Advisability of buying electric car at this point in time

ComicGeek

Martyn1981 said:

Ectophile said:

While the National Grid are happy that they have enough capacity, it's the local power networks that are going to be the problem.  Particularly that last few hundred yards from your local transformer to your home.

For many years, it's been assumed that a house that isn't heated by electricity will use about 2kW when averaged over a day.  So if you're building an estate of 100 houses, all with gas boilers, then you need 200kW of transformers to supply the estate.

But an electric car on a home charger can draw 7kW for several hours.  And it will be even worse when gas boilers are banned and we start switching to electrically powered heat pumps.

But the DNOs (District Network Operators) are doing what privatised utilities usually do: nothing, until something goes wrong.  Then they patch things up when they break.

I don't think that's correct. The existing set up is capable of providing enough power for power showers (7-10kW), or for electric space heating via resistive heating*. So they can manage high continuous load already. Homes will have 60A - 100A main fuses, which equates to about 14kW to 23kW.

That's based on diversity though, with the DNO rightly assuming that not everyone in your street is running high electrical loads at the same time. I know that our 30 yr old estate is based on an average 4 kVA (3.4 kW) per property for gas heating, whereas modern estates use the 2-3 kVA figure. Each house may have the capacity to run at high load, but the local transformer can't cope if everyone starts doing it - that's why you have to make DNO applications for PV, battery, EV chargers and heat pump installations so that they can monitor the local situations, and why it's not helpful when people avoid making applications.

So nomal baseline usage for a gas heated house is going to be 100-300W - there are then spikes in load when people use appliances. The gamble by the DNOs is that there is sufficient diversity across houses (and the larger the area served the greater diversity is applied) to even out the spikes.

Random time delays are included on all new EV chargers now to prevent them all starting at the same time in peak periods. That is one way that they are trying to control peak load demand. But if everyone in the street owns an EV then they can't allow everyone to start charging at 7kW at 11.30pm each night on a IO tariff - that's when smart charging plays a key part, sharing the available capacity across multiple households and preferably across the full 24hrs. I expect that there will be staggered off peak periods across a local area.

The problem is that it needs full cooperation between DNOs, energy supply companies and home owners - but hardly an industry that's fully trusted by home owners, just look at the issues surrounding the smart meter rollout!

MattMattMattUK

Ectophile said:

While the National Grid are happy that they have enough capacity, it's the local power networks that are going to be the problem.  Particularly that last few hundred yards from your local transformer to your home.

For many years, it's been assumed that a house that isn't heated by electricity will use about 2kW when averaged over a day.  So if you're building an estate of 100 houses, all with gas boilers, then you need 200kW of transformers to supply the estate.

But an electric car on a home charger can draw 7kW for several hours.  And it will be even worse when gas boilers are banned and we start switching to electrically powered heat pumps.

But the DNOs (District Network Operators) are doing what privatised utilities usually do: nothing, until something goes wrong.  Then they patch things up when they break.

Can you imagine the tantrums that people would have if they were told that energy bills were going up so that DNOs could invest in installing larger capacity within the network for the benefit of EV users and those with heat pumps? The tantrums would be so large you might see veins in their foreheads explode. 

This would be spun in certain segments of the media that are very influential with those of lower intelligence as a "green tax" or "tax on the poor, to pay for rich people's toys", when the reality is we all need to decarbonise as much as possible. There is no way the upgrades will happen until parts of the grid start to fail under the load, because our political climate and the many climate change deniers that still exist within the general public mean that a rational approach is very difficult for a government of any kind to take, even if it had the will initially. 

ComicGeek

MattMattMattUK said:

Ectophile said:

While the National Grid are happy that they have enough capacity, it's the local power networks that are going to be the problem.  Particularly that last few hundred yards from your local transformer to your home.

For many years, it's been assumed that a house that isn't heated by electricity will use about 2kW when averaged over a day.  So if you're building an estate of 100 houses, all with gas boilers, then you need 200kW of transformers to supply the estate.

