Hydrogen is expensive to make.
Hydrogen is expensive to distribute.
Hydrogen is hard to hold onto and makes many metals brittle.
Fuel cells are expensive.
Fuel cells are fragile.
Fuel cells generate electricity so that the has to be expensive and inefficient or have an electric motor.
A heat pump is a constant load load device making it easy to run the diesel engine on alternative fuels.
They are trying to fix a 2 dollar problem with a 10 dollar solution. There are better and easier ways of dealing with the problem.
I would prefer to add pneumatic regenerative braking to the trailer compressing air to a very high presser and use the expanding gas to
cool the cargo. In the name of efficiency I will use the cold from the expanding gas as it drives the compressed air engine that drives the heat pump to to help the heat pump cool the cargo. This design will also save brake pads and provide compressed air for the tires.
26th August, 2013 @ 11:24 p.m. (California Time)
slowburn, there are a lot of advances in fuel cells.
The are making newer fuel cells that do not cost a lot. There are ways to produce hydrogen that do not cost a lot. There are even home refuelling stations that are affordable. Fuel cells have become sturdier and smaller. Ways to store hydrogen has improved.
I think this is a good idea. The only exhaust from a fuel cell is water. It is very green. I think it is the way of the future.
27th August, 2013 @ 5:30 a.m. (California Time)
Regenerative braking would be fine up to a point.
Trouble is, these trailers spend a significant part of their daily work cycle stationary, and whilst when at their base they could plug in to mains electricity, when spending the night at a truck stop it is unlikely that they could access mains power. However, a non-diesel powered refrigeration system would be more welcome by other truck drivers- many of whom have lost sleep at truck stops when a 'reefer' parks up next to them because of the very intrusive noise.
There are existing production fuel cells that run on ethanol which would probably be a better fuel than hydrogen, as ethanol is pretty cheap to produce (it can be produced from waste vegetable matter).
27th August, 2013 @ 6:53 a.m. (California Time)
Using fuel cells just seems foolish to me. Why go through the effort of creating an expensive difficult to fuel device like fuel cells for cooling when we have absorbtion chillers that can do the trick with basic science and the waste heat in the vehicles exhaust?
You just build the chiller in the trailer and a heat collection system in the exhaust of the truck and use a non boiling fluid as heat transfer medium to the trailer unit. Or you could reverse that and put the chiller at the exhaust and have it cool a non-freezing solution and deliver chilled coolant to the trailer.
27th August, 2013 @ 6:56 a.m. (California Time)
Slowburn sounds like he's on the payroll at Exxon. I've never seen someone poo-poo such a tiny little trial program so profoundly unless they have an agenda.
If we always listened to the naysayers, where would we be now? Progress is made by programs like this. Appealing for the status quo never got us anywhere.
27th August, 2013 @ 8:16 a.m. (California Time)
What about your agenda Stradric?
While you might disagree, at least he made logical points and offered up an alternative- without resorting to name calling.
27th August, 2013 @ 9:45 a.m. (California Time)
Using platinum as the catalyst to generate 1 watt second of hydrogen from water it takes 1.8 watt seconds of electricity, and then you have to compress it. I generate a little hydrogen for floaty balloons by using waste caustics on trash aluminum foil (the scrapyard does not accept aluminum foil.) but I would rather see the aluminum reused. I was thinking that adding the foil to the alumina mix at the smelter could solve the difficulties and still save energy in producing useful metal.
Part of the fragility of fuel cells is their susceptibility to being poisoned.
These trucks weigh about 70tons loaded slowing them down can provide a lot of power and it can be stored pneumatically faster than in can as electricity.
The diesel powered reefers I have heard in the last 20 years are pretty quit. American truck stops are already providing in cab climate control, electricity, and entertainment at lower cost than idling the truck I do not see any real difficulty in adding enough electricity to drive the reefer as a problem.
Purifying the alcohol is an energy intensive process.
My agenda is to exchange information and opinions to teach and learn. Suggesting alternate fuels for the existing engines, and an alternate engine that DOES NOT USE OIL is not "Appealing for the status quo" and pretty much proves I don't work for an oil company. Do you work in the Fuel cell industry or do you just think fuel cells are really cool?
