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I think he's talking about these:
https://www.capstoneturbine.co...

well you're looking too narrowly. Electrical generation plants that burn fossil fuels are a lot more efficient than ICE. The use of ICE is based on the ease of accelleration/torque on demand, lack of long startup phases. If you use an electric motor for the kinetic activities, the the options for generating electricity for the powertrain to use are wide open. Say when the battery gets down to 25% charge, you start up a compact gas turbine, and run it until it's back up to >90% and then shut it off. so the duty cycle is long, no varying torque, something like this: http://www.bladonjets.com/ has only one moving part... should last forever, far simpler than an ICE, and likely more efficient. another product: http://www.capstoneturbine.com... Walmart's gas turbine hybrid truck: http://www.greencarcongress.co...

Hmm. Very interesting.

So one of the toughest problems of gas generator design is the thermal limits of turbine material. Making hotter, more efficient combustion is easy. The problem is the turbine melts.

If your working gas and fuel is cryogenic then you're starting out at a temperature much further away from the material limit. The greater difference in temperature has to translate to greater efficiency, as it does in all heat engines.

Mechanically there should be no problems; we're already running air bearing turbine generators in garbage trucks today. A friction-less gas generator + power turbine + electric generator train should operate at cryogenic temperatures just fine.

Diesels in that size are much more efficient, more tolerant of abuse, more tolerant of contaminated fuels, and a lot cheaper to maintain.

Citation? In the video it mentions that a diesel replacement for the power of the turbine would be 2000 pounds, not 200. Not exactly the same size. He also specifies that the turbine requires less maintenance. The turbine(which shouldn't be running all day) is rated at 40k hours(4.5 years continual operation), doesn't use oil lubrication or have a cooling system to worry about. Service parts are filters - fuel and air.

Looking up diesel garbage truck information - I found a study where they had a service interval of 225 hours, probably about every 3-4 weeks. The study mentions going with special motor oil containing stuff that enabled them to 'extend oil change intervals by six times'. So I think that figuring on an oil change between 1-3 months is reasonable. That adds up.

As for contaminated fuels, is that such a big problem here in the USA? Besides, turbines are inherently multi-fuel, so as long as the fuel burns you should be good. If it doesn't even a diesel will hydro-lock and kill itself.

I think that the trick is that you might be thinking of aviation turbines, not power generation turbines. Looking up the Capstone turbine company, they produce power turbines, not aviation turbines.

The important bits I've heard about turbines is a bit that goes like "Small size, wide power band, efficiency, pick two". Aviation turbines aren't as efficient as they could be because they need to operate over a wide power band. However, the turbine isn't hooked to the wheels in this application - it can happily be either off or running in it's ideal power band charging the battery. At which point 1800 pounds saved DOES save fuel because a lighter vehicle can go further on a given amount of energy.

(You can make amazingly efficient turbine engines if you don't care about weight. Forget the terrible helicopter engines, think industrial power generation: multiple heat exchangers, possibly multiple expansion stages, cool, low-pressure exhaust with no waste. Scaled down to 50 HP I expect it would fit nicely in a car. And if it lets you save 80% of the battery weight it can be a good trade.)

Actually, helicopter engines wouldn't be "terrible" in a serial hybrid configuration. They're about as efficient as can be designed without adding a recuperator if they're run at a fixed speed and optimal load. The reason that helicopter engines are inefficient when shoehorned into ground vehicles is usually due to either running at variable speeds or needing to idle for long periods. Neither of those are an issue for a range extender.

Although, a helicopter propulsion engine is probably way too much power for the job (unless you want a serial hybrid with >800 HP). What would probably work best is to redesign a small business jet or helicopter APU (auxiliary power unit) to incorporate a recuperator to improve efficiency and reduce exhaust gas temperature. There are already several models in the proper size class and they could easily be packaged at a weight on the order of one passenger + some luggage.

After some searching, it looks like this company is already producing something along those lines: Capstone

Centralization puts similar objects where a small group of techs can have immediate hands-on access, store spare parts and spare machines, have backup power with economies of scale (large diesel or Capstone turbine gensets), and directly guard and monitor equipment.

That's simple physical, observable reality not requiring citation.

Isolated units which are small involve sacrificing advantages of immediate service. If no workee, dispatching a tech by car or truck with tools and parts is required. If it gets severely damaged by (for example) lightning strike, fire, vandalism or theft that means delivering and connecting a replacement.

"HOLY FUCK I BET THEY NEVER CONSIDERED THAT THEY COULD ALSO PAINT THE CABINET WHITE!"

If so, they would have done that and used an appropriate constrasting Aologo.

See these for commercial examples "light color" use:

http://www.capstoneturbine.com/

Citation needed for the assertion re: Google being environmentally irresponsible because their processes are not simple and easily observed.

Also, post with your nick, bitch. ACs eat shit. :-)

The reason turbines aren't used for automotive use is more to do with the power delivery characteristics than their peak performance. Cars tend to spend the vast majority of their time running at far less than peak power, and turbines are most efficient when run at a constant speed and load. Also, turbines require higher-grade alloys to handle their higher temperatures and RPMs. Traditionally, this means that turbine powered cars have had poor throttle response and been very expensive.

