RE: Lotus Unveils 'Range Extender'

[xyphod]

Wonder if there are any other microgeneration plants that could be considered.
i.e. some sort of closed loop steam turbine, micro nuclear plant ;o).

The other option (touted around by an ex CEO of mine) was to get garages to charge batteries.
To fill up you drive to your local garage, whack the battery out and stick in a fully charged one!

[The Wookie]

Lol, anything's possible on the power generation front, but generally speaking efficiency, power to weight, size, complexity etc etc all has to be considered.

As for battery changes....

http://aftermarketbusiness.search-autoparts.com/af...

"Through Agassi's global Better Place network, Israel's EV presence is already on the move with the construction of parking meter-like plug-in charging stations and a demonstration-model robotic battery exchange facility; you pull your car in, and a fading battery is automatically swapped for a fresh one in less time than it currently takes to fill up on gasoline. "

Problem with that is that it limits vehicle diversity due to fixed battery sizes limiting both packaging and vehicle size and power variation. It also raises issues with battery condition, and customer acceptance of the odd knackered pack

Edited by The Wookie on Wednesday 9th September 13:39

[xyphod]

Yep Agassi is my ex CEO

[The Wookie]

Really! Must have been an interesting bloke!

It's an interesting idea, not sure it's practical on a large scale though

[xyphod]

He as a true visionary a real loss when he left.

From what I've read and heard the idea is that the infrastructure (i.e. garages) already exists.
They all have three phase mains (good for charging big batterys quickly). And it fits in with how we use cars now.

Completly barking mad idea though. Rather than carry the power around with you (all that weight) how about pumper car style wire mesh above the road and a large rod picking up the leccy ;o)

[The Wookie]

Hmm, electrocution... It would have the added benefit of halving the chav population in the space of mere weeks...

Alternatively you could have inductive loops in the road.... drive over charging strips every now and again like in Wipeout on the old Playstation!

[plasticpig]

xyphod said:

Wonder if there are any other microgeneration plants that could be considered.
i.e. some sort of closed loop steam turbine, micro nuclear plant ;o).

The other option (touted around by an ex CEO of mine) was to get garages to charge batteries.
To fill up you drive to your local garage, whack the battery out and stick in a fully charged one!

Quite a lot of research is being done into nuclear batteries. Batteries using Strontium 90 are still used by the USSR to power lighthouses in the Barents Sea. The great thing about Strontium 90 is that it is a waste product from nuclear fission. I doubt it will ever see the light of day in a car however.

Edited by plasticpig on Wednesday 9th September 13:58

[hahithestevieboy]

ctallchris said:

hahithestevieboy said:

Indeed there are technical problems with current capacitors and you will allways get losses with any machine. However the newer nanotech capacitors and batteries have some serious merit and one or the other could be phased out as technology improves. There is already proper research going on in america (sorry cant remember link) for using capacitance in hybrids like this and there was a mini prototype (by the guys that make in wheel motors for wheelchairs) years back. It's all doable. Dont kid yourself that it's not.

Never said it wouldn't be in the future i just said that current technology was not available yet that would be cheap / safe / maintanable / compettitive.

I would not be suprised if capacitors become more widely used but as current technology stands rapid charging lithium ion batteries can absorb the energy from a rapid stop from high speed as they take up charge nearly as quickly as a capacitor until they are nearly empty - check out altairnano's work with titanium cathodes in lithium ion batteries. Those are available today what will be the best technology in 5 years who can guess as there's probably more investment in battery tech than there is in capacitor tech though this doesn't mean the batteries will drop in price faster or necceserally advance quicker.

Yeah, I'm aware of altair nano's work. It's interesting stuff. And a great performing battery. There are already interesting capacitors using much of the same tech as those, and with similar performance claims. I probably came accross a bit OTT with the caps but hey ho. There is already a car sporting nano batteries. Some californian 4x4 being sold to companies. Very interesting indeed. What is also interesting is that the nano batteries have been sold to lockheed/the us govt and some think that they'll dissapear from sight. Anyway, the tech is there for suitable capacitors (especially for short storage) but at the moment it is relatively unavailable because no one manufactures is en-mass

[MrTrilby]

The Wookie said:

Amazed that your Prius actually hits 50mpg in both motorway and town driving, you must drive it very gently. Worth pointing out that I would expect this Jag to get close to it's peak fuel economy regardless of driving style.

Many vehicles already have A/C powered directly by electric compressors, in fact I believe the Prius does, along with all of the Lexus hybrids. Cabin heating could be more of an issue, but I suspect that a decent control strategy will sort that out.

