|Engine Doctor||27/07/2019 10:36:09|
2271 forum posts
Well said Pete. I dont mind new developments but a few enthusiastic electric car users wont save the planets and the old ic technology will only be sold to other countries to continue poluting .
|Doc Marten||27/07/2019 11:13:14|
|365 forum posts|
Guys, this is an interesting topic but these questions and debates are being regurgitated over and over again, please read what's been said in the previous pages before you decide to post, l'm sure I'm not alone in being disappointed when I see a new reply only to find it just repeats what has been said many times before. We don't know how the infrastructure will be improved to cope with demand, we don't know how the lost revenue will be recuperated, we don't know if charging technology will ever match the flow rate of a petrol pump, we don't know in which way the environmental affects will swing, etc,etc,etc. It's all speculation.
Can we continue this thread with the progress that EV's are making as it happens and just accept that the governing forces have decided to saddle us with EV's and the support needed for it to be a viable replacement as the future? I'm not happy about that but nothing being repeated on here is going to change it. Can we see the announcements and actual work being committed to the plan being posted here to keep us informed of the progress rather than bicker with eachother over guesses? It's spoiling the thread.
11322 forum posts
Trevor, I cannot see that the present position with respect to the minimal charge (financial) being allowed to continue with respect to EVs.
When I rather nebulously make reference to extra cost, I am generally making reference to all the facilities that will be required to get and keep electric vehicles powered. That is generating capacity, distribution capacity nationally, local charging capacity etc.
Everything has to be paid for,
What tends to distort the issue is that IC vehicles are in general more efficient than electric vehicles when all the losses are considered. We have touched on the issue much earlier. Taking heat engine type generation approx. 30% efficient, the the losses compound as the electrons get to the point of use. Wind power also is not straight forward, hence all the derelict grinding and pump wind mills around Europe, not quite as efficient as at first sight. If it were not for the Carbon taxes and Wind Turbine grants and feed in tariffs, the true cost of electric power would be much clearer today, The recent issues with the Steel Industry demonstrates that there are costs associated with playing fields that are distorted. Where some get Carbon Credits others do not and so on.
All inefficiencies leads to higher costs to some one, often seen in our standard of living. We may become acutely aware when we compare our personal position, with others, particularly abroad.
11322 forum posts
We should all be aware of the big issues in forming judgment as to the balanced argument.
I do agree with respect once the rules are set it is up to all to adapt and take advantage of them. Although we need always to keep a cautious eye to the bigger picture, as that will often determine a lot of the future rule changes. Which is often a balance of politics, self interest and sometimes logic.
With respect to vehicle developments. The most obvious is the lack of range. The very obvious solution is to increase the total battery capacity by a factor of two. The obvious down size is cost, weight, and space. The wight issue results in more energy usage as good old Newton told us that F=ma, then his first law comes into play needing better brakes and so on. The Space issue just means we all would need a SUV type bodied vehicle.
Again on these basic issues all the manufacturers are considering. Then the boring issues to most, it comes down to electric control systems. Motors, which are best discussed at the bar, after a pint or two, the motors in my car are the best being Zeilithium Hysteresis loop augmented etc. Differential units, a complete turn of, unless two motor drive with limited differential movement, operating in conjunction with a 20Gbyte processor to enhance cornering and low friction conditions. That is before all the quirky ideas are investigated.
It could be a good 5-10 years until the optimum set up emerges. Until then the Lohner-Porshe and the equivalent of the Wooler Beam Engine, will be tried and disappear in search of a viable product.
IMO all far to early to be certain, all the big boys will be playing the ball with a straight bat. Hence all the surreptitious test vehicles that we barely notice.
|Tom Sharp 2||27/07/2019 18:36:57|
3463 forum posts
The answer is, self contained city areas, where people have no need to venture anywhere outside the city limits.
|Frank Skilbeck||27/07/2019 20:04:12|
4430 forum posts
Can you back that up, the best fossil fueled power plants, gas fired combined cycle plants, have a thermal efficiency of over 60%, and an electric car is over 85% efficient, so that's an overall efficiency of 50% or so. And the engine thermal efficiency you quote is an engine running at optimum conditions, say cruising at 55 mph maybe, plus that doesn't include the losses in extraction, transportation, refining and then distribution of liquid hydrocarbon fuels.
|2641 forum posts|
Forget motors, compare the volume of a single gallon of diesel (gallon fuel can dimensions) that can take my Mondeo....easily 50 miles. How far would your typical EV get on a battery of similar size / volume. Scale it up to your heart's content, the figures are still against batteries. I've gone 500 miles when working in Scotland (reminds me of the Proclaimers song) between fill-ups of the Mondeo's large tank, batteries don't come close. The energy density of batteries still needs work as does the time taken to fill them.
|Nigel R||27/07/2019 22:22:19|
2985 forum posts
You've missed the grid transmission efficiency and battery charging efficiency.
