Energy, Global Warming, and Electric Bicycles (Energy Flow Analysis)

[daniel.weck]

"Energy Flow Analysis with an Emphasis on Personal Transportation"

I hope this is not a double-posting, as it is not a very recent article. Anyhow, lots of interesting facts here:

Energy, Global Warming, and Electric Bicycles - ein Knol-Artikel von J.L. Radtke

Regards, Dan

 

[jasono]

That's a fascinating article, thanks. I noticed on the One Show they were doing something with an electric car, but kept missing the point. Yes there would still be a traffic and pollution problem if everyone switched from petrol to electric, but it would be a reduced environmental problem, simply because an electric motor is more efficient than the internal combustion engine

Also, surely it's a no-brainer. What good is a sporty petrol burner in a World that is struggling to sustain life?

 

[HarryB]

simply because an electric motor is more efficient than the internal combustion engine

...that would depend on where the energy came from in the first place. Even if we all went for electric transport there wouldn't be the infrastructure to support it anyway.

 

[Barry Heaven]

...that would depend on where the energy came from in the first place. Even if we all went for electric transport there wouldn't be the infrastructure to support it anyway.

A very good infrastructure is of course already in place. Unlike electricity, there is no other transport fuel currently available which is piped directly into your home. For pedelecs that is really all you need. For larger scale EVs your home electricity supply is more than adequate even if EVs took off over night (which of course they will not). Most charging is done overnight when there is spare capacity for electricity generation, so EV charging brings a net efficiency to the supply system. Another advantage is that, in combination with smart grids, it will be possible for the grid to use EV batteries as a backup supply source to help balance peaks and troughs in supply generation; a constant problem for generation. This is also an ideal solution for balancing the varying output from most renewables such as wind and solar.

 

[john]

Another advantage is that, in combination with smart grids, it will be possible for the grid to use EV batteries as a backup supply source to help balance peaks and troughs in supply generation; a constant problem for generation. This is also an ideal solution for balancing the varying output from most renewables such as wind and solar.

I have read this so many times but never seen anyone mention the potential problems. Firstly peak demand is in the early evening, just when cars with exhausted batteries are being plugged in so may well be a net drain on the grid. Secondly, even if the battery was full, how many users would want them drained in the early evening such that their later evening range would be reduced. Thirdly, cycling any battery reduces its life.

Of course, given enough financial incentive, anything is possible.

 

[flecc]

it would be a reduced environmental problem, simply because an electric motor is more efficient than the internal combustion engine

Also, surely it's a no-brainer.

In independent vehicles, ic engine with fuel tank or electric motor with battery, the electric vehicle is far less efficient than the ic one.

Far from a no-brainer.
.

 

[Barry Heaven]

I have read this so many times but never seen anyone mention the potential problems. Firstly peak demand is in the early evening, just when cars with exhausted batteries are being plugged in so may well be a net drain on the grid. Secondly, even if the battery was full, how many users would want them drained in the early evening such that their later evening range would be reduced. Thirdly, cycling any battery reduces its life.

Of course, given enough financial incentive, anything is possible.

That's why a smart grid is needed to make allowances for these factors. One of the features of such a grid is that electricity is costed according to demand, hence the cheap period would be when demand slackens in the later evening.

Cycling batteries does reduce their life but a lot of money and effort is being put into battery development. For example the battery for the GM Volt is being built to give a minimum lifetime of 10 years.

 

[Barry Heaven]

In independent vehicles, ic engine with fuel tank or electric motor with battery, the electric vehicle is far less efficient than the ic one.

Far from a no-brainer.
.

I don't think the data supports this at all. An ic engine has hundreds of moving parts generating friction, losing energy by heat and also lost via heat from the exhaust. The best you can hope for is 30 - 40% efficiency. Electric motor efficiency with essentially one moving part is far higher.

Regardless of any debate about efficiency the simple fact is that oil is running out and alternatives are the ONLY way forward. Hydrogen is often touted as the answer but that can only be made by reforming gas, coal or oil at immense inefficiencies or using carbon free sources. In all of these it is much more efficient to store energy directly in batteries rather then creating hydrogen, distributing it and then liberating the energy by burning or via fuel cells.

 

[Straylight]

At the time of the industrial revolution, there was initially no infrastructure to support it, and so vast sums of capital were invested in digging canals, building steam engines etc. I contend that currently what is lacking is not the technology so much as the will to employ it. The general view at the moment is that everything currently works and is relatively affordable, so why bother, when changes will naturally involve a premium to be paid by the consumer, for no individual short term benefit.

