Are Electric Vehicles that Green?

[Jeremy Harris]

23 minutes ago, SteamyTea said:

Perceived is a better description.

 

 

Or not perceived, as one significant issue with a hydrogen fire is that it cannot be seen - the "flame" is completely invisible.  I remember this being demonstrated many years ago during some lab safety training, pretty scary having an invisible, high temperature "flame". 

[SteamyTea]

It is really about risk, the risk of the initial accident, then the risk of s fuel leak. Then the risk of a fire. Then finally the risk of bring burnt.

Probably lower than a liquid fuel car.

Ethanol burns with a clear flame. I was at Pocono speedway and wondered why they were cooling the driver with buckets of water.

An odd sight.

[Markblox]

4 hours ago, SteamyTea said:

Perceived is a better description.

Didn't the UK's only Hydrogen filling station (at the time) explode this year? I'm sure I read about it and I think it led to nToyota withdrawing their model from the market for a while.

[Jeremy Harris]

Just had a look at Zap Map and it's showing that there are currently 14 hydrogen filling stations across the UK:

 

 

 

Just for comparison, this is a map showing just the rapid (50 kW or more DC) charge points across the UK (albeit filtered to only those that will fit my car - so this doesn't include all the Chademo chargers):

 

[SteamyTea]

1 hour ago, Markblox said:

Didn't the UK's only Hydrogen filling station (at the time) explode this year

Had a look, only found one in Norway.

 

51 minutes ago, Jeremy Harris said:

14 hydrogen filling stations across the UK

One of which is in Redruth, which seems an odd place to put one.

Though it has been described as the new Shoreditch (Redruth, not a gas pump).

[Markblox]

13 hours ago, SteamyTea said:

Had a look, only found one in Norway.

 

I could swear I read about an explosion in the UK, never mind, will just have to increase the medication!

Happy new year.

 

[Markblox]

14 hours ago, Jeremy Harris said:

Just had a look at Zap Map and it's showing that there are currently 14 hydrogen filling stations across the UK:

 

 

 

Just for comparison, this is a map showing just the rapid (50 kW or more DC) charge points across the UK (albeit filtered to only those that will fit my car - so this doesn't include all the Chademo chargers):

 

 

I think this explains it neatly, It is pointless even considering what system of energising electric cars is best because this is a Betamax/VHS situation and that means for cars at least, BEV's win. 

[SteamyTea]

6 minutes ago, Markblox said:

Betamax/VHS situation

Except, for the foreseeable future, BEVs are best because of the better efficiency.

Noticed that last year, over 50% of our electrical energy came from renewable and nuclear sources.

https://news.sky.com/story/more-power-came-from-renewable-energy-than-fossil-fuels-in-uk-in-2019-11898806

Just got to increase that by 60 TWh/year to cover personal transport.

[Jeremy Harris]

34 minutes ago, SteamyTea said:

Just got to increase that by 60 TWh/year to cover personal transport.

 

Does that allow for the efficiency difference between fossil fuelled vehicles and BEVs?

 

Allowing for charge and discharge losses, BEVs are around 80% efficient, whereas fossil fuelled vehicles struggle to get above about 25% efficient in practice.  Peak engine efficiency is around 34% for an Atkinson cycle petrol engine and maybe 40% for a common rail diesel, but very few ICE vehicles run anywhere near peak efficiency.  BEV efficiency is pretty constant, and tends to be better at lower speeds, the region where ICE vehicles are often least efficient.

[SteamyTea]

1 minute ago, Jeremy Harris said:

Does that allow for the efficiency difference between fossil fuelled vehicles and BEVs

I work on 0.25 kWh/mile.

 

[MikeSharp01]

26 minutes ago, SteamyTea said:

I work on 0.25 kWh/mile.

 

1 hour ago, SteamyTea said:

Just got to increase that by 60 TWh/year to cover personal transport.

Save me Googling it and doing the maths - you will probably have it in your head, by how much, multiples of current production, will we need to increase generation capacity by to move all our people transport needs to BEVs then?

[Ed Davies]

Simple calculation says 60 TWh/year is 6.9 GW or 105 W/person.