I've read that the oil we use in our cars, as much is used again to get it there. I'm unsure how accurate that is though.
|Frank Skilbeck||27/07/2019 22:33:59|
4430 forum posts
Yep a 60 litres of diesel has around 640 kwh or energy compared to the 60 kwh battery in a new Nissan Leaf+ that is only good for upto 240 miles.
|Frank Skilbeck||27/07/2019 22:54:05|
4430 forum posts
Yes, but I didn't take account of the losses in the supply of petrol/diesel either.
An interesting concept is EORI which the a measure of the energy ratio to extract fuels, which is going down as oil extraction is become more difficult as the easy to access reserves have been exploited, renewables are becoming competitive on this basis, **LINK**
Edited By Frank Skilbeck on 27/07/2019 22:54:52
11322 forum posts
We will go round in circles trading potential efficiencies. Electric power is no miracle with respect to efficiencies as a system. I am sure you will recognise that refineries can make claims to incredibly high affiances if all the associated plants are combined. Which potentially leads into a discussion of most combined Heat and Power plants more often than not are special cases, not the norm.
Wether we like it or not electric power generation and transmission incurs significant losses.
Perhaps a good comparison is comparing the cost of boiling a kettle of water using Gas and electricity, Using gas is significantly cheaper. Of course some want to tax gas more, but taxing does not change the basic system efficiency, just distorts our perceptions.
I think we all recognise that some things are better than others for certain things, gas lighting is not generally ideal, whereas electric lighting ticks all the boxes.
More likely than not, electric cars will become the norm, generally because pollution from IC vehicles is seen as a major issue, Yet the real underlying problem is to many people already on the planet, in ever larger and polluted cities. This leading to campaigns to stop eating meat, having no dairy herds, Yet when all the animals have been eliminated, one day, plant based diets will also be exhausted.
I also note that high speed trains are an issue, as the Mega watts of power necessary to power one, puts into perspective the power usage of all the combined road going vehicles, however powered..
|Trevor Crook||28/07/2019 07:51:38|
|838 forum posts|
Frank, your response to C8's Mondeo figures points out that an ev will go about half as far on 60kWh as a diesel will on 640kWh, which emphasises the tremendous effeciency of evs. I'm sure a great many people haven't looked at those figures. The cars are getting better and cheaper all the time, the infastructure and supply effeciency are a different matter.
|Frank Skilbeck||28/07/2019 08:30:08|
4430 forum posts
Ereflog, boiling a kettle is a poor analogy as the thermal efficiency of this is typically 80% plus, now when you convert that energy to mechanical efficiency then that is not very efficient because you can't recover most of the energy, which is just expelled as heat.
Also combined cycle gas power generation is a gas turbime running at circa 30% efficinency and using the exhaust gas to generate steam to run steam turbines, to being up the overall efficiency. This is now most of the fossil fuel power generation in the UK.
11322 forum posts
The kettle is a very good example of real world economics. It is considerably cheaper to use gas than electricity to boil a kettle.
Perhaps the other thing that needs to be done, is to consider that you should not pick and choose which bits of a system you choose for efficiency comparisons. Combined heat and power are parts of a system. Gas, steam turbines have specific efficiencies at best, as a component in a system.. The Rankin Cycle will indicate the best that can be achieved, although real world results will never equal or match the cycles. Of the closed systems I believe that the Stirling cycle would be the best, except for the regenerator never come close. It is the same with Wind Turbines, they have at best an efficiency. Steam turbines are about 30% efficient, that excludes the alternator, which is just another part of the system
Yet in the real world it is not the individual components that matter, it is the system as a whole. There are fixes that can is specific cases improve some aspects under particular set ups. Just as oil refineries do.
Only today there are suggestions that wind turbines could drive up the cost of electricity by a factor of two when compared to todays cost.
Do not get me wrong, I am not against electricity, I am against blinkered and selective approach as to the real situation, both from system. life time costs and the bottom line of what it costs society, industry and the environment.
There is something wrong with Trevors maths, as there is a factor of 10 difference in efficiencies between Diesel and electric cars. Not even the most selective use of efficiencies bares that out.
Edited By Erfolg on 28/07/2019 11:11:29
|Bob Cotsford||28/07/2019 11:10:37|
7930 forum posts
One aspect to be born in mind that much of the power used in charging EVs will effectively be a by-product of domestic power production as much charging will be done overnight which. as I undestand it, is currently a low demand period. It also means power distribution requirements come down too.