However, the current trend towards series hybrid electric cars allows turbine power plants to start playing to their strengths. If used as a range extender, a turbine generator will be running consistently at optimum power and speed and can be sized for average, rather than peak, power output. For example check out the Capstone CMT-380.

Large NG turbine power plants are around 42% efficient. Turbines are more efficient under a constant load that they are designed for. There are small turbines for individual buildings that use waste heat for heating or absorption cooling. Their electrical efficiency is in the 35% range but using the waste heat can make the overall efficiency 70-80%. (Plus it's nice to have local power generation if the grid goes down.) http://capstoneturbine.com/

Turbine engines are great, and they can be made small. But not cheap. Turbine makers have tried over and over to build low-cost jet engines for light aircraft. After all, large aircraft have been exclusively turbine powered for half a century. But it seems that once you get down to the size for a light bizjet (5-6 passengers), the engines don't get significantly cheaper. The MiniJets web site has information about all known small jet aircraft engines. It's a story of great demo aircraft, with decades of frustration trying to get the cost down. Efforts continue to build a very light jet at a low cost.

The other big use for small gas turbines has been for small scale electric power production.

Then there's the idle problem. The Chrysler turbine car had a mechanical transmission, and the engine continued to consume fuel at a substantial rate at idle. Today, a hybrid approach would be used, stopping the engine entirely once the battery was charged. The Capstone microturbine, which is a good backup power source for data centers and hospitals, has been used in this role. There's is more of a bus sized unit, 30x60x70 inches. Again, the scaling-down problem strikes.

"Use a Wankel. All the same advantages. They're even replacing turbines for APUs."

Wankels are complex than the successful Capstone.

http://www.capstoneturbine.com/news/video/view/bus.asp

The biggest problem with turbine powered cars was coupling to the wheels. Turbines have two unfortunate properties that make them very unsuited to directly driving the wheels of a car:
1) They spin far too fast, so you have to have a transmission to slow that down.
2) they don't like to slow down too much, so you have to have some means to clutch them so starting from a stop won't stall them.

In applications like helicopters, that's not a big deal: once you have the rotors turning, you'd like to keep them turning.

But for cars it was a deal-breaker.

I highlight was because there is a better idea on the block:

http://www.capstoneturbine.com/prodsol/solutions/hev.asp

The idea Capstone has is that you have a single spindle turbine, with a generator on the same shaft as the turbine. There is no mechanical coupling of torque to the wheels - the system makes electricity. That works well with an electric drive train - electric motors have no problems with making torque at zero RPM, they have a wide torque band that reduces or eliminates the need for a transmission, and the turbine can be started and stopped as needed to maintain the batteries. The Capstone turbines don't need lubrication as they use air bearings, and they meet or beat all the air quality standards on the books or planned to be on the books, running on diesel.

I just hope somebody gets smart, and makes a van chassis on this tech, with different bodies for Suzy Soccermom, UPS, Class-C motorhomes, and basic transportation, that uses heat pumps + resistive heating for climate control (so that it can run off the traction battery without needing to run the turbine to make heat), and that gives me access to 120VAC@50A from the traction batteries (plus an inverter, naturally) so that I can use it for camping as needed.

(no, I neither work for nor own stock in Capstone - I just think this is the way things need to go.)

http://www.capstoneturbine.com/prodsol/

I'm not rich, but some /.ers are. Hang one of these in a hybrid and have at it.

In the 1960s Chrysler developed a turbine engine and drove a car across the country on it. They also had a test program with a limited group. Driving it was similar to a diesel, in that it had a startup procedure one had to follow, but it otherwise operated normally. It got significantly better mileage than cars of the day with excellent performance, but it killed gearboxes rapidly.

More recently and more similarly to this project, Langford Performance Engineering of Wellingborough England modified the Ford S-Max seven seat crossover vehicle into a series hybrid plug in vehicle with a [capstone] C30 turbine, achieving over 80 mpg equivalent in early test driving. This made it a series hybrid like the upcoming Chevy Volt, but more efficient.

And it can be used for Combined Heat and Power which would be exceptionally useful here in Michigan. But that's a 65Kw model which would be a wee bit excessive for your average residence. Efficiency and power output goes way down at ambient temps above 70F, which isn't a problem most of the year in Michigan (11F outside now, and this is southern Michigan). A Combined Cooling Heat and Power setup might be neat further south. They look to be louder and way heavier than the Guardian standby gennies too and I probably don't want to know what they cost. They're all poor substitutes for nuclear batteries of course...