 

It's not so simple to work out increased generation capacity needed as it's hard to say how well BEV charging would fill in low points in demand. Optimistically, it could be as little as 0 extra generation capacity needed with good use of smart meters, etc. Whatever, in the grand scheme of getting rid of fossil fuels it's a relatively minor blip.

[SteamyTea]

41 minutes ago, MikeSharp01 said:

Save me Googling it and doing the maths

I did the maths (roughly and quickly as I am on way out).

Seeing we have about 22.3 GW installed capacity (wind only) and that produces around 60 TWh/year.

So doubling the wind capacity should just about do it.

That is quite achievable in the next decade, the last decade we have installed, on average 13.7 GW.

 

But as @Ed Daviessays, with a bit of management, it could be less.

We could currently charge about 3.5 million BEVs without any change, 7.5 million by shifting to night charging.

That is for the whole grid supply, not just the renewable element.

 

[MikeSharp01]

2 minutes ago, Ed Davies said:

Optimistically, it could be as little as 0 extra generation capacity needed with good use of smart meters, etc.

Not sure I would trust a smart meter as far as I could throw it - but the low points must, commercially, be in the E7 periods so at night when the sun does not shine so we loose PV as a possible then and - once everybody is using the E7 period do you think our commercial thinking managers will allow us to to keep it - suddenly it won't be a low point anymore!

[SteamyTea]

3 minutes ago, MikeSharp01 said:

once everybody is using the E7 period do you think our commercial thinking managers will allow us to to keep it - suddenly it won't be a low point anymore!

That is why I picked Wind as the RE source.

A lot of the E7 period is linked in with nuclear.

Now there is a problem.  We have to get those locals in Cumbria to keep the waste.  Everyone knows it is going there long term, they are just holding out for more money.

 

[Jeremy Harris]

I charge pretty much exclusively during the night, with the car set to start charging at midnight, whether I'm paying for the charge or not.  A typical charge will be between 30 kWh and 60 kWh, usually at a rate of around 7.5 kW, so the car's pretty much always charging when the grid has a lot of spare generation capacity.

 

Most BEV owners seem to do much the same, but that's mainly because most early adopters have off street parking, and access to home charge points.  There are a lot of people who don't have off street parking, and would be unable to take advantage of off-peak home charging, and that may well be one of the biggest problems to overcome.

[MikeSharp01]

4 minutes ago, SteamyTea said:

keep the waste

Or find  way to burn / denature it - the promise of fusion - MAYBE.

Edited January 1, 2020 by MikeSharp01

[Ed Davies]

10 minutes ago, MikeSharp01 said:

Not sure I would trust a smart meter as far as I could throw it - but the low points must, commercially, be in the E7 periods so at night when the sun does not shine so we loose PV as a possible then and - once everybody is using the E7 period do you think our commercial thinking managers will allow us to to keep it - suddenly it won't be a low point anymore!

 

E7 was created on the assumption of fixed generation capacity and simplistic variation in demand: nothing more sophisticated than time clocks. That's history so E7 is doomed. What we need to do is vary demand to match available generation as far as possible. It's reasonable to have doubts about the current implementation of smart meters but something of the sort is necessary.

 

[SteamyTea]

1 hour ago, Ed Davies said:

It's reasonable to have doubts about the current implementation of smart meters but something of the sort is necessary.

Or buffeting at the local level.

This morning I looked at last year's usage (a bit higher than I hoped).

But what did striked me is that I use, on average, 1.5 kWh/day, on day rate, with a standard deviation of 0.8 kWh and a maximum of 7.5 kWh/day (no idea what I did that day).

So if I was to install 3 kWh of storage, with a 5 kW power delivery, that charged whenever it is cheap, I could probably manage quite nicely.

Then just a case of replacing resistance heating with an HP if some sort.

May have to run some numbers to see what is cheapest overall.

I suspect that a heat pump would give me the best return as 85% of my usage is DHW and space heating.

Edited January 1, 2020 by SteamyTea

[Ed Davies]

20 minutes ago, SteamyTea said:

Or buffeting at the local level.

 

How does that help if you don't know when to buffer? What would your motive to buffer be if electricity isn't cheaper when there's more to spare?

 

The simple notion that electricity is cheaper overnight won't work if a substantial portion of the supply is coming from variable sources. Last night electricity might have been a lot more expensive than tonight, partly because of increased new year consumption but also because tonight is forecast to be windier than last night (at least at this end of the island, maybe different at the south end).

