Hybrid Vehicles

The 'correct' hybrid has a diesel engine sized to move the vehicle down the road at highway speed, fully loaded and with a few ponies to spare, and sufficient battery capacity to handle normal acceleration and regenerative braking needs. And, obviously, sufficient electric motorage to give the desired driveability characteristics. It should be what is known as a 'parallel' hybrid, not a 'series' hybrid. That is, have a conventional drivetrain with a single electric motor/generator helper. (A series hybrid uses the engine to drive a separate generator, and electric motors are the full-time drive for the car. Like the big diesel-electric locomotives except that they do not have batteries.) In an electrical failure situation a parallel car would still be driveable, in limp-home mode, the mechanical part of the drivetrain being conventional would thus benefit from the maturity of that industry, likely being more reliable than the electric part.

The 'correct' hybrid is not a Remote Emissions Vehicle (REV, a.k.a. electric car), nor a big diesel with a little electric motor. Nor a gasser of any sort. These all have less total system efficiency. (A series hybrid would be a suitable architecture for a REV with an on-board charger for long trips. More expensive, and less efficient system-wise for the general motoring public than what I describe. OTOH, the fuel type for such an on-board charger is nearly irrelevant, since for efficiency it would run at optimum RPM and loading where all fuel-type engines are nearly equal in efficiency, so you could use gasoline for those.)

It has been said that with diesel hybrids that you never get payback on the gasser-to-diesel cost increase. That may be true over the warrantee period, in temperate climes, with current refinery and fuel distribution practices, but considering the potential lifespan of such a vehicle and colder climates I tend to disagree. It is ludicrous to spend scarce and expensive battery power on a heater, so as you're going to use a fuel engine's waste heat for cabin comfort anyway the diesel will idle much more efficiently, and for far longer and with less poisonous emissions than a gasser will. Diesel engines also tend to be more durable, at least if they're correctly designed. I know that I've certainly had far less trouble with them than the gassers in my experience. Also, if refineries were making significantly more diesel, let's say 50% of the national fleet needs, diesel would again be cheaper than gasoline and there would in fact be a reasonable direct payback period. (Refineries now can choose what to make the crude into, and they're currently choosing to make mostly gasoline. Of the diesel they do make, they're selling a very large percentage of it to Europe where they can make more money on it, artificially driving up diesel cost here. In effect, we're subsidizing the European fuel tax structure.)

The batteries are the most evil part of a hybrid, you want to minimize them. Average drive power should be from fuel, all peak needs should be met electrically. HVAC should be completely traditional, driven off the diesel. The diesel engine can be stopped at lights, if the battery charge is sufficient and you have an auxiliary coolant circulation pump ala MB to heat the cabin from residual engine heat during stops. The engine should start if the cabin starts to cool. (A Webasto-style fueled auxiliary heater would be even better, but is a bit on the expensive side. Will forgo. You must use diesel waste heat when available rather than additional fuel, anyway. I think, initially at least, that having no auxiliary heater should be the way to go.)

I'm thinking a 20 HP diesel with maybe 100 HP of electric motor. The diesel needn't have a turbo, but if it's more efficient on the highway with one then it should have it. The battery pack should be relatively small, and could take you at most a few miles on its own. The diesel could be a little oversized for mountain pass power, etc.; one of the beauties of a diesel is that they're more efficient than gassers when run at partial loads so you could have a more driveable car without a general fuel penalty, with diesel. Diesels have more low-RPM torque, and so a small diesel engine is generally more driveable than a small gas engine. Such a vehicle would have an indefinite range on the road, you could go anywhere, as far as you wanted and at any time, without inconvenience. Refueling would take mere minutes. Just like today's vehicles.

What I'm talking about is entirely buildable, today, with current technology. And it shouldn't be very much more expensive than a dangerously underpowered econobox, yet would be much more driveable and efficient.

That, in AWD sedan or wagon form and with a stick shift, or rather, a transmission that gives me shifting control when I want it such as for downgrades, or to avoid an upshift when there's an impending stop, I might purchase. Provided it had a traditional fail-safe key switch and no stupid shrubbery on the dash. And got an honest 60 MPG or better. (Since you can purchase traditional diesel-only vehicles that get 50 MPG you'd better be able to beat that solidly with your hybrid or else what's the point?) Oh, and was styled to look like a car rather than a tennis shoe or an electric shaver. No high ass or haunches, no high and rising beltline, no 'gun bunker' look, no plastic excrescences. No smug 'green' styling. No drive-by-wire mother-may-I stop. No auto-park let-me-just-grab-the-steering-from-you-when-I-want-to. Etc. I want it simple, reliable, and safe. Largely based on well-proven technology. And attractive.

I don't want much, do I? I think I will not hold my breath while I wait.

Electric Vehicles

In spite of my definite bias against electric vehicles for the general motoring public I think there is a place for them, too.

There are some factors stacked against them:

  1. Batteries. Ones large enough to power a car are expensive. The industrial resources required to make them is also something you cannot ignore. Pollution costs of making (and disposing of) them also must be considered. They are a consumable, like tires.

  2. Pollution. These are Remote Emissions Vehicles, REV's, the pollution from burning fuel is still there, it's just not right where you will notice it. Sadly, a substantial amount of fossil fuel is still burned to get the power in the first place, nationally. (Here in Washington most of our power is hydroelectric, with wind and nuclear supplements. A REV, here, is actually a pretty good thing so far as pollution and global warming go.)

  3. Distribution. The national electrical distribution grid is surprisingly lossy, a lot of that remotely-burned fuel is in fact going to waste. There is also some concern that the national grid as it now exists is not capable of supporting a significant percentage of the national fleet being REV's.

