric car all at once, and not every electric car will be be needing a full charge overnight (or at any time for that matter). And again, it will be a gradual change. I don’t have a problem if the electric car charging systems are semi-intelligent or are partly controlled by the available power available from the electricity supply system.

I don’t have an electric car (I have a hybrid), but as I’m a shift worker, if it’s sunny, I’m more likely to want to use power from my PV solar system to at least partly charge any electric car I get.

... smart meters ...

It only makes sense if the appliances do it automatically. I wouldn't disagree with you branding the current Smart Meters as a gimmick; at best they are a small (and expensive) step in the direction we need to go.

Yes, I see a future in semi-intelligent appliances, a dish washer, washing machine, water heater or similar turning on when there is a surplus of wind or PV solar power for example.

Mark

[Marvin]

When I charge at home overnight it means I drive at less than 2p per mile compared to 9p I used to pay for my Turbo Diesel.

Have you factored in the taxation on Diesel ?

I suspect not, wait until the Government tax electric vehicles at a comparable rate to dead-dino juice and the cost advantage will disappear and believe me they will do it.

Do you think this could be why they are pushing smart meters? Once every home has a smart meter they will be able to charge a variable rate for electricity at different times of the day based on demand.

I suspect that smart meters will end up talking to your electric car charger and billing you accordingly, i.e. 20p per kilowatt for general household use and £2 per kilowatt to charge your car.

As the old saying goes only 2 things in life are certain... death and taxes. Sure the early adopters will effectively get a tax break for awhile and enjoy cheaper motoring but sooner or later the government will come looking for their missing taxes, it's the nature of the beast and no technology will ever change that.

Let's just say I'm rich (I'm not) so I go off grid by installing a big wind turbine, lots of solar panels and a huge battery storage system. Then I plug in my electric car to my system and enjoy effectively free motoring... until enough of us do it and the government realises they are loosing all that tax money and insist we all have GPS trackers fitted to our cars to monitor usage and bill us accordingly.

[a1exh]

It would explain why the Gov are looking to introduce a replacement for VED which would be pay per mile using a smart black box device in all cars. I had wondered why go to all that trouble? Surely just tax the fuel and you ARE taxing per mile but if we're all driving electric cars...

[philb]

I suspect that smart meters will end up talking to your electric car charger and billing you accordingly, i.e. 20p per kilowatt for general household use and £2 per kilowatt to charge your car.

They could do that, but it would end up being a horrible mess because meters bill (essentially) for net consumption and units of electricity are completely fungible (unlike, say, the situation with red diesel). If the price differential between general electricity and "motor vehicle" electricity was that steep, you'd end up with arbitrage schemes where people would charge a battery from the grid and then use the battery and/or their local solar PV to charge their car.

If the object of the exercise is just to charge an extra levy per kWh of energy used to run a car, you don't technically need the smart meter to be involved at all: the majority of installed EVSE is already at least a bit smart (including its own data connection) and it would be easier to just have the EVSE report consumption data directly without the main house meter having to do anything. But this in turn would create an incentive for people to use non-smart EVSE (e.g. portable charge cables) which probably isn't what you want. You could fix that with primary legislation to outlaw charging via anything other than approved EVSE, but that would be quite a brave step and there'd need to be provision for the current installed base of equipment.

Also, there would be (probably) unintended consequences from any such scheme though in the form of probably killing off the "free-to-use" chargepoints in supermarkets, office parks and places like that. There are plenty of businesses that are currently happy to eat the fairly trivial cost of the electricity, which vanishes in their general overheads, but for whom a £2/kWh surcharge would be hard to swallow.

So I agree with the general point that the government is going to want to maintain its overall tax take, but I'm not so sure that they will do this by simply transposing fuel duty from petrol and diesel directly onto electricity. I think it's more likely we will end up with either a "pay as you drive" road metering scheme, as you suggested later in your post, or that they will give up on the idea of usage-based road taxation and just make up for it with an increase in VAT or some other general taxation.