But an electric car on a home charger can draw 7kW for several hours.  And it will be even worse when gas boilers are banned and we start switching to electrically powered heat pumps.

But the DNOs (District Network Operators) are doing what privatised utilities usually do: nothing, until something goes wrong.  Then they patch things up when they break.

Can you imagine the tantrums that people would have if they were told that energy bills were going up so that DNOs could invest in installing larger capacity within the network for the benefit of EV users and those with heat pumps? The tantrums would be so large you might see veins in their foreheads explode. 

This would be spun in certain segments of the media that are very influential with those of lower intelligence as a "green tax" or "tax on the poor, to pay for rich people's toys", when the reality is we all need to decarbonise as much as possible. There is no way the upgrades will happen until parts of the grid start to fail under the load, because our political climate and the many climate change deniers that still exist within the general public mean that a rational approach is very difficult for a government of any kind to take, even if it had the will initially. 

As you are supposed to apply to the DNO for installing EV chargers, heat pumps, PV etc, some applicants are already being charged extra to strengthen the existing network. Not increased energy bills but up front single costs. The DNOs are undertaking a holistic overhaul of the local infrastructure to prepare for the future, but only a limited solution to that one property upgrade application - the cost of doing this piecemeal per property is huge compared to dealing with the local infrastructure in one go.

Those who get in early in a built up area might get away with zero or limited charges. Those whose wait until the current capacity is gobbled up will be hit with large charges. The question is whether individuals will be forced to pay those charges, whether DNOs will be forced to pay and recover via energy bills via the energy suppliers, or whether government will fund it. The mess of the current national energy strategy means critical questions like this remain unknown.

born_again

MX5huggy said:

born_again said:

daveyjp said:

All down to budget.  There still aren't many used and £18-20k looks to be the market value for something about 3 years old (Hyundai Kona, Kia Soul EV).

If you pay £12k for a used petrol the ££8k saved buys a lot of tankfuls and depreciation on a £12k car will be lower.

Perhaps have a look.
That is the price range I'm looking at 
There are Electric (3,610) on autotrader. Many of these 2 years old.

£24K is looking at getting me a 72 plate  ex demo with just over 1K miles.

Car I'm looking at will cost £8.82 to charge from 0 to 100% @.07p kWh which will cover at least 150 miles.

Best I have had out of current ICE was 433 miles @ £47.94.

So 3 x £8.82 gives me a saving of £20.77

Your EV maths is a bit out, it’s better than that. Not sure where you’re get 7p a kWh so I’ll change to 7.5p (Octopus Intelligent). Depending on and how you drive the car but you can expect 3.5 miles per kWh so fuel cost is 2.14p per mile so 433miles costs £9,28.

You won’t be buying an EV with a battery big enough to put £8.82 of 7.5p per kWh electricity in in one go. That would be a 120kWh battery. Most EV’s are in the 40 to 80 sort of range for battery size. 

Thanks for that 😍

Even more weight to my argument 

I have a choice of either e-c4 with a 50kWh (42kWh usable) or a Mg 5 61.1 kWh

Decisions Decisions 🤷‍♀️

Martyn1981

Goudy said:

My maths was based on a currently available BEV HGV tractor unit and not something that isn't yet available.

The eActros 300 from Mercedes has a range of around 330km on a full charge.
It can charge from 20% to 80% in 90 minutes on a 160kw charger.

So 90 minutes for 60% charge is around 200km, but to be fair we can to add some of the retaining 20% which obviously needs replacing at a later recharge which would take even longer on a charger.

Current regs for HGVs aren't simple, but it's around 4.5 hours with a 15 minute break (4.5 x 56 mph is 252 miles max range) but with the current crop of BEV HGVs, we're now on 3.5 hours with a 90 minute break for only 196 miles.

Fuel isn't the only factor when costing out road freight like this.
There's obviously the cost of the equipment and the drivers time to consider. 