Regardless of efficiency comparisons, the very real fact is that EVs shift most of the airborne polution out of the cities where it harms a great many people so it's worth moving away from IC forthat fact alone.
|2641 forum posts|
It's all very well talking about EV efficiency, but the fact remains that a reasonably sized family car that is electric only, ceases to be a very good family vehicle because of its inferior range compared to an IC car.
I'm not trying to rubbish the technology, far from it; in fact a small Fiesta sized EV with a range of a hundred miles or so might well find a place on my driveway in the coming years for general running about town and other fairly local trips as a second vehicle.
I don't see how I could manage without a decent sized IC car or possibly a hybrid, that will give me several hundred miles range, non stop at the drop of a hat and can tow a caravan for a couple of hundred miles, again non stop and can transport the models and paraphernalia that gets swallowed by my Mondeo Estate at present.
|Keith Miles 2||28/07/2019 13:21:41|
|170 forum posts|
EVs, by definition, can only increase electricity demand, especially if their availability and price eventually equals that of current vehicles and eventually replaces them.
Batteries have to be manufactured and raw materials sourced and processed. Batteries, therefore, will have an increasing environmental impact and the resources are not limitless nor, necessarily, easily accessible.
Even if we can reduce or eliminate CO2 and particulates I doubt that our ability to produce electricity is limitless and I doubt that ever increasing demand, even existing demand, can be met with solar, wind, wave or hydro power. That leaves nuclear energy as the most realistic option with its own potentially extremely serious environmental risks as already seen with Three Mile Island, Chernobyl and Fukushima.
The harsh reality is that ever increasing population and aspiration as well as current expectation can only eventually outstrip our planet’s ability to cope and therein lies the real dilemma.
|Shaun Walsh||28/07/2019 13:22:43|
|175 forum posts|
Just had a look at the Gridwatch website.
Currently there is approximately a 20 gigawatt difference between daytime and night time electricity demand.
Lets assume that people charge their cars overnight using a 3 KW slow charger over 12 hours.
This means that if 6.66 million cars are charged overnight it brings the night time demand up to peak daytime levels.
There are currently 31.5 million cars registered in the UK so it would only take 21% of all cars (assuming we all eventually change to electric) to be plugged in overnight to bring the night time consumption up to day time levels.
If all cars in the UK were now electric and by some fluke were all plugged in to charge overnight (I know, very unlikely) instantaneous demand would be 94.5 GW, current grid capacity is approximately 85 GW
Gas generation as I type this is running at almost 40% of total electricity generated, wind is 13.5% and solar 13.4% the rest is provided by nuclear and interconnections with other countries' grids. At night, solar will be off-line and the slack will need to be taken up by more CCGT generation. I think this highlights that we will need to invest in more baseline capacity to ensure that the lights don't go out if electric vehicles achieve high market penetration or we will have to pay companies to shut down at night to lessen the load.
Edited By Shaun Walsh on 28/07/2019 13:23:42
Edited By Shaun Walsh on 28/07/2019 13:24:22
Edited By Shaun Walsh on 28/07/2019 13:24:57
|Paul Marsh||28/07/2019 16:16:51|
3669 forum posts
Just saw one of the cooling towers being demolished at Ferrybridge power station.
So, this facility closed down, and lost another power station, yet plans to put 31 million cars on the National Grid by 2040.
Yeah, right... Missing something here, oh, yeah, electricity when it goes dark. One plus One isn't five!
Had a look, we've lost or about to lose 12GW in the last 3 years! (Radcliffe-on-Soar is due to close by 2021ish
Edited By Paul Marsh on 28/07/2019 16:18:39
Edited By Paul Marsh on 28/07/2019 16:22:20
|Frank Skilbeck||28/07/2019 17:01:51|
4430 forum posts
Agreed, using gas for heating is quite efficient, but using gas or liquid fossil fuel to provide mechanical energy isn't and thats what I was referring too.
As regards power generation a combine cycle gas turbine which uses the exhaust gas to produce steam to drive a steam turbine give an overall thermal efficiency of over 60%.
Trevors maths were not 10:1 but 5:1, but one of the advantages of electric cars is that they recover kenetic energy when they slow down and don't use fuel when they are stopped in traffic, plus an IC engine is only at it's best efficiency when it's running at a specific point, so real world efficiency is much less.
I'm not trying to be selective I understand the limitations of electric cars and drive a diesel myself, but have to admit that in terms of overall pollution per mile driven then an electric car produces less pollution. Note the average CO2 emissions per kwh in 2018 were 270 g/kwh ( last 24 hrs 212 g/kwh), a Nissan Leaf will do 200-240 miles, say 320 km on 60kwh, so that equates to 51g/km. Not great and the UK has one of the lowest power generation CO2 emissions of all developed countries (down from over 500g/kwh a few years ago), mainly due to the switch from coal to combined cycle gas.
Edited By Frank Skilbeck on 28/07/2019 17:09:29
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