[BigEd]

Some diagrams on this page about 'demand side response' which means a household automatically or manually adjusting load according to information from the grid:
https://www.smartme.co.uk/load-control.html

If many homes have EVs charging overnight, and they don't all need a full eight hours of charging, it makes sense for them to be sequenced under some kind of negotiated or centralised control.

(It's another thing about EVs which is difficult for me to understand how to make best use of: it's not optimal to run from full charge to empty, either in time or battery life. An EV should only be charged to full in anticipation of needing all the range, and should only be run to empty in case of need. I suppose we need to tell our cars when we expect to need them, and how much distance we expect to ask of them in the next journey. It's almost like thinking ahead brings benefits!)

[philb]

(It's another thing about EVs which is difficult for me to understand how to make best use of: it's not optimal to run from full charge to empty, either in time or battery life. An EV should only be charged to full in anticipation of needing all the range, and should only be run to empty in case of need. I suppose we need to tell our cars when we expect to need them, and how much distance we expect to ask of them in the next journey. It's almost like thinking ahead brings benefits!)

Although that's true, I think this is probably a level of optimisation too far for most people in the short term. Most current EVs can't be charged to 100% anyway because the BMS imposes a headroom limit, and in that case it's essentially safe to keep them topped up all the time. I've never really paid all that much attention to my charging patterns and in the seven years or so that I've owned EVs I don't think I've noticed any significant battery degradation. If you're charging overnight anyway then of course the time element isn't very important.

I only have one chargepoint for two cars so my MO tends to be that I charge each car whenever its indicated mileage starts to look a bit low for the journeys I plan to do the following day. In pre-COVID times that generally meant charging one car each night and alternating them, though more recently it's been probably once a week for each.

I think you're probably right that we will start to see EV charging treated as a dispensable load for the purposes of demand-side management and I wouldn't be at all surprised if within a few years we are in a situation where the DNO can interrupt or defer your charge session for an hour or so if that helps them to manage their distribution network better. And of course, as time goes on, the same will probably start to apply to more and more white goods, so your smart freezer might try to get itself especially cold by about 3pm and then basically do nothing until the evening peak starts to level off. Likewise it might be that the default "eco" mode on your smart dishwasher is to not start until grid demand is below a certain level and falling.

[guesser]

You could fix that with primary legislation to outlaw charging via anything other than approved EVSE, but that would be quite a brave step and there'd need to be provision for the current installed base of equipment.

It would be easier to have the cars report how much energy they've used. Either wirelessly, or downloaded at an annual inspection in the same way the yearly mileage is recorded now.
That would mean the tax would be a year in arrears rather than upfront of course unless they estimated it based on the previous amount.

Though it's going to correlate strongly with miles travelled anyway and you could probably come up with some kind of tax classes based on the size/efficiency of the vehicle.

[philb]

It would be easier to have the cars report how much energy they've used. Either wirelessly, or downloaded at an annual inspection in the same way the yearly mileage is recorded now.

True. Of course, a lot of owners never do an annual inspection, but you could also change the rules to make it so they did.

[philb]

And yes, to echo earlier comments, the biggest lever that the TNO has to pull today is dispatching CCGT capacity. You can see fairly clearly from the "generation by fuel type" graph that Elexon produce (https://www.bmreports.com/bmrs/?q=eds/main) that the difference between the night-time trough and the evening peak is almost entirely covered at present by adding about 12GW of gas turbine.

The second biggest source of voluntary change in there is the France interconnect. Beyond that, it starts to get into things that are either uncontrollable (wind, solar) or take longer to come on line (biomass). Of course biomass can be pre-scheduled to some extent, but it still isn't capable of going from zero to full load in the time that a gas turbine can. So, with CCGTs going away, NGT are presumably going to be looking at ways of flattening that big peak.

[philb]

Hilariously, this today from Instavolt: https://instavolt.co.uk/instavolt-ceo-i ... -may-2021/

Though I think they're being ever so slightly disingenuous there.