I think that using gamma emitters to generate heat in tungsten to power an ammonia absorption or Stirling Cycle engine would be really cool but in the current terror environment I don't want to see thousands or even dozens of them on the road.
27th August, 2013 @ 12:03 p.m. (California Time)
H2 used in fuel cells is very efficient,we already use vast amounts of it.Next gen nuclear plants can produce H2 with no CO2,this is an excellent demo.
27th August, 2013 @ 6:40 p.m. (California Time)
Can you tell me where this "green" fuel source of hydrogen that we use comes from?
28th August, 2013 @ 7:45 a.m. (California Time)
Seems to me there is a lot of real estate on a truck trailer, and solar would be a good alternative. It could be used to run fans,charge (one or two) batteries required by the truck and it's reefer . and peltier junctions, all reducing the run-time and load on the old faithful back-up diesel cooling/heating system.
Regenerative systems is a great idea, but when it comes to brakes I think KISS is the best idea, I could only imagine the hardware needed to accomplish this task, and the crazy amount of service required to maintain it . Now if it could be mounted on the 5th wheel truck tractor mount that might be something simple that could help generate that free lost energy. but might have a negative effect braking and steering ? I'm not that smart but am willing to practice on someone else's equipment, just not mine !
All I require to do this is free beer and a open checkbook.
28th August, 2013 @ 8:55 a.m. (California Time)
@ Jay Finke
Solar is fragile, heavy (Especially when you include the necessary batteries.), and increases the height of the truck increasing aerodynamic drag.
28th August, 2013 @ 4:32 p.m. (California Time)
I did not suggest using a bunch of batteries, using solar to supplement power produced by the reefer and vehicles alternators witch can consomme considerable amounts of power from the engines+ belt wear. they make flexible panels now that would maybe a 1/4 inch to the height, Ideally the trailers should have the panels built in during production and being that solar is DC it's a perfect fit.
And a square box going down the road is not known for it's amazing aerodynamic qualities, so we have to work with what we have, solar seems to me as the smart safe thing to do rather than messing with the simple braking system that time tested true. don't get me wrong I like the regenerative system, my only concern is safety and maintenance costs, all of this breaking system would need to be DOT approved and I think might add lots of weight, as truck working air pressure is 125lbs and to make the regenerative system feasible would need to be in the thousands, the tanks required to hold this amount of pressure are heavy. thus reducing payloads.
solar is light and virtually maintenance free and last about 20 years outlasting the trailer life cycle, and would make great storage facilities in there next life do to it's own built in power supply although diminished but able to support lighting and some sort of climate control. .
29th August, 2013 @ 7:30 a.m. (California Time)
Because a trucks aerodynamic efficiency is limited by the utility of the cargo space making it worse is ok? I don't think so.
So after adding the expense of the solar if the truck driver wants to sleep at night he has to run his engine or find an electrical outlet.
Now I assumed that in purpose built trailers that the carbon fiber tanks would be part of the structure. And even as a retrofit it would be inside the aeroskirt.
The trailer would still have the original brakes so DOT approval should not be a problem especially if you have just substituted a drive axle to get the power takeoff.
29th August, 2013 @ 1:43 p.m. (California Time)
Solar is not going to effect noticeable trailer capacity, do to its thin design and light weight, and all it does is help support the trucks electrical system, so it's not some crazy huge solar array. And the cost and availability would be cheap and easy to install. also make for quick engine stars, reducing wear on the 100 amp alternator and the starter on the truck. Once again, I state.. it is a support system for the truck and reefer electrical system. Reducing the load on the engines so they can do the job of pulling the trailer, and cooling/heating the reefer.