The current UK weight limit for a 6 axle HGV is 44000kg.
The US limit is nearly 20% less at 36000kg, but that depends on what state it's in, some are actually lower than that.
Would the yet to be available Tesla Semi's range reduce by 20% with 20% more weight, no.

BEV become less and less efficient the heavier they get but the Tesla Semi would have to have at least 20% better range for a similar load than what's on the market now and charge much much faster, even when you factor in the fuel cost savings.

BTW, the Toyota Mirai's (hydrogen car) battery is only 1.2 kw. Hardly large, it's similar to most hybrids.
What's the size of a Tesla battery, 50, 60 or more kw?

Hi, the Tesla semi is currently available. I appreciate that the scale is small, but both Pepsi and Tesla themselves are now running small fleets of them. Since you seem to be looking into the future regarding road transport, then we should of course look to what is possibloe today, and tomorrow. Range of BEV trucks will increase, substantially, expect many to emulate the range of the Tesla, as they need to stay competitive.

Your charge times are also a bit misleading. Yes I agree that many of the current trucks charge relatively slowly, but that's not a future problem. For instance you mention a charging speed of 160kW. But Tesla cars can already charge at 250kW (0-30%) and 200kW (30-50%) and sliding down towards 100kW as they approach 80% SOC.

With a battery 2x, 5x 10x larger, then the charge limits can rise proportionately as the limitations are the chemical basis of the batts, and how hot they get. Again, referring to Tesla, their semi chargers appear to be around 1MW. No reason why a truck with a small battery size of say just 200kWh, won't be able to charge at roughly 3 to 4x the rate of a BEV car with 50-70kWh of batteries. So I think you are confusing the relatively poor charging rates being designed by legacy truck makers, with what is actually possible, and already proven.

Correct the cost of the fuel isn't the only factor, but it is a major one. There's also the considerable cost of maintaining and servicing a large diesel engine and the accompanying components, whereas a BEV is far, far simpler. You even need to consider issues such as down time for the regular oil and air minor service for an ICE truck, and the considerable savings in brake wear for a BEV. So the TCO (total cost of ownership) for a BEV truck will be lower than that for a diesel. Effectively the exact opposite of what you suggested.

Your weight limits ignore the BEV 'bump' that I've already given (assuming the UK follows the EU change). That increase will account for much of the weight increase for the BEV tractor v's an ICE. But, as already explained, most loads aren't weight limited, and battery weights continue to fall.

Yes, a BEV gets less efficient as it gets heavier, as does a diesel truck (does it not?). But the diesel truck is always inefficient, converting about 40% of the energy from the diesel into motive power, when running efficiently at the rpm sweet spot. Obviously at low speeds, the efficiency is much, much worse, requiring upto 16 gears to move the vehicle, and attempt to keep the revs at their most efficient level. Whereas an electric motor has peak torque from zero rpms.

[The vast majority of BEV cars are single speed, no need for gears other than the fixed reduction gear to reduce the motor rpms down. For large BEV trucks, they may have more gears, I seem to recall that Tesla were going to have a two speed system, but now they've mentioned that the truck will have three motors, each roughly the power of a diesel. Running mainly on one motor, but the other two for low speeds, hard acceleration, or steep climbs.]

Yes, a heavier BEV will use more energy to reach cruising speed, than a lighter BEV, but maintaining speed for  identical vehicles, but with different weight, uses roughly the same energy, as the losses are due to drag/rolling resistance (not weight). Also, of course, when slowing the BEV can regen much of that kinetic energy, whereas the ICE will have to waste it in heat and brake pad wear.

BTW, the Mirai has three H2 fuel tanks, so weighing in at about 300kg. With current batteries having an energy density of about 200-240Wh/kg, those tanks are equal to the weight of approx 60kWh of batteries. Obviously the Mirai is driven by electric motors (it's really a BEV with a small battery plus range extender H2 system on board), so the H2 and batts roughly equal out, but you also have to consider the weight of the H2 FCS (fuel cell stack). Hence why it weighs in at 1,900kg.

