Will the transition from fossil fuels be similar to that from Petrol to Diesel?

[indalo]

Will the transition from fossil fuels be similar to that from Petrol to Diesel

The question posed by the original poster assumes that there has been a transition from petrol to diesel and I'm not sure that assertion is accurate. It's true that diesel-powered vehicles abound in far greater numbers today in the UK than previously but there are many reasons for that, some of which are so diminished in importance that they are no longer valid. By way of example, I cite these two facts:

1) Diesel is now more expensive than petrol and

2) The advent of solid-state electronics has negated the tendency of the petrol engine to misbehave.

When it is considered that the latest, small petrol engines are hugely powerful, very frugal, quieter than their diesel equivalents and selling in increasing numbers, it's not at all clear that the diesel revolution in the UK was anything more than a passing phase. I say that because there is some evidence to suggest that the latest, small petrol engines from the VW group and the ones on offer in the Fiat group cars represent the optimal power plants for the cars that most people drive this side of the atlantic.

Mainland europeans were into diesel long before we began to consider it as suitable for private cars so we were late to the party. We will probably be caught lagging again in the movement back to petrol which is gaining momentum across mainland europe, the natural home market for most VW and Fiat group motors. Regardless of any major shift in the petrol/diesel balance, there is one glaring omission from the contributions in this thread and that is hydrogen.

Safe storage of volatile gases has always been a problem and the notion of a hydrogen-powered car has been bedeviled by that problem but we are much, much closer now to producing viable hydrogen-powered vehicles in large number than ever before. In time, I expect a hydrogen car will be where the Prius is today.

Given the idea that biofuels might be the solution has been completely debunked, to answer the original question, no; the transition will represent a sea-change in people's thinking about how we convey ourselves around the planet and how we conserve resources for future generations. The switch from petrol to diesel and the possible switch back again will pale into insignificance when compared to the abandonment of fossil fuels.

Perhaps we should all consider horses and mules again as the power source for our personal transport. Moreover, perhaps we cyclists should all be reverting to unpowered bikes of about 12Kgs and getting off and pushing when the going gets too tough?

Regards,
Indalo

 

[Oiseaux]

...................

Perhaps we should all consider horses and mules again as the power source for our personal transport. Moreover, perhaps we cyclists should all be reverting to unpowered bikes of about 12Kgs and getting off and pushing when the going gets too tough?

Regards,
Indalo

Funnily enough, whist pushing the pedals with motor off on yet another trial of a hub motor electric bike yesterday, that very thought came to mind.

 

[banbury frank]

Hi

In the USA in most States Diesel cares are Illegal

Frank

 

[trex]

alexk-il
Let's take the 50% efficiency of the gas generators and pretend that there are no oil/coal burning power plants. Let's assume the electrical motor in a car always runs at optimal load (no stops at traffic lights, no heavy traffic) and ALWAYS has the efficiency of 78%. Multiplying 50% by 78% gets you 0.5 * 0.78 = 39%.

Alex, on average, you only get 20% in diesel out of crude oil, the rest goes to petrol, jet fuel etc. On the other side, generators can burn crude oil. The route to mechanical energy is more efficient via electric motors in principle, even when you take the relative scarcity of copper into account.
In the news: Deripaska will sell billions of kw of Siberian hydroelectric to China. That's a better way than burning coal.

 

[Oiseaux]

I would be interested to know the viewpoint of the hundreds of families whose homes have been burnt to the ground with little or no compensation to enable this 'planet saving' project to go ahead !!

 

[Oiseaux]

Hi

In the USA in most States Diesel cares are Illegal

Frank

At this moment in the 'good ole US of A' all state sponsored 'caring !!' is soon to become illegal.

 

[flecc]

Perhaps we should all consider horses and mules again as the power source for our personal transport. Moreover, perhaps we cyclists should all be reverting to unpowered bikes of about 12Kgs and getting off and pushing when the going gets too tough?

Or perhaps we should, and one day will, stop travelling all the time as we do at present. There can be few things which expose the idiocy of modern human behaviour more than the view of a city from above, constant streams of vehicles, mostly cars, in perpetual motion all rushing in opposite directions.

The seeds of change are there and have been for over a century. The telegraph brought a dimension of another human to us rather than us travel to them. The telephone improved on that, and then radio brought groups of others to us in one dimension, with television then expanding the dimensions of communication. Now the internet brings others and their services to us without us travelling, and now even allows us to go to work without travelling, even enjoying conferences together from anywhere on the planet.

Since our modern food is produced by a tiny proportion of the population and our goods can be manufactured by ever smaller numbers via technology, the need for people to travel has been constantly reducing. Much of the travelling we do could be made unnecessary by changing the structures of the way we work and where and how we live.

A world in which our current total of human travel is halved is easily within reach, and I see no reason why our current travelling couldn't be eventually reduced to a fraction of it's present level.

Then we could stop worrying about what fuel we use for that remaining transport and movement of goods, it just wouldn't be a problem any more.