Edited by The Wookie on Wednesday 9th September 13:09

It doesn't get driven gently at all - it's a company car with a fuel card, so the interest is more in getting home quickly than saving the company some money off the fuel bill. If you run with the A/C and heater off, it'll do better still. And yes, the Prius does have electrical A/C and that's the reason for my curiosity. Running the A/C with the petrol engine off will drain the battery extremely quickly. A/C is very power hungry. And in the winter when you run the heater, the economy takes a dive because the car runs the petrol engine more than it otherwise would, just because you're leaching so much heat out to warm the cabin.

I'm assuming that the ranges quoted for battery only operation on the forthcoming EV and range extended cars are calculated under a similar regime as the present fuel economy testing - with the A/C and heater off, at 20C. So the range extender engine might be seeing more use than people expect.

[The Wookie]

Economy will certainly get worse, but don't forget that on a conventional engine with belt driven A/C that the energy drawn to run it is confined to the efficiency of the engine at whatever load speed points it's being run at, which are likely to be suboptimal. If the engine's being run at peak efficiency to charge the battery, then the chances are that the penalty for the A/C will actually be less than that in a conventional car.

As for heating, you're right, heating a passenger compartment does consume a great deal of energy, in fact one could argue that in the winter a conventional car becomes dramatically more efficient as the waste heat energy is being used. Expect either cabin thermal insulation to improve and/or the generator strategy to change such that it charges more continuously at a lower rate.

As for your economy, then I'd guess that the nature of your average drive well suits the nature of the driveline, and that it's the right vehicle for you! Plenty of people struggle to get economy figures to approach those of a last gen diesel. In the case of the series hybrid it doesn't really matter what your drive is like, it should offer economy benefits across the board.

[hahithestevieboy]

The Wookie said:

ctallchris said:

Nice Post one minor ammendment

The Wookie said:

Wheel Motors

Might be useful some day, but at the moment they have poor rest torque (and thus gradability) due to direct drive, poor low speed efficiency, and very limited braking ability.

PML flightlink (british engineering company)
http://home.deds.nl/~daihard/electroCar/Hi%20Pa%20...

Possibly an exception. They haven't published too many technical specs but these are supposed to have fairly high torque at low speeds

I've actually done quite a bit of work on them, as I said, poor rest torque due to direct drive, limited braking ability. The reason they haven't published too many technical specs is that they haven't got them to work very well yet, particularly with gradients (think pulling away on a car park ramp) and thermal management

ETA - What you have to remember is that a normal engine has torque multiplication for pulling away.

So a light hatchback with a 100Nm engine will probably have a 3.3:1 first gear and a 4:1 final drive

100 x 3.3 x 4.1 = 1300Nm

so two of those electric motors with a total of 1500Nm is barely more than a boggo shopping trolly, but will more than likely have to pull a damn sight more weight. Once you've taken heat performance degradation, you've got a problem.

Edited by The Wookie on Wednesday 9th September 10:53

Never seen the point of wheel motors. I would have thought that it'd be better to mount the motor on the chassis with a reduction gear and then drive the wheel via a short drive shaft. Surely that would answer many of the regen braking and rest torque problems and reduce unsprung mass. It would be nice to see the end of conventional consumable and energy wasteful braking systems.

[The Wookie]

Thing is, once you've put in a reduction gear, you're increasing the cost and complexity and reducing the efficiency to a point where it makes far more sense to stick a properly sized electric motor with a final drive!

I wouldn't be surprised if we start seeing performance EV's with a motor and final drive on each axle, and with conventional brakes being downsized and only taking up the mantle when the batteries are full or the demand is too high.

I don't think conventional brakes can be completely eliminated, not just because of the practical aspects of regen braking but also the well known danger of driveshaft failure on inboard systems

[hahithestevieboy]

The Wookie said:

Thing is, once you've put in a reduction gear, you're increasing the cost and complexity and reducing the efficiency to a point where it makes far more sense to stick a properly sized electric motor with a final drive!

I wouldn't be surprised if we start seeing performance EV's with a motor and final drive on each axle, and with conventional brakes being downsized and only taking up the mantle when the batteries are full or the demand is too high.

I don't think conventional brakes can be completely eliminated, not just because of the practical aspects of regen braking but also the well known danger of driveshaft failure on inboard systems

Thats interesting what you say about drive shaft failure. Didnt know about that. I would have thought that you could over-engineer sufficiently to eliminate that and surely you'd still have the other 3 wheels??

So you reckon that you'd have a motor+diff+gearbox per axel for 4 wheel drive? Yuck!! I would have thought just go the whole hog and give it 4 motors, then it'd be easier to put in things like yaw control trickery for each wheel.