As I mentioned before, H2 for road transport is already largely a busted flush, due to so many issues, such as efficiency, fuel cost, and again being tied to buying fuel from a fuel station rather than home charging. The Mirai has been out for about 9yrs, and sold approx 22,000 units. BEV car sales are rapidly approaching 1m per month.

Martyn1981

ComicGeek said:

Martyn1981 said:

Ectophile said:

While the National Grid are happy that they have enough capacity, it's the local power networks that are going to be the problem.  Particularly that last few hundred yards from your local transformer to your home.

For many years, it's been assumed that a house that isn't heated by electricity will use about 2kW when averaged over a day.  So if you're building an estate of 100 houses, all with gas boilers, then you need 200kW of transformers to supply the estate.

But an electric car on a home charger can draw 7kW for several hours.  And it will be even worse when gas boilers are banned and we start switching to electrically powered heat pumps.

But the DNOs (District Network Operators) are doing what privatised utilities usually do: nothing, until something goes wrong.  Then they patch things up when they break.

I don't think that's correct. The existing set up is capable of providing enough power for power showers (7-10kW), or for electric space heating via resistive heating*. So they can manage high continuous load already. Homes will have 60A - 100A main fuses, which equates to about 14kW to 23kW.

That's based on diversity though, with the DNO rightly assuming that not everyone in your street is running high electrical loads at the same time. I know that our 30 yr old estate is based on an average 4 kVA (3.4 kW) per property for gas heating, whereas modern estates use the 2-3 kVA figure. Each house may have the capacity to run at high load, but the local transformer can't cope if everyone starts doing it - that's why you have to make DNO applications for PV, battery, EV chargers and heat pump installations so that they can monitor the local situations, and why it's not helpful when people avoid making applications.

So nomal baseline usage for a gas heated house is going to be 100-300W - there are then spikes in load when people use appliances. The gamble by the DNOs is that there is sufficient diversity across houses (and the larger the area served the greater diversity is applied) to even out the spikes.

Random time delays are included on all new EV chargers now to prevent them all starting at the same time in peak periods. That is one way that they are trying to control peak load demand. But if everyone in the street owns an EV then they can't allow everyone to start charging at 7kW at 11.30pm each night on a IO tariff - that's when smart charging plays a key part, sharing the available capacity across multiple households and preferably across the full 24hrs. I expect that there will be staggered off peak periods across a local area.

The problem is that it needs full cooperation between DNOs, energy supply companies and home owners - but hardly an industry that's fully trusted by home owners, just look at the issues surrounding the smart meter rollout!

Hi, sorry quick point. You refer to baseload for your comparison, but you really need to compare to the evening peak load, as that better reflects what the local network can manage (4pm to 8pm, with highest demand 5pm to 7pm). The averaged demand for BEV charging will be less than that.

But yes, you are spot on, all chargers have to be 'smart' so their supply can be dialled down if necessary, and I'd also expect a variety of cheap rate times and deals. A single 7hr charge per week (at 7kW), would be roughly equal to the average weekly mileage of UK drivers. Even over a single local sub-station of about 150 properties, we should be able to rely on averaging, but if necessary those chargers can spread the load more evenly. I share your thoughts about everyone plugging in, and charging at 7kW, but I assume that most of the vehicles won't need to charge for long (again based on averages), hence the need to dial down the power at first, till demand from charged BEV's starts to 'drop off'.


Edit - Sorry, should have said (in previous comments) that my figures are based on all BEV cars being charged in the evening/night, as a worst case scenario. Obviously, some, such as high mileage users (ironically) will do some daytime charging, then there will be cheap opportunites (when RE generation is high and prices are cheap) to charge during the day, if plugged into a smart charger, and on an appropriate tariff (these tariffs already exist), and also if you have PV (home or work) and are able to charge at those times. But best to work against the highest numbers on here, for now.