 

[trex]

how about world population growth? transport will remain a challenge for the foreseable future and questions need to be asked about which fuel we'll use for this because it influences how we vote and where we should invest.

 

[flecc]

That's all "old thinking" though Trex, it's what we need to change.

Who says the population must grow?

If we aren't using the fuel as I suggest, the questions of how and where we invest don't arise.

We are in a thinking rut that's leading to multiple disasters, global warming, loss of our most valuable lands, widespread starvation, severe water shortages.

To change that direction we first need to change our thinking. Instead of saying how will we travel, ask why do we need to travel? Instead of how can we grow enough food, ask why do we need so much food? Those sort of questions open up fresh ways of avoiding the problems, rather than having to find ways of dealing with their ill effects.

 

[lemmy]

My quote from Nils Bohr was about trex's post - just a joke, hence the smilie. Being the old geezer I am now, any certainty about the future tends to make me chuckle. I have lived long enough that I remember predictions from experts from 50 years ago, from flying cars to a new ice age.

Flecc, I agree wholeheartedly that our future does not lie in compounding technology upon technology but in changing our outlook. I do not think that will happen though, because we first need to convince a couple of billion people in Asia that they cannot aspire to what we already have.

 

[flecc]

Flecc, I agree wholeheartedly that our future does not lie in compounding technology upon technology but in changing our outlook. I do not think that will happen though, because we first need to convince a couple of billion people in Asia that they cannot aspire to what we already have.

That certainly looks the case, but it might not be as hopeless as it superficially seems. China's one child policy has prevented them reaching 2 billions, reducing from approaching that and holding at about 1.3 billions, and despite labour shortages their government isn't relaxing the policy.

If I were to put a couple in a prison and giving them a choice, have one child only or I slowly starve you and your offspring to death, we know what they would choose. But the fact is that we are all in a prison, the prison of this planet and eventually facing that choice. The larger the population grows, the more we all come to realise that harsh truth, and at some stage we are likely to respond appropriately and take the choice that hypothetical couple accepted.

 

[trex]

are we still in thinking rut like flecc said? Flecc and lemmy, aren't you two a tad pessimistic about the prospect of 2 billions Chinese and Indians wanting to have what we are having? My contention is that they are going to get it soon and their net contribution is positive. There will be solar capture then hydrogen fusion becoming industrial process (a possibility if the rate of progress in laser power continues for another 50 year), a lot of people cannot and want not think of what is possible beyond 50 year time frame.

 

[alexk-il]

Alex, on average, you only get 20% in diesel out of crude oil, the rest goes to petrol, jet fuel etc.

Hi Trex,

Are you trying to imply, that in case of diesel fuels 80% of energy is lost as opposite to the crude oil fired generators? Well, the petrol and jet fuel are still used in internal combustion/engines so the energy is not lost. And the rest is used for plastics/food industry which makes burning crude oil for energy even more inefficient.

On the other side, generators can burn crude oil

But they usually don't in US or Europe. Year 2004 power plants statistics for UK:
gas – 39.93% (0.05% in 1990)
coal – 33.08% (67.22% in 1990)
nuclear – 19.26% (18.97% in 1990)
renewables – 3.55% (0% in 1990)
hydroelectric – 1.10% (2.55% in 1990)
imports – 1.96% (3.85% in 1990)
oil – 1.12% (6.82% in 1990)

Whatever the efficiency of burning oil in power plants, it is so insignificant, that it can't be seriously considered for the comparison.

The route to mechanical energy is more efficient via electric motors in principle, even when you take the relative scarcity of copper into account

True, if you compare pure electrical vs diesel/petrol motors performance. Not true, if you check the numbers for the whole energy flow cycle from fossil to your engine/power plant. And no, you can't burn all oil in generators, we still need jet fuels, plastics and food components.

Replacing the fossil fuels with nuclear ones is still not really much better since the energy still released into the ecosystem adding its part to the global warming.

The only true way to enjoy the efficiency of electrical motors, is to use the renewable energy sources, such as bio-fuels, hydro, wind plants, etc. And frankly, I don't really care where I burn the bio-fuel - in my car or in the power plant, as long as it is not fossil based.

 

[trex]

Alex, if you transform chemical energy (as in hydrocarbons) into mechanical energy (for use in transport) by the internal combustion route, you will incur higher (thermally) cost. The maximum yield for thermal to mechanical is by the Carnot theoreme: 1-T(cold ambient)/T(hot steam). This yield can be higher at the power station than in an average i c engine. The oil refining process also adds to thermal loss for the i c engine. The proof is in industry: they have diesel generators but they use electric motors to do the work. I agree with you that we should use bio-fuel or renewables, I still wish for quicker adoption of electric cars - we have to have many cheap e-cars to make the switch.

 

[lemmy]

a lot of people cannot and want not think of what is possible beyond 50 year time frame.

