Diesel-Solar Hybrid, is it possible?

[GP-9_Man11786]

I was day dreaming on my lunch hour today and was wondering if it were possible to build a diesel-solar power hybrid locomotive. It seems simple enough to mount a solar array to the roof of a locomotive.

It could save fuel one of two ways. First, the solar cells could be used to power auxilary systems such as lights, climate control and the control system. The prime mover would only need to power the traction motors. With the additional loads lifted, less power would have to be generated by the diesel engine.

Option two would send power from the solar cells to the traction motors, also removing strain from the diesel engine.

A third use for solar cells could be to provide head end power to commutor and passenger trains.

I would think the two big roadblocks would be cost (solar pannals cost a fortune). Also solar cells are fragile and would probably break in a railroad environment.

This may seem like a crazy idea but railroads have done crazy things in the past. Look at New York Central'sjet-powered RDC or South Africa's Condensing Steam Locomotive that condensed exhaust steam back into water and re-used it. The question is, could it be done?

[arkansasrailfan]

I think the surface area of the solar panel would be too small to power all the systems you mentioned.
If solar panels could collect enough power, then we might see some on locos. They are used however, to power trackside devices, like card readers, hot box detectors, radio transmitters, oilers, but not railroad crossings

[tree68]

Take a look at those little yard lights - which won't even make it through the night unless it's a really sunny day - and the draw there is an LED or two.

It would take a rather large solar array to provide any sort of useful charge.  Digging a scientific supply catalog out of my recycle pile, I find that one model of solar panel available there could fit 8 panels per square foot.  Using the 7.2 volt @ 100ma panel, with each square foot wired in series to generate 57.6 volts, all of the 1 sq ft cells wired in parallel, and assuming a total solar cell area of 6' x 30', we'd have that 57.6 volts at 18 amps.  Some rearrangement might yield the 74 volts you need for the lights and radio, but at a little more than 14 amps - not enough to run the radio, and possibly not enough to light even one pair of headlights.

There could be a solar solution, though.  It would have to involve a fixed solar installation and the ability to store the power (batteries).  That power could then be used to top off the batteries in the locomotives during idle periods. 

It's possible it would be better to simply power the facilities, however, and leave the hybrids alone. 

[CNW 6000]

What about an AC or DC GEVO or ACe kind of engine that has catenary towers that retract? 

[tomikawaTT]

What about an AC or DC GEVO or ACe kind of engine that has catenary towers that retract? 

In my experience, catenary towers are fixed structures that support overhead wire (catenary) for the benefit of electric locomotives.

Do you mean pantographs?  They don't exactly retract (into a closed fairing - aircraft usage.)  They can be dropped, or folded down, out of contact with the overhead.

Chuck

[beaulieu]

Surprisingly the Italian Railway (FS) is doing something like this with some of their electric locomotives. They have a solar array on their roof between the pantographs to provide power to auxiliary systems when the pan is down, reducing strain on the batteries, the power generated charges the batteries, kind of like a UPS for the locomotive. The biggest problem will be vandalism, If you have seen the graffiti on Italian locomotives you will know what I mean.

[Railway Man]

The biggest problem will be vandalism ....

Not to mention theft and dirt.   One of my peers told me a few weeks ago that to protect dinky little 50-watt solar panels from theft on his railroad, he is mounting them on 40-foot high concrete poles with concertina wire embedded in them.  The pole can still be knocked over, but the panel won't survive. 

The grime and dirt issue is not small -- you have to keep the panel clean or the efficiency goes to zip.  On the roof of a diesel locomotive?  That ran through tunnels?  It would have to be cleaned almost daily!

RWM 

[TH&B]

Well one advantage to trains is that if your railway is electrified with catenary then your power source technoligy can be anything your heart desires.  You could then run a solar/ diesel train, although it's not realy solar/ diesel locomotive as such.

[cprted]

Solar panels really aren't an efficient way of powering anything more than a cooler at a cabin with no other source of power. Food for thought: it takes about the same amount of energy to build a solar panel as that panel could ever generate in its life span.

[Andrew Falconer]

If you are looking to produce fuel locally then you have to rethink the concept. 

The Photovoltaic panels would work best on the top of most buildings where they are used to generate the electricity that will crack purified water into Hydrogen and Oxygen gasses. Then Hydrogen and Oxygen is loaded into the Locomotive's fuel tank. Eventually the gasses are recombined in an internal combustion engine or an electrical generation combination chamber on the locomotive.

Each piece of equipment can only do so much.

Andrew

[erikem]

I think the surface area of the solar panel would be too small to power all the systems you mentioned.

A quick sanity check. Let's assume that we have a 70' loco with a full width body and half of the area is available for solar panels (0.5 x 70' x 10' = 350 square feet). Let's also assume that we have solar cells with 50% conversion efficiency (demonstrated in