I would be interested to know how much torque you could apply to the wheels through regen. Is there a big problem with that? Can you not force the motor to regenerate energy at the same rate it can give it out? Also where stupendous braking forces are required cant you just reverse the current in the motors or would that just cause them to heat up too much? It would be nice to put all of the energy back into the battery?

Would a cvt transmission on each axel make the system better or would a reduction gear/final drive work better? DO motors have problems operating efficiently at the different speeds required required in a car if you were to say the top speed was 200mph?

[JonnyVTEC]

kambites said:

The Wookie said:

Stuff

So the power figure they're giving is for the generator not the motor? How utterly irrelevant.

Lotus have designed the engine, you can then fit what ever motors in the drivetrain that you want, so that bit isnt related to Lotus. Hence no motor output. Thats more to do with the battery capacity and power output to determing motor sizing.

Is not quoting the number of cup holders an equal concern?

Its worth noting that 3600rpm is the sweet spot for a reason. Plenty of 60Hz AC stuff already exists

Edited by JonnyVTEC on Wednesday 9th September 21:57

[jerrytlr]

The Wookie said:

yet more interesting stuff

Wookie - very impressed with your posts, you clearly know your stuff, many thanks for sharing your knowledge with us in what has turned into a very interesting thread (after a shaky start!).

If you don't mind me asking, what company do you work for?

Cheers,

Jerry

[Talksteer]

endorium]Studies comparing the environmental consequences of hydrogen production and use in fuel-cell vehicles to the refining of petroleum and combustion in conventional automobile engines find a net reduction of ozone and greenhouse gases in favor of hydrogen.[29 said:

Hydrogen production using renewable energy resources would not create such emissions or, in the case of biomass, would create near-zero net emissions assuming new biomass is grown in place of that converted to hydrogen.

That is from wikipedia. I have seen the same info in many places. Plus not only is it better to produce and it does not emit emissions when used in cars, it is a never ending source.

Just to chip in and state the following:

Hydrogen = a crap battery (not an energy source)

To convert energy (and usually high grade energy) into hydrogen and then compress and package the hydrogen into size that will fit in a vehicle requires far more energy then charging a battery which is usually a very efficient process. "Cheap" hydrogen is available only by extracting hydrogen from fossil fuels which saves precisely zero carbons.

Renewable energy does not have the capability to generate even the amount of energy that the country demands has at the moment never mind if you were to power all of the nations transport with something as inefficient as the "hydrogen economy".

Hydrogen is potty and it ain't ever happening.

Biofuels may have some role to play but only where the energy density requirements are such that you can't use electricity (generated from nuclear energy, or renewable s where appropriate) such as shipping and aircraft. Demand for oil as a whole is far to great for biofuels to come close as it currently stands.

[Black S2K]

This has been one of the most enlightening and interesting threads I've read on here.

Thanks esp. to The Wookie.

There are a couple of issues wrt plug-ins, mostly related to losses within the National Grid and its overloading, which I believe are ignored when calculating overall efficiency. I wonder if Lotus' engine ought to be considered as part of the home generation system, which Honda was advocating.

Intrinsically, because power stations/grids are so inefficient, Honda proposess a small natural gas genset in every garage, to recharge your car. or light your home. The cooling circuit also heats your water.

Speaking of gensets, whatever became of Turbo Genset? IIRC, it was a UK company which proposed its tiny, affordable gas turbines for the purposes described.

Edited by Black S2K on Sunday 13th September 15:26

[Talksteer]

Black S2K said:

This has been one of the most enlightening and interesting threads I've read on here.

Thanks esp. to The Wookie.

There are a couple of issues wrt plug-ins, mostly related to losses within the National Grid and its overloading, which I believe are ignored when calculating overall efficiency. I wonder if Lotus' engine ought to be considered as part of the home generation system, which Honda was advocating.

Intrinsically, because power stations/grids are so inefficient, Honda proposes a small natural gas genset in every garage, to recharge your car. or light your home. The cooling circuit also heats your water.

Power stations and the national grid are efficient. Most of the arguments in favour of micro generation hinge around using the "waste" heat to heat buildings. This in theory boosts the thermal efficency higher than the power station at the end of grid.

However to produce the waste heat at a usable temperature you actually reduce the electrical power output of your plant, electricity is a high grade energy source (you can do almost anything with it) the low grade heat can be used for space heating and that is all.

The main issue however is that micro generation ties your energy network to natural gas, the least secure and the first run out. From an efficency and security of supply point of view you are better of with large nuclear units, a national grid and space heating with ground source heat pumps. Have a look at:

http://www.withouthotair.com/

Black S2K said:

Speaking of gensets, whatever became of Turbo Genset? IIRC, it was a UK company which proposed its tiny, affordable gas turbines for the purposes described.

Gas turbines: High performance, long life, low cost - pick any two