No-one can think what is possible in 50 years time with any meaning at all. Go back 50 years and see the prediction for the future then. When I look at all the scientific arguments here it makes me think of the discussion of how many angels can dance on the head of a pin? Interesting to debate but essentially shouting down a well.

No matter what we do, the earth cannot sustain the way of life of a rich European or north American for everyone living on it even now, let alone the future. China may have limited each family to one child but that has not stopped its population increasing. India has no limitations and a democratic government has no way of imposing such a thing if it wishes to get elected.

We have gone along way to destroying our environment already and our rate of destruction is increasing, not decreasing. Even a relatively aware country like our own is outputting more co2 this year than it did last. We are currently talking wishfully of electric vehicles with batteries weighing a ton and a life of 5 years. We have 25 or more million cars. That would be 25 million tons of toxic landfill per annum on top of what we do not have space for now. That is the future?

I love the idea of the future and its technology but hope and belief achieve nothing in themselves. Even with transport as responsible and dull as electric bicycles there are many people clamouring to go faster - translated - burn more energy. We would have to change our most deep rooted habits to secure our future but I cannot see us doing it until confronted with imminent disaster.

Personally, I have most of the latest technology, digital cameras, iPads et al because I love it, I have a car and 2 bicycles and may buy a nice big motorcycle.

My reasoning is that if I am on the Titanic, why go second class

 

[alexk-il]

Alex, if you transform chemical energy (as in hydrocarbons) into mechanical energy (for use in transport) by the internal combustion route, you will incur higher (thermally) cost. The maximum yield for thermal to mechanical is by the Carnot theoreme: 1-T(cold ambient)/T(hot steam). This yield can be higher at the power station than in an average i c engine. The oil refining process also adds to thermal loss for the i c engine. The proof is in industry: they have diesel generators but they use electric motors to do the work. I agree with you that we should use bio-fuel or renewables, I still wish for quicker adoption of electric cars - we have to have many cheap e-cars to make the switch.

Trex,

Nice theory, however it is totally irrelevant:
1. Most of the fossil burning power plants today are Coal/Gaz generators. Replacing engines in cars is not going to make more efficient use of energy from that point of view. However electric cars is a nice step towards the world with no more oil left

2. I'm glad you mentioned the Carnot theorem. It is good to refresh my knowledge of thermodynamics. Anyway, the T(Hot stream) is the flame temperature of burning fuel. Surprisingly, in high-pressure Diesel engines, the adiabatic flame temperature may be higher than in less-pressurized generators, so I am afraid this inevitably means that diesel generators are at least equally efficient (if not more) than simple oil burners. Sorry, your formula doesn't support your claim.

3. Diesel + Electric motor is a hybrid solution, which is, as I mentioned in one of my previous posts, more reasonable than a pure electric car mostly due to power regeneration. As for vessels, submarines, and locomotives, the main drive behind the diesel-electric transmission is simplicity of the mechanical transmission, low maintenance and eliminating the need of geared transmissions. However, "Hydraulic transmissions are claimed to be somewhat more efficient than diesel-electric technology", so the direct diesel transmission technology is not that hopeless.

Alex

 

[trex]

Alex,
I just googled a wiki on ic engine which quotes:
Most steel engines have a thermodynamic limit of 37%. Even when aided with turbochargers and stock efficiency aids, most engines retain an average efficiency of about 18%-20%.[11][12] Rocket engine efficiencies are better still, up to 70%, because they combust at very high temperatures and pressures and are able to have very high expansion ratios.
Although I accept that the adiabatic cycle inside the combustion chamber is more efficient than steam cycle, the ic engine has to have 4 strokes of which 3 are non producing.

 

[Mussels]

Alex,
I just googled a wiki on ic engine which quotes:
Most steel engines have a thermodynamic limit of 37%. Even when aided with turbochargers and stock efficiency aids, most engines retain an average efficiency of about 18%-20%.[11][12] Rocket engine efficiencies are better still, up to 70%, because they combust at very high temperatures and pressures and are able to have very high expansion ratios.
Although I accept that the adiabatic cycle inside the combustion chamber is more efficient than steam cycle, the ic engine has to have 4 strokes of which 3 are non producing.

The IC engine only needs two strokes, four is used as it's more efficient.

 

[lemmy]

The IC engine only needs two strokes, four is used as it's more efficient.

More fuel efficient, not more power efficient. No four stroke engine of a given capacity can produce the power of the same capacity two stroke.

I had a 350 RD Yam in 70s followed by a 400/4 Honda. No comparison, the 2 stroke Yamaha did 32mpg and went like s**t off a shovel. The Honda did 55mpg but was distinctly stately in demeanour.

Even in writing this I think about flogging my Kalkhoff and getting an old Yamaha RD with the money and s*d the environment

 

[Mussels]

Even in writing this I think about flogging my Kalkhoff and getting an old Yamaha RD with the money and s*d the environment

Don't do it, it will never live up to the memories.