And it can be used for Combined Heat and Power which would be exceptionally useful here in Michigan. But that's a 65Kw model which would be a wee bit excessive for your average residence. Efficiency and power output goes way down at ambient temps above 70F, which isn't a problem most of the year in Michigan (11F outside now, and this is southern Michigan). A Combined Cooling Heat and Power setup might be neat further south. They look to be louder and way heavier than the Guardian standby gennies too and I probably don't want to know what they cost. They're all poor substitutes for nuclear batteries of course...

include scraped content

• Continuously or On-Demand
• Stand alone or Grid Connect
• Individually or Multi-pack
• Run on a variety of fuels
  • Low or High Pressure Natural Gas
  • Biogas (landfill, wastewater treatment centers, anaerobic)
  • Flare gas
  • Diesel
  • Propane
  • Kerosene
  • Flaming Wall St. mortgage brokers and investment bankers

Similar story covered by Slashdot in 2004 (Georgia Tech)

Turbine engines also have many disadvantages too though. Like, they're expensive. And loud. And run very hot. And don't idle well. And suffer from delayed throttle response. And a breakdown will generally be catastrophic.

(1) we have never made any near a century life atomic batteries, and (2) we have never tried to make a generator from this technology.

1. We've made dozens of atomic batteries, both RTG's and reactors, and launched them into space. They work. Making one work for a century is just a matter of engineering.
2. Making a sonic fusor get even to technical breakeven (let alone engineering breakeven) is uncertain and may not even be possible.

(1) we have never made any near a century life atomic batteries, and (2) we have never tried to make a generator from this technology.

1. We've made dozens of atomic batteries, both RTG's and reactors, and launched them into space. They work. Making one work for a century is just a matter of engineering.
2. Making a sonic fusor get even to technical breakeven (let alone engineering breakeven) is uncertain and may not even be possible.

I think you focus on the greater issue of conservation shouldn't be such a microcosm.

The national power grid operates at a whopping 18% efficiency. That's right, 82% of the energy made by power plants is lost to transmission, heat, etc. The real solution to conservation is to use locally-generated power to reduce transmission and heat loss. If homes were using Microturbines, they could generate their own power AND heat their water. From my best recollections, these things get 86% efficiency and generate enough power for 4 homes.

Let's not forget about solar panels (great for the southwest!) and wind turbines (also good for the southwest, and the midwest). Really, if we want to improve efficiency, let's go straight to the source, eh?

* It may do 0-60 in 4 seconds, but so can lots of vehicles if you do hairy modifications to the engine and drivetrain. The car is tiny and light, obviously, since it needs only 200 horsepower to produce those figures.

2450 pounds is not light in my book, though the lithium-ion version is reported to weigh a bit under 2000 pounds. The sparkling performance is due in no small part to maximum torque being available from zero speed, a characteristic of many types of electric motors.

* Note the careful wording: "...Efficiency *to* 70 mpg." That tells me they are taking an average and counting when the motors are off while cruising.

You count the time your engine isn't working on a downslope when calculating your gas mileage, and your car gets its best mileage when putting along on the cruise control too. Not that the tzero's motor shuts off; the tzero doesn't have gears or even a clutch, so the motor is spinning whenever the car is moving.

* Good luck getting a charge when you run out of juice in the middle of nowhere. At least the AAA can bring you a 5 gallon container of petrol with a conventional vehicle.

If these vehicles were common you'd have charging stations everywhere, and you could always accept a partial charge from another vehicle. You know, like siphoning gas only without the risk of fire? (AC Propulsion used to list this as one of the features of their technology, but they've either removed it from their web site or made it very hard to find. It is implicit in the ability to generate AC to back-feed the grid; see the link named "Vehicle-to-Grid Demonstration Project: Grid Regulation Ancillary Service with a Battery Electric Vehicle".)

* A 100 mile cruising range is less than one half of the range of a typical passenger car with an ICE

That's for lead-acid batteries. The lithium-ion version has a range of about 300 miles.

* Totally electric cars are less efficient in the winter, when power is drawn for heating.

That's what hybrids are for. If you are using the hybrid battery in "depletion mode", you just switch over to engine power after you use the battery's non-surge capacity. If you run short distances between charges, that might be never.

* The emissions aren't "near zero," it's just that the extra pollution would be emitted from power generation facilities. Those power generators may be more efficient, but an increase in output (to supply these vehicles) is going to introduce tons (literally) more pollutants into small areas of the planet.

Figures? The typical ICE vehicle runs around 20% efficiency or less on average. If the tzero is powered by combined-cycle powerplants burning natural gas at 50% efficiency and has 40% losses in transmission, batteries and conversion, that's still 30% net efficiency. Plus, the waste heat of the combined-cycle plant can be harnessed to do useful things; you can't do that with the heat coming out of the radiator, exhaust or brakes of the ICE car. And with electric cars and microturbines as co-generating heating plants, the net efficiency of the system can go over 80%.

You can also hook the tzero up to a wind plant or solar panels. 500 watts of solar panels would give you about 12 miles a day. The I

A few years ago, Ben Rosen (yes, that Ben Rosen) started Rosen Motors, which was once at www.rosenmotors.com but that now looks like that URL doesn't belong to him anymore.

He had nifty ideas for gas-turbine-generator/electric-motor hybrid automobiles with high-RPM flywheel regenerators in the trunk, but, you can guess, it didn't pan out as a feasible place for Ben to bet his future. So he downsized the dream and now makes his way selling some of the most efficient fossil-fuel-burning electrical generators the world has ever known, under the name Capstone Turbine.

Google spits out a few gobbets, too:
Speculation, speculation, speculation, and capitulation.

--Blair