Goudy

Going back to my original comment

"The government has had a haphazard approach and basically made a plan to ban petrol and diesel cars then left the market to sort itself out in regards to what we will all have to buy and the infrastructure to run it.

It's going to happen, but they aren't paying for any of it, we all will!"

And

"To be, what's the phrase they like to use, Energy Secure? We will need to rethink the use of batteries at some point."

I still think that is correct.

The government has left enterprise to lead the way and there is a price to pay for that which we will all pay in one way or another. 
They are going to do it as cheaply as possible and charge as much as they can.

Every point made regarding battery EV's and HGV's I understand could and may be correct, particularly for those with the resources.
But we here in the UK and a lot of other places in the world haven't those resources. 

I'm just not talking about Gigafactories, but what these factories will need to to produce these batteries.
A, They are of a finite amount.
B, They aren't exactly under are feet now are they. 80% plus are seemingly controlled by less than friendly governments.

So eventually demand outstrips supply and then availability, but things could be far worse before that, say if a dubious government that produces and supplies the resources start throwing more weight around in places like Taiwan.
All resource bets are off.

Ok hydrogen might not be as efficient but it could be more secure.

If we look at oil, petrol and diesel in the same way, we'd never really consider it a power source today or gas or coal just on efficiency but it worked and was mainly reliably sourced, with the odd exception which again was usually geopolitical.

We will, before long have to reconsider how we store power for use and with all eggs in the one basket, the battery, that will come much sooner than we all think.  

ComicGeek

Martyn1981 said:

ComicGeek said:

Martyn1981 said:

Ectophile said:

While the National Grid are happy that they have enough capacity, it's the local power networks that are going to be the problem.  Particularly that last few hundred yards from your local transformer to your home.

For many years, it's been assumed that a house that isn't heated by electricity will use about 2kW when averaged over a day.  So if you're building an estate of 100 houses, all with gas boilers, then you need 200kW of transformers to supply the estate.

But an electric car on a home charger can draw 7kW for several hours.  And it will be even worse when gas boilers are banned and we start switching to electrically powered heat pumps.

But the DNOs (District Network Operators) are doing what privatised utilities usually do: nothing, until something goes wrong.  Then they patch things up when they break.

I don't think that's correct. The existing set up is capable of providing enough power for power showers (7-10kW), or for electric space heating via resistive heating*. So they can manage high continuous load already. Homes will have 60A - 100A main fuses, which equates to about 14kW to 23kW.

That's based on diversity though, with the DNO rightly assuming that not everyone in your street is running high electrical loads at the same time. I know that our 30 yr old estate is based on an average 4 kVA (3.4 kW) per property for gas heating, whereas modern estates use the 2-3 kVA figure. Each house may have the capacity to run at high load, but the local transformer can't cope if everyone starts doing it - that's why you have to make DNO applications for PV, battery, EV chargers and heat pump installations so that they can monitor the local situations, and why it's not helpful when people avoid making applications.

So nomal baseline usage for a gas heated house is going to be 100-300W - there are then spikes in load when people use appliances. The gamble by the DNOs is that there is sufficient diversity across houses (and the larger the area served the greater diversity is applied) to even out the spikes.

Random time delays are included on all new EV chargers now to prevent them all starting at the same time in peak periods. That is one way that they are trying to control peak load demand. But if everyone in the street owns an EV then they can't allow everyone to start charging at 7kW at 11.30pm each night on a IO tariff - that's when smart charging plays a key part, sharing the available capacity across multiple households and preferably across the full 24hrs. I expect that there will be staggered off peak periods across a local area.

The problem is that it needs full cooperation between DNOs, energy supply companies and home owners - but hardly an industry that's fully trusted by home owners, just look at the issues surrounding the smart meter rollout!

Hi, sorry quick point. You refer to baseload for your comparison, but you really need to compare to the evening peak load, as that better reflects what the local network can manage (4pm to 8pm, with highest demand 5pm to 7pm). The averaged demand for BEV charging will be less than that.