  4. Charging time. It can take hours at best. No long road trips in your expensive new electric car!

  5. Charging losses. There are significant energy losses involved in the process of charging any electrochemical battery, this is also wasted energy.

  6. Self-discharge. Most newer battery technologies (post-lead/acid) discharge at a significant rate whether you're using it or not. An electric car must be driven frequently (or rather, charged frequently whether driven or not) or else it may self-discharge its battery to a damaging level. This is also wasted energy. 'Toy' cars (Tesla?) are particularly vulnerable. A commuter car would be much safer in this regard.

  7. Range. It starts out terrible, and it gets worse. People forget that batteries degrade both with age and with use. What might have been a barely-acceptable range when new might no longer be achievable within a year or two. To be really practical, and not vaguely dangerous to rely upon, the vehicle needs an on-board fuel-based charger to extend its range. More cost, weight, etc.

  8. Road tax. If the national fleet starts being composed of a significant percentage of REV's expect Uncle Sam (and his horde of greedy relatives) to notice that the (currently fuel-based) road tax revenues are dwindling, and to do something about it; your 'nearly free' electricity will not continue to be so. Ideally they come up with a way to not just put road tax on the juice that runs your refrigerator, heats your house, etc. Yeah, sure.

For urbanites with a moderate daily commute, who have the resources to plug in at home overnight for a recharge (and also perhaps at work), they may make sense. Because of the inherent limitations of such a vehicle they probably cannot be a family's only vehicle.

With all of these factors I don't think that the national fleet being composed of a significant percentage of REV's would be good for us at all. (See Crock: Electric Cars.) Still, here are my criteria for a good REV:

  1. Econobox. A small commuter-type car. The vehicle is inherently limited-purpose, it needs to be relatively inexpensive and particularly efficient, both of which are aided by small size.

  2. Large-ish battery to give you enough range for REV-only driving, at least a good portion of the time. High-speed/current charger for fairly rapid recharges at home installations or at other special charging stations, but also capable of charging (albeit much slower) via a regular wall outlet out at Uncle Fred's farm.

  3. Onboard fuel-based charger to extend the range, but fairly small. Would not be sufficient for indefinite road trips on the highway, which requires substantially more sustained power, but might be able to provide an indefinite range around town, especially in stop-and-go situations where it would get some chances to 'catch up'. Because this engine is only for charging the battery it can be optimized for efficiency of purpose, which means that it could be nearly anything: gasoline or diesel reciprocating engine, gas turbine, etc. Inexpensive and reliable would be good, I'm thinking that a small gas turbine would fit the bill nicely. Excellent pollution characteristics and efficiency at a single load point, its poor throttle and partial load characteristics are irrelevant in a battery charger, and it's simple and small. (No liquid cooling system required, and its lubrication oil supply doesn't get contaminated with combustion byproducts, and so lasts a very long time.) I'm thinking of something in the 5HP range or so, maybe about the size of a couple of stacked paint cans. A high-RPM turbine could mate directly to a high-RPM alternator, eliminating the need for transmissions, etc. Bonus points for being able to burn nearly anything: gasoline, diesel, kerosene, alcohol, any mix thereof, just pour whatever's available into the tank... (That is probably not practical, but it sure would be nice!)

  4. HVAC, sadly, would have to be a special-purpose battery-powered system, which in extreme climes would really rob you of range. While you might try to make use of the waste heat from the charger it's not something that you can rely upon since it wouldn't always be running. Probably pointless to try to use it directly given that you still have to have a battery-powered heater anyway. It should be possible to use a heat-pump configuration of the AC for mild heating needs, that might save some energy. (Utilize waste heat from the exhaust stream of the charger or the electric motor's cooling vents to feed the heat pump's evaporator when in heating mode? Maybe worth a look! Probably a three heat-exchanger system would be best, with valving to select which non-cabin heat-exchanger is currently being used: hot-stream or cool-stream, depending on the heating/cooling mode. Pump probably driven by an efficient brushless variable-speed motor that runs continuously at the speed that best meets the system's needs, rather than cycling at full speed as most systems do today. Even possible, I suppose, to utilize the charger's exhaust stream in an air-air heat exchanger in the cabin air intake stream, when heat is desired. This has a couple of problems: one, passenger safety, that heat exchanger would have to be extremely reliable and durable, and two, you'd need to be able to switch the exhaust stream away from there when more cabin heat was not wanted. Still, with such co-generation in operation the system could be very efficient, extracting cabin heat from the exhaust stream both in the air-air exchanger up front, and in an air-refrigerant hot-stream exchanger downstream from there.)

  5. Heating probably supplemented by seat and steering wheel heaters. These 'luxury features', delivering heat directly to point of use as they do, consume less energy than full-on cabin heat. Could probably make up for a relatively anemic heat-pump cabin system.

  6. Power steering and brakes would also need to have special systems, although if this truly is an econobox it is entirely possible that you could do without the power steering. A small electric vacuum pump could easily keep a traditional vacuum brake booster charged for use, so that shouldn't be much of an issue. (Especially with regenerative braking helping out.)

I don't think I'd want one of these, but I can see that many might. In fact I personally could use one of these, the usage pattern of my usual winter beater (the Frankenheap) matches the REV very well. I just doubt I'd want to pay for it, when I already have a cheap beater with a heater.

The other way this might go would be something like the Tesla, which is certainly not an econobox. A high-end car like this, though, ought to be able to bear the startup costs of making a small, efficient gas turbine for on-board charging. Once pioneered somewhere like this, it could trickle down to the rest of the EV fleet in time.

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