And exactly how much air would you need to run a reefer over night, and what is converting the air into usable power source ? you could use a air starter off a old Mack truck, there a quiet source of power.
carbon fiber tanks must be DOT approved and are Crazy expensive, and would need to be huge to store air required to be effective.And need to be re-certified every 10 years sure aroskirts add up-to 3% added efficiency but have a cross wind problem, there are other devices that redirect flow around the back of the trailer, that avoid the nasty cross wind effect of skirts.
drive axle on the trailer ? the only drive axle is on the tractor and would cause excessive tire wear on the owners truck (the guy who buys the tires) and might effect breaking unless anti lock breaks are tied into the system,
I think a solar unit could cost around $2000.00. what do you think the system you are suggesting would cost ? and where exactly does this "substituted a drive axle to get the power takeoff" fit in ?
30th August, 2013 @ 11:33 a.m. (California Time)
@ Jay Finke
By using an axle that all ready has the hardware to run mechanical energy between the input/output shaft and the tires, I use off the shelf components saving time and money in the design process.
You say the cost of solar has come down. So has the cost of carbon fiber.
You picked the the loudest pneumatic engine you could find in your argument to support an expensive system that saves a little wear on a generator. and judging from the area of solar panels to provide air-conditioning for the driver there is no way that covering the top of the whole trailer will provide enough energy to power the reefer to merely fresh food temperatures.
30th August, 2013 @ 2:27 p.m. (California Time)
What axle are you referring to ? the only ones are on the tractors drive wheels with input/output shafts = tire wear, not popular with truckers. and attaching a drive to a drive shaft would cause a side load, and would need to be belt or chain drive,
Carbon fiber is used to cover aluminum tanks..., to straighten. I was unaware that carbon fiber was used to make a complete tank, and carbon fiber covered tanks add about 500% more to the cost over a aluminum tank.and once again have a working life of only 10 years and cannot be re-certified, and as a bonus must be inspected annually.(DOT) I think you will find there is no way to store enough air to run this type of device for more than a hour at best at a rest stop, and that's being optimistic.
A 2000 watts of solar is not going to cover the trailer, just a portion of the roof and would make a great maintenance free quick and easy support system for the entire trucks electrical system. saving on batteries and alternators
what do you propose to use as a air engine, and the starter, I didn't find it I had one, and they are no louder than a train horn. and fun to start in parking-lots with unsuspecting walker buys.
A spring seems to be a better idea, the trucker could wind it up at the rest stop every few hours.
2nd September, 2013 @ 9:07 a.m. (California Time)
@ Jay Finke
To harvest energy from braking the trailer One could design an entirely new idler axle, or take an axle that is already in use has conventional brakes and everything that works equally well transferring energy from the drive shaft to the tire or from the tire to the drive shaft. Being used only as a brake means that no extra tire wear will take place. Just as an aside driving in icy conditions One might find oneself with the drive tires on ice and a littler extra push might be pleasant, but I am certainly not going to go to any effort to build it into the original test articles.
Carbon fiber tanks have an aluminum bladder it is no more a pressure tank than the inner tube in a bicycle tire. I am going to assume that you looked at the size of scuba tanks to come up with your estimate of available energy. For the test article If i could get a good deal on them I would use maybe 30 of them. I expect with the right backing the tanks manufacturer could vary well loan me the tanks in exchange for buying all the production tanks from them for a number of years. (Best to have the business manager take care of the contract.)
The production tanks would be about .6m in diameter and 6m long and built specifically for the purpose. The real advantage of carbon pressure tanks being that they are light. This is generally only an issue in tanks that are going to be constantly moved making it almost inconceivable that the tank would not have to be designed for the purpose; this is why the manufacturer would be willing to deal on the tanks for the test article.
Your solar system provides electrical power for the trucks normal system this is about a non-diesel powered reefer which your solar power system does not come close to generating enough power for.
Your pneumatic starter motor is great for what it does but is not designed for efficiency or quit operation; it vents air at high pressure without a muffler. The pneumatic motor for the reefer would vent the air at only slightly above ambient pressure and have a muffler making it almost silent. Also because of the temperature drop from expanding a gas which my design would harvest for cooling the cargo means that the reefer's heat pump is much smaller than an equivalent Diesel powered reefer.
3rd September, 2013 @ 8:30 a.m. (California Time)
A tag axle, is all and good but would be on the trailer right, so much for off the shelf items, and might cause a dag on the trailer, might be a safety issue on icy conditions along with the air lines freezing up, and this would have a electrical system from Hades to control this system. sounds like you might need extra power to support this system ? the solar might come in handy ?