[Coeus]

It would explain why the Gov are looking to introduce a replacement for VED which would be pay per mile using a smart black box device in all cars. I had wondered why go to all that trouble? Surely just tax the fuel and you ARE taxing per mile but if we're all driving electric cars...

Long before EVs took off, it seemed to me that scrapping VED and collecting the equivalent amount of money from fuel duty would be a good idea. It would have the twin advantages that the fuel duty is harder to evade and that those who who did a higher mileage would have a greater incentive to drive something less thirsty.

At the time, though, the change to using ANPR and central databases for insurance and MOT had not happened and it seems the police found that questioning people with no tax disc displayed often revealed other crimes both related and unrelated.

But that idea doesn't work so well with EVs.

[Coeus]

I wish we'd landed in a place where batteries were standard and swappable and leasable, but we seem to be going in the opposite direction, where the batteries are designed in as structural components. Which saves weight and volume.

Which also helps ensure obsolescence.

[Coeus]

Unlike an electric car where you can break your journey in order to boost charge you car battery while you have a coffee, tea or meal break, a train operator would not be popular if a train with hundreds of passengers on board stopped for a recharge for half an hour halfway through its journey...

Could you not just swap locomotive? That still doesn't make it a good idea if it is less energy efficient. I think the real answer is to put what capital is available into extending the reach OHL and worry much less about shaving a few minutes off Birmingham to London.

[arg]

Long before EVs took off, it seemed to me that scrapping VED and collecting the equivalent amount of money from fuel duty would be a good idea. It would have the twin advantages that the fuel duty is harder to evade and that those who who did a higher mileage would have a greater incentive to drive something less thirsty.

There's also a need to make it variable - currently you have the stand-off between the green lobby calling for higher fuel duty to encourage people onto public transport, and the rural lobby saying there's no public transport in rural areas so higher fuel duty penalises them unfairly.

Pay-as-you-drive with a variable rate (linked to level of congestion) solves that problem.

And I wouldn't be surprised to see it collected via ANPR rather than black boxes.

[Coeus]

...And to install more efficient heat source pumps or other efficient heating systems....

I wonder how this will affect how much people will pay for heating. The figure I had heard for heat pumps was 1:4, i.e. each unit of electricity consumed moves four units of heat. At the moment, for most people, 1 unit of day rate electricity will cost more than four units of gas which hardly incentivises people to install them.

[1024MAK]

Unlike an electric car where you can break your journey in order to boost charge you car battery while you have a coffee, tea or meal break, a train operator would not be popular if a train with hundreds of passengers on board stopped for a recharge for half an hour halfway through its journey...

Could you not just swap locomotive? That still doesn't make it a good idea if it is less energy efficient. I think the real answer is to put what capital is available into extending the reach OHL and worry much less about shaving a few minutes off Birmingham to London.

Most new trains these days are a form of multiple unit. There is no locomotive, the drive motors and engines are under and part of the passenger carriages. For example the Hitachi 800 series (that includes electric/diesel bi-mode types) that has been in the news recently is like this, with cabs on the front and rear units. So you would have to terminate the service and everyone would have to get out and walk across to another train.

Modern thinking is to use bi-mode trains, then there is no need to change from one type of locomotive to another or for it to run round the train at the terminal station. Changing locomotives means having to have staff available to carry out the uncoupling and coupling operation. Plus the track and signalling has to be set up for the shunting moves needed. Over the years, these facilities have often been designed out as the railways have adapted to a busier more intense timetable.

The Hitachi 800 bi-modes can switch from OHL electric operation to diesel without having to stop. Or switch from diesel to electric without having to stop.

However, if you go for a bi-mode OHL electric and battery powered train, do you really want to drag the batteries along on the journey when running from the OHL electric system? It’s bad enough the 800 series lugging the weight of diesel engines and diesel fuel when under the OHL wires... And based on current battery technology, you would need lots and lots of battery capacity for a heavy train to run at a fast speed.