This lack of transigence is what is stalling any meaninful discussion, and more importantly decision making on behalf of the politicians, as if any of them were brave enough to take the steps nescessary, they wouldn't stand a chance of being re-elected.

It's a sad, sorry state of affairs, particularly when you think that at the time when the effects of climate change are seriously felt, that same electorate will be screaming at the politicians, demanding to know why nothing was done to mitigate it.

For this reason, I believe that progressive energy policy needs to start at home, with people examining their own lifestyles and making minute savings where at all possible, and maybe investing in forms of micro genneration, expensive though they are. It only takes a significant minority to get the ball rolling, and lead the way to such things being regarded as 'normal'.

Though we're far from perfect, in our house we spend less than £1/day on electricity, and do not have a gas supply. This is achived through the use of a combination of wood and solid fuel to heat the house, water, and for cooking. Most of this is done with one appliance - an ancient Rayburn stove with a back boiler. When I have the money, I will be erecting a wind turbine, to further reduce our reliance on the national grid.

There's an interesting documentary, currently on iplayer here if anyone's interested, btw.

 

[flecc]

I don't think the data supports this at all. An ic engine has hundreds of moving parts generating friction, losing energy by heat and also lost via heat from the exhaust. The best you can hope for is 30 - 40% efficiency. Electric motor efficiency with essentially one moving part is far higher.

That just repeats the previous error of excluding the fuel source. As I said in my post, ic with fuel tank or electric with battery, the electric becomes much less efficient.

Put another way, the electric vehicle powered by battery is much less efficient than the ic one powered by fossil fuel, and that's why ic overtook electric in the earliest days of the motor vehicle and has stayed way ahead ever since for independent travel.

When the electric motor is powered from an external source like a conductor rail or line, the position is completely reversed of course.
.

 

[jasono]

In independent vehicles, ic engine with fuel tank or electric motor with battery, the electric vehicle is far less efficient than the ic one.

Far from a no-brainer.
.

Hi, I have read that the electric motors are 90% efficient as opposed to 30% for the internal combustion engine - hence the no-brainer comment!

 

[Barry Heaven]

That just repeats the previous error of excluding the fuel source. As I said in my post, ic with fuel tank or electric with battery, the electric becomes much less efficient.

Put another way, the electric vehicle powered by battery is much less efficient than the ic one powered by fossil fuel, and that's why ic overtook electric in the earliest days of the motor vehicle and has stayed way ahead ever since for independent travel.

When the electric motor is powered from an external source like a conductor rail or line, the position is completely reversed of course.
.

Yes Flecc, I agree that taking into account the whole life-cycle of power generation, transmission, storage and use of the stored power, then overall this results in an efficiency of 20% to 25%, slightly better than the average 20% efficiency of ic vehicles in urban driving. However these figures ignore the source of energy. If it comes from renewables then the overall efficiency of energy conversion to electricity is far better as it does not deplete fossil fuel resources.

As a small scale example I charge my electric bike from my solar panel which, whatever way you look at it is, highly efficient in terms of resource use and no CO2 emissions.

There is no realistic way of powering a car from an external source although concepts such as induction loops buried in road have been put forward. So, given that oil is running out, bio fuels have their own problems with competing with food crops and hydrogen is very inefficient, then battery EVs are the best bet for the future.

 

[emissions-free]

That just repeats the previous error of excluding the fuel source. As I said in my post, ic with fuel tank or electric with battery, the electric becomes much less efficient.

Put another way, the electric vehicle powered by battery is much less efficient than the ic one powered by fossil fuel, and that's why ic overtook electric in the earliest days of the motor vehicle and has stayed way ahead ever since for independent travel.

When the electric motor is powered from an external source like a conductor rail or line, the position is completely reversed of course.
.

Flecc,

I would have thought that the electric vehicle only becomes less efficient than an IC vehicle at some point where the batteries become a significant weight disadvantage. However even a very small engined scooter still requires a relatively heavy engine and transmission which would have to be considered in the total weight as a fair comparison. An ebike would have a big weight advantage even compared to the lightest of scooters.

The way I see it, the electric vehicle will be more efficient at short journeys and the IC vehicle will then match the efficiency once a specific range is required. Beyond this the IC vehicle would then steadily improve it's relative efficiency compared to the electric vehicle.

If that's the case, then it's just a matter of keeping the range within acceptable limits. If battery technology improves with regards to the energy density the distance at which they become less efficient than an IC would be greater. If fast charging and the infrastructure was in place to do this as we would put fuel into a car, then the required range becomes less of an issue.