So your tank contains moisture, and the pressure needed to support a system like this would need to be in the thousands, that's a multi stage compressor A BIG one . and at what cost . if a tank that could hold 20,000 psi is available, it seems this idea would be feasible,
I like the regenerative braking idea, and it seems the only efficient way to do it is with batteries, making the air system possible but not probable.
This air system is not off the shelf, and would cost tens of thousands to implement. As the solar system could be in service yesterday, and could be installed at a reasonable cost that could implemented on tens of thousands of trucks in a mater of weeks, showing a instant savings on fuel consumption, although small but would be big in the ln the long run.
That's why we are here to hash things out, and hopefully come up with a great idea, This is why mechanics and engineers should work together.
4th September, 2013 @ 9:17 a.m. (California Time)
@ Jay Finke
In what way is a drive axle not on off the shelf component every truck on the road has at least one. I will be using them in a unconventional manner but exactly the same way that a compression brake uses them. I can probably even find off the shelf locking differentials for them if I check out enough off roading shops and and then select the axles to match.
A compressor does not care how the mechanical energy is delivered as long as it meets the requirements so I can power compressors by harnessing a team of kangaroos if i have the time, money, and the mind altering drugs to make it seem like a good idea.
I am trying to power a heat pump with a second heat pump and am extracting cooling from both. So I don't have to generate as much energy
as it takes to power a conventional refrigeration unit.
Your 2000watt solar system would provide about a tenth the power the reefer needs at noon in Arizona on a clear day. My 4500psi pneumatic system could store enough energy to power the reefer over night.
Your arguments don't appear to be relevant to non diesel powered reefers did however lead me to an interesting improvement. I could harvest C02 from the tractors exhaust and save a bunch of weight and energy in the compression and storage of the working fluid.
Probably less practical is how much low presser storage would it take to contain the refrigerant spent cooling the cargo for 15 hours.
6th September, 2013 @ 3:47 a.m. (California Time)
A axle is made to drive the truck is way too big for this system, and would cause drag do to its size and may be dangerous in icy/wet conditions.
4500lbs is no joke and must use DOT certified tanks and should be certified to burst at like 8000psi,those sound cheap? the compressor to operate this would cost Thousands and is fragile as it is a multi stage pump that creates a huge amount of heat compressing the air in stages.( search scuba tank compressors) the last piston stage of the compressor is the size of a pencil, that's 4500 lbs we are talking about that's allot of kangaroos ? hi pressure comes with great costs ! and the air entering a high pressure pump needs to be squeaky clean ! and the amount of hardware to operate this air system just boggles the mind. may I suggest the KISS system instead.
Seems engine breaking would be easier safer source of pressure, but in no way enough to support this system, at best it could be a support system.
may I suggest the KISS system instead. SOLAR support light/cheap/simple. if I remember right there are 800 watt panels a few years back, that are 4x6, that's about 12,000 watts.
POOL PUMPREAPAIR guy longwood
9th September, 2013 @ 12:10 p.m. (California Time)
@ POOL PUMPREAPAIR guy longwood
Simplicity is nice when it works which would be a good reason to leave diesel reefers alone.
I said that I would be powering a heat pump with a (open cycle) heat pump (I forgot to mention the open cycle hangs head in shame) So I clearly know that compressing air generates heat. I generally prefer to harvest this energy through a Stirling Cycle engine but there are times when just dissipating it is the better option.
12,000 watts still falls short of being able to drive the heat pump on a standard reefer unit. If I am going to use stored electricity to power the reefer when the truck is not moving I will still go with regenerative braking because it costs less and is lighter.
Another option to store large quantities of gas compactly and at lower pressure is to combine nitrogen and oxygen into nitrous oxide and compress it to a liquid like C02. Then when cooling is needed boiling the liquid off as a source of refrigeration, and then using a heated catalyst to decompose the gas back to nitrogen and oxygen producing large quantities compressed air for driving the conventional refrigeration system.