...And to install more efficient heat source pumps or other efficient heating systems....

I wonder how this will affect how much people will pay for heating. The figure I had heard for heat pumps was 1:4, i.e. each unit of electricity consumed moves four units of heat. At the moment, for most people, 1 unit of day rate electricity will cost more than four units of gas which hardly incentivises people to install them.

For heat pumps, it depends on the actual system that is installed and the temperatures of both the source (underground or external air) and the temperature that you want your home to be heated to.

Basically they work like a fridge or freezer, except instead of cooling the enclosed space and producing unwanted heat, they take heat from the outside environment (and in so doing slightly cool said environment) and then disperse the heat in the enclosed space (the room/house/building). You can already buy air conditioning systems that can do this. But these become less effective as the external air temperature falls below ten degrees below the wanted inside temperature.

Ground source heat pumps can do much better because the temperature underground has a very long thermal lag. The ground warms during summer, and takes many months to cool any significant amount. By which time it’s summer again. So as long as the area used for the pipes is large area compared to the area of your home/building that you want to heat, a well designed system should work well. The biggest drawbacks are, you obviously need a suitable area of ground to dig up to install all the pipes. And they are rather expensive to install.

Hence my preference is for homes and buildings to be super insulated. If hardly any heat can escape, you don’t need much in the way of heating.

Mark

[BigEd]

I read a fascinating snippet in the wikipedia entry for CCGT as mentioned upthread (meaning Combined cycle gas turbine, being an arrangement to extract the most useful energy from the fuel.) And the snippet was this: if the situation is that the generator produces excess energy at some times which is useful to store for other times, one way is to use the energy to make ice, and then later use the ice to pre-chill the intake of air to densify it.

On reflection it makes sense, but on the face of it making ice as a way to store energy feels somewhat unexpected.

Edit: another nice snippet, about the high temperatures that the turbine blades are exposed to being a limiting factor, and how a coolant in channels within the blades can help, and how one popular coolant is steam. Yes, steam as a coolant.

[philb]

...And to install more efficient heat source pumps or other efficient heating systems....

I wonder how this will affect how much people will pay for heating. The figure I had heard for heat pumps was 1:4, i.e. each unit of electricity consumed moves four units of heat. At the moment, for most people, 1 unit of day rate electricity will cost more than four units of gas which hardly incentivises people to install them.

Well, arguably the right answer to that is to insulate your buildings so you need less heat in the first place.

It's also worth remembering that most gas boilers are rather less than 100% efficient, whereas a heat pump is very close to 100% efficient (if you're using it for heating, anyway). A modern condensing boiler might be 90% efficient when it's actually condensing, but a lot of them are installed such that they don't condense very much of the time. It's probably still true that mains gas is cheaper, but I suspect this narrows the margin somewhat.

And, returning to smart meters further up the thread, if you have off-peak energy pricing then you can run your heat pump mostly when electricity is cheap. That requires you to have sufficient thermal mass or a place to store the heat in the meantime, of course, but it's doable.

Finally of course, new gas boiler installations are simply going to be prohibited in the fairly near future so that will be removed as an option and in a sense it doesn't matter what the price of gas is at that point.

[Coeus]

And, returning to smart meters further up the thread, if you have off-peak energy pricing then you can run your heat pump mostly when electricity is cheap. That requires you to have sufficient thermal mass or a place to store the heat in the meantime, of course, but it's doable.

And this is precisely the problem. At the moment people prefer their houses to be warmer in the day and cooler at night which works against using electricity when there is a surplus. It seems to me heat pumps would be ideally coupled with heating the house overnight and then having sufficiently good insulation that sufficiently little heat leaks out during the day that topping up is minimal if at all.

Perhaps our preference over temperatures is historic when people snuggled under blankets or a duvet because the fire would go out overnight. Maybe people would get used to sleeping with much lighter bedclothes but wearing a jumper in the evening when the heat from the previous night is at its lowest..