[ProDave]

Just now, Ed Davies said:

 

How does that help if you don't know when to buffer? What would your motive to buffer be if electricity isn't cheaper when there's more to spare?

 

The simple notion that electricity is cheaper overnight won't work if a substantial portion of the supply is coming from variable sources. Last night electricity might have been a lot more expensive than tonight, partly because of increased new year consumption but also because tonight is forecast to be windier than last night (at least at this end of the island, maybe different at the south end).

To buffer or not to buffer can only work when you have real time pricing.  i.e. your smart meter has to communicate to you what the price is right now, in a way that can be read by devices, so they can choose to charge or discharge your batteries, shut off heating loads or turn them on etc.

 

I don't see anything like that built into the present smart meters,  They are just a way to charge at different rates in arrears with no automatic way to tell loads when is the best (cheapest) time to run.

 

This is one of the reasons why I won't have a smart meter just yet, I don't see the present offerings as the solution.

[SteamyTea]

1 minute ago, Ed Davies said:

 

How does that help if you don't know when to buffer

At the moment. Supply is matched to demand with a statistical model. It is why frequency is not the perfect indicator to over or under demand.

I would suspect that in the future, similar models are used to control the grid.

So you can charge a store at known times of over capacity, rather that trying to balance 60 million meters to a few million generators.

 

[Jeremy Harris]

As far as EVs are concerned I can foresee there being a "smart conflict" (it's already happening with Tesla Model 3s, big time).  OLEV require that all domestic charge points that are installed with an OLEV grant (which is the vast majority) have to be "smart", so that the DNO/supplier can control EV charging , as required to balance the grid.

 

"Smart" charge points are not connected to "smart" metering, as the two are run independently of each other, with no clear intention at the moment to ever get them to talk to each other (not sure it's even practical to do this given the way that DCC has been set up).

 

Ignoring the fact that some cars refuse to work with "smart" charge points (all Tesla Model 3 owners, for example, have to find a way to disable "smart" functionality in order to get their cars to charge), there is a fundamental problem in that users will need their cars to be "fuelled" to a certain level for travel the following day, yet the DNO/supplier neither knows nor cares about this (and vehicles cannot communicate their needs to "smart" charge points - there is no communication link in the spec to allow this). 

 

For example, I like to keep my car topped up to 90% charge every night.  The reason being that we have ageing relatives and we never know whether we may be called on to do a long trip in a hurry.  If the DNO/supplier decided that they weren't going to let my car charge, for whatever reason, then that could cause a great deal of pain and grief.  Likewise, if the DNO/supplier decided that they would only let my car charge when the electricity tariff was high, I'd not be a happy bunny.

 

In an ideal world we'd have a unified system that allowed the grid to be balanced by load management, and for consumers to have all their requirements met, at the best possible value.  Call me cynical but I just cannot see that happening, somehow.

[Ed Davies]

59 minutes ago, SteamyTea said:

So you can charge a store at known times of over capacity,

 

Known to whom? How is it known?

[MikeSharp01]

33 minutes ago, Jeremy Harris said:

If the DNO/supplier decided that they weren't going to let my car charge, for whatever reason, then that could cause a great deal of pain and grief.  Likewise, if the DNO/supplier decided that they would only let my car charge when the electricity tariff was high, I'd not be a happy bunny.

You don't have to be cynical to get that this is exactly what will happen because the profit motive will drive it - something like this...

"Which charge option would Sir / Madam like, we have the always full model where you pay a small monthly premium on your standing charge and a charge anytime rate, for your connection so that we allow you to charge your car anytime and we never use it for load balancing OR you can have the hope it will be all right where we can stop your car charging if the grid is overloaded you pay slightly less for the electricity you do get but we cannot be sure you will get it all the time" as we, he says under his breath, can charge people on rate the always full tariff more for it." 

 

The alternative, where the power of the consumer really comes into play, so when he grid is suffering the DNO gets into a bargaining position with you about how much they will pay you to flatten your battery - imagine the trading algorithms,  won't be allowed so you can forget that. Better off building yourself a power station and doing your own thing - suddenly off grid becomes more attractive if you can generate it and store it.