10th September, 2013 @ 11:41 a.m. (California Time)
I seen awhile back that they are using DC scroll type compressors on hybrid cars, this might be a option, seems to me the compressor was variable speed and the size of a beer can.
dc motors have came a long way in the last few years, along with ac pumps, this makes me wounder how long one or two of these hybird car batteries could run a efficient dc motor attached to a scroll type compressor w/ the solar charging ?
Oxygen is a dangerous gas to be using, when exposed to flames it magnifies the fire. I use oxygen for my torches at my shop to cut steel 2 inches thick with ease., and it too also has all sorts of DOT issues, oxidizer ?
12th September, 2013 @ 11:13 a.m. (California Time)
@ Jay Finke
Any type of compressor can be used with the pneumatic system.
With out batteries solar is daylight only.
Light weight batteries are an explosive when charged.
14th September, 2013 @ 2 p.m. (California Time)
Storage of air is the issue with the pneumatic system, and it seems battery type system would be smaller,lighter and simple.
any automotive battery can be explosive,but seems to work well in the hybird cars, seems if the pneumatic system is such a good idea, why don't they use it in cars ? testing needs to be done on both,to see if ether are possible.
14th September, 2013 @ 5:23 p.m. (California Time)
@ Jay Finke
Because the government subsidies are for EV and E hybrids not the best tech.
16th September, 2013 @ 10:23 a.m. (California Time)
Early prototypes of an air-powered vehicle go back to the middle of the 19th century, even before the invention of the internal combustion engine.
I certainly hope your new idea takes off
check out this new article from gizmag Plasmonic nanostructures could prove a boon to solar cell technology.
17th September, 2013 @ 7:26 a.m. (California Time)
@ Jay Finke
Double the efficiency of solar cells will power the reefer during the day but night is still a problem and stored electricity is more dangerous than stored compressed air.
17th September, 2013 @ 9:05 a.m. (California Time)
Stored electricity is more dangerous than stored compressed air. Huh ? you mentioned 4500 lbs of stored air, that sounds totally safe, not to mention the need for a huge tank needed to supply this device, but not to worry as the tank will be DOT certified, so nothing could possibly ever go wrong.
The batteries are small and can be tucked away safely. And I have know idea how long my DC system will last without testing. I need funding, and lots of it ! cash works best.
17th September, 2013 @ 11:10 a.m. (California Time)
@ Jay Finke
With the batteries you get a boom and fire with the compressed air you only get a boom.
The batteries loose capacity with use the air tank does not.
How have you missed that the trailer compresses the air while braking?
17th September, 2013 @ 10:22 p.m. (California Time)
compressed air you only get a boom and metal+carbon fiber shrapnel ! scuba tanks must be filled in water or a explosion proof container, I have seen a tank that had exploded and it was only 2000 lb tank, and speaking of fire, a moderate air leak can fan a small fire into a raging uncontrollable blaze like a cutting torch that is so hot it can melt steel, you mentioned 4500 lbs and that is a crazy high pressure, hydrogen compresses at 5000 lbs of pressure.
once again your tank idea is only good for 10 years and must have inspections, a visual and hydro testing regularly. unless you use a steel tank., they require less maintenance.
Yes I have pondered this breaking idea before, and was left with the above minor issues listed above. I wish it was that easy, but it's not. air powered car http://www.gizmag.com/go/7000/
18th September, 2013 @ 9:03 a.m. (California Time)
Novel Ideas are "a dime a Dozen".
Here's a novel one...
Refrigerated vans/trailers/call them whatever you like, traditionally run their dedicated diesel motor "all the time" (except for when the thermostat shuts it down).
Using hydrogen fuel cells means that the system is being converted to operate on electricity, as the output of a hydrogen fuel cell (indeed most fuel cells) is electricity (for the layman)..
(storing the hydrogen for a long haul is a little like storing a huge volume of air, a volumetric problem)
While the truck is running, the power needed for the refrigeration unit is likely to be "negligible" (compared to the traction motor's fuel consumption), so why not use a generator connected to the truck's PTO (if the truck doesn't already have a suitable generator) to run the fridge unit while the truck is in motion? (reason why not is additional weight, and the systems in place are fairly efficient and designed to do the task at hand)
People wanting to use regenerative braking, don't really realise that while a braking truck could generate significant amounts of energy, most of the time that the fridge unit will be operating, the truck will be cruising or stationary (hence no regen power).