Just my thoughts anyway

 

[flecc]

In a joint answer, yes, if various conditions are put on to favour electric such as small light vehicle, short range etc, it has some viability.

But for all round independent vehicle use for passengers, goods etc, only ic does the job, and you only have to go outside to see the proof!

I'm not arguing against electric, far from it, just asking for realism since the changeover is very, very far from a no-brainer. We will have to massively change a vast number of facets of how we live our lives, and the future electric world will be almost unrecognisable from today's one.

The infrastructure to suit a world of independent electric transport for all will be so immense that I think the idea will be abandoned in favour of improved mass transport systems, more efficient and controllable. The days of the many driving to out of town shopping centres will probably end in favour of online shopping with the goods brought to us, few vehicles serving many, rather than many vehicles for the same purpose.

I don't think there's any point in continuing with old thinking about us all travelling in our own vehicles and repeating the ic engine mistake all over again, bringing with it all the attendant evils like road deaths and injuries, congestion and vehicle associated crime, to mention but a few.
.

 

[emissions-free]

For sure once you get out of the city or have to cover long distances, a car is definitely superior, but for short distances and busy cities, I'd say a small electric vehicle is very viable and in some cases far superior. I get across town faster on my bike than I could on the subway even though I have to take a short ferry on that trip. I also doubt that a car would be able to beat me at bust times even though they have the advantage of tunnels and high speed roads.

I've started to see some e scooters over here in china with a kind of canopy to protect against the worst of the weather. They seem to be a standard part that just bolts onto a typical scooter, with clear perspex front/rear with a roof and open sides. Nobody bats an eyelid at them over here but I could imagine you'd get a few funny looks in the UK... If people were a bit more open minded about things, I'm sure there's ways to make more viable forms of transport where you don't have to suffer excessively but can still have a cost effective and viable electric transport solution.

Mass transport is great in big cities but not pleasant IMO. Give me an e bike any day

Here's a couple of beauties I found Imagine the look on a teenagers face if dad turned up on 1 of these to pick them up from school.....

Scooter canopy-Large Photo & Picture

Scooter's Canopy-Large Photo & Picture

 

[flecc]

No argument as I've said, some uses are or will be viable, like e-scooters. I agree about better protected scooters and I think the BMW C1 concept is superb and could become an electric in the Vectrix manner. Unfortunately our government stands alone in insisting that helmets must be worn with it, even though it's unnecessary with that design and nowhere else requires that. Of course that immediately limits the widespread appeal it could have, either ic or electric. C1 photo below:

 

[daniel.weck]

Unfortunately our government stands alone in insisting that helmets must be worn with it, even though it's unnecessary with that design and nowhere else requires that.

I did not know that ! What a nonsense ...

 

[flecc]

I did not know that ! What a nonsense ...

Yes it is. There's no technical objection to the design, they just can't be bothered to bring in the necessary legal amendment and point blank refuse to discuss the matter, just insisting helmets must be worn.
.

 

[Barry Heaven]

In a joint answer, yes, if various conditions are put on to favour electric such as small light vehicle, short range etc, it has some viability.

But for all round independent vehicle use for passengers, goods etc, only ic does the job, and you only have to go outside to see the proof!

I'm not arguing against electric, far from it, just asking for realism since the changeover is very, very far from a no-brainer. We will have to massively change a vast number of facets of how we live our lives, and the future electric world will be almost unrecognisable from today's one.

The infrastructure to suit a world of independent electric transport for all will be so immense that I think the idea will be abandoned in favour of improved mass transport systems, more efficient and controllable. The days of the many driving to out of town shopping centres will probably end in favour of online shopping with the goods brought to us, few vehicles serving many, rather than many vehicles for the same purpose.

I don't think there's any point in continuing with old thinking about us all travelling in our own vehicles and repeating the ic engine mistake all over again, bringing with it all the attendant evils like road deaths and injuries, congestion and vehicle associated crime, to mention but a few.
.

I agree with this, however most people will not. You only have to see what happens when a government has the temerity to suggest that car use should be curbed by measures such as congestion charging, taxing car parking etc. Even where the revenue raised will go to support public transport there is little interest. We have been raised to believe in cars as almost a birthright and public transport as a shoddy, second class symbol of communism. This is why Jeremy Clarkson is so popular.

Having said that, the transition to EVs is starting to happen, aided by plug-in electric hybrids. You don't see much evidence looking outside but most of the major manufacturers have models lined up ready to go in the next few years.

 

[Barry Heaven]

Vectrix is reborn: Vectrix lives again, has lithium future — Autoblog Green