I think that's the main point, but I have a very different conclusion to you. Our estate has gas heating, and was designed in terms of electrical loadings for most to have gas cooking as well. You could argue that improvements in refrigeration, LED lighting, TVs etc can offset a small EV load spread across multiple houses - but if you also factor in moving from gas cooking to electric cooking (which most models that look at heat pump migration fail to consider) in that same evening peak, and then also the heating heat pumps operating in the evenings, there is a problem.

MEM62

My wife has an electric car - a VW ID3.  It's brilliant and works well for her as most of her motoring is local and she has a charger at work.  Indicated range can be as far as 270-ish miles but that goes down to 170 when the weather is below freezing.

It would not work for me as I cannot charge at work and I have a round trip commute of 90 miles per day.       

Martyn1981

The issue of demand outstripping supply for storage is one that gets repeated a lot. The most popular being that there's not enough lithium in the world. This is of course false, it's just that we aren't currently producing enough as demand has risen. The same applies to ICEV's, when they started to be deployed there wasn't even a petrol industry, it was simply a by-product of kerosene production (for lighting), that was often thrown away. Lithium prices this year actually fell and the Chinese Gov stepped in to reduce production to prevent prices falling too far.

But that's just one type of battery storage. As another poster already mentioned, we are now seeing some BEV's coming out with sodium ion batteries, and sodium is not in short supply, anywhere. There are also aluminium batteries being developed. So any scare stories about battery materials are simply that, scare stories.

To think that all storage will be one type - battery, with the 'all eggs in one basket' thinking, is wrong.

As we expand the use of renewable generation, we will also need more storage, possibly 500GWh of intraday storage for the UK, for balancing, but that could be provided by V2G (vehicle to grid) services, making double use of the vehicle fleet. Ignoring large vehicles and fleets, though these are starting to factor in V2G earnings/economics, the UK BEV car fleet would be around 1,500GWh.

For longer duration, and larger scale storage, such as interday, there are loads of storage technologies already being tested, with many already starting to get commercial deployments. These won't need the same materials, and can be provided by flow batts, LAES (liquid air energy storage), CAES* (compressed air energy storage), compressed CO2 battery storage, heat batteries (interseasonal**), and many more.

One that has a lot of potential is actually H2 storage. Whilst H2 is a pig to transport, it works well on a fixed site. So using electrolysers, excess RE (after intraday storage has been filled) can be used to produce H2 for storage, and then the H2 used to power CCGT (combined cycle gas turbines, what we currently use for gas generation), or fuel cells, to produce leccy when needed.

We may need the equivalent of several days energy storage for poor RE periods. We currently average ~1TWh of leccy per day, but in an all leccy future, in the winter (heatpump demand), it will probably be closer to 3TWh. After allowing for other generation, and interconnectors, storage estimates for the UK are around 11-56TWh by 2050. This type of storage H2 (or CAES) is about 50-60% efficient, and estimates of UK potential storage using old gas wells and saline aquifers are in the region of 2,000TWh+. So only a small amount of the potential would ever need to be developed.

So we don't need to worry about the availability of materials for construction, nor relying on unsustainable fuel (oil/gas/coal) from other countries, good or bad.

I'm sorry if this seems like I'm being overly dismissive, but the 'problems' being thrown out are quite old, whilst the solutions/options already being developed/deployed seem to be being ignored, or unknown.


*As an example, a CAES system is being developed in the Netherlands, with 320MW/26,880MWh, so that's 84hrs.

**The UK won't need interseasonal energy storage, as our demand peak is in the colder months, and our RE deployment is heavily weighted towards wind, especially off shore wind, which has a large winter bias. So there is no need to shift summer sun to winter, or winter wind to the summer. However, developments in heat storage, where excess heat is stored in commercial scale insulated containers, or buried underground, is actually rolling out in some colder countries, and appears to be viable for interseasonal heat storage.