The use of some sort of silent and nearly pollution free (at point of use) fuel cell for the stationary refrigeration does seem a good idea, however it may be that the use of a high temperature fuel cell running on methane will be a better idea, an absorption chiller will be able to use the electricity generated by the fuel cell to run circulation pumps etc and the hot side of the fuel cell can provide the energy for the evaporation side of the heat pump (that is IF the high temp fuel cells can be manufactured to withstand the rigours of a mobile device.).
Methane (or other liquefy-able hydrocarbon) has a much higher energy density than hydrogen meaning that the storage and transport of the fuel is easier (more efficient) and the majority of the hydrogen produces for industry (just like ammonia and industrial ethanol / methanol etc) is manufactured out of methane, with the CO2 dumped to the environment producing a "clean fuel", which isn't actually a clean fuel.
Using AIR powered systems may seem like a great Idea, but it will add inefficiencies all the way along the line (pun intended), remember compressed air isn't a power source in the way that fossil fuels are (they release far more energy than what we put into them), it is really only a temporary energy carrier/battery with significant losses.
We can all come up with some sort of energy device for powering the refrigeration unit while the truck is in motion: ...[Note that ALL drag devices actually use the main propulsion motor for their energy, so it is better to use the crank-power directly rather than add other inefficiencies such as tertiary level geared systems or dragging tyres for "generating" the needed power.]...
The real need for these systems (where the fuel cell comes in handy) is during the rest breaks while the traction motor is shut down, so we end up needing a stationary form of energy for the ancillaries (including refrigeration and cab air conditioning), this energy is currently all provided by dedicated diesel engines. In the case of a fuel cell powered unit, as the compressor motors will be elecric, IF a power socket is available it will be a simple thing to plug it into the grid and save that valuable hydrogen for down the road.
Flexible power options are going to change a lot of how we power many devices, Fuel cell, is cool, so are batteries (for the correct application) so are liquid fuelled generators. However the current system will work better than using a stationary diesel powered generator to provide electricity to run the refrigeration compressors (count the energy conversion stages).
I'm all for experiments and studies this is how we got to where we are concerning technology. If this is economical people will be all over it, if not then it will fail.
NB: While hydrogen is far from an ideal transport fuel (for some of Slowburn's talking points), I think that its handling problems (such as hydrogen embrittlement and grain boundary porosity) are way overstated. There are examples of hydrogen storage devices being in use for decades with no embrittlement or increased porosity, and the storage containers are not made of any exotic materials, merely low carbon steel (high strength steels (>1000MPa UTS) may be affected in some conditions). Most of the times that Hydrogen gets referred to, in relation to metal fatigue/failure/etc (metallurgical terms),
are cases dealing with extreme high or low temperature environments or with failed welds. The hydrogen embrittlement and porosity in welds is often related to poor welding techniques, preparation or manufacture and storage of the materials used in the welding process, not from being in contact with hydrogen.
To avoid hydrogen embrittlement careful selection of material and careful treatment of susceptible materials is needed. Surface coatings (designed to stop the problem happening with high strength and hardness steels), welding and other manufacturing processes are linked many of the reported conditions of hydrogen embrittlement. It is largely a manufacturing process problem.
OK use of low strength steels may reduce the problems, but they they are heavy and not desired with transport applications (leading to resistant metals and carbon/kevlar filament reinforcing for transport tanks). Austenitic Stainless steels, Titanium, Alumin(um)ium and copper alloys are deemed useful in hydrogen storage and transport applications (maybe the copper isn't so good for high pressure systems).
Note also that Natural Gas as transported in conventional pipelines may be more than 20% hydrogen gas.
Call me crazy, that's OK, but if you read all that I would say that you are also a little crazy. haha. What a waste of time (though I find the research to back up preconceptions worth my evening hours, hey it is better than watching mindless TV.
28th February, 2014 @ 2:25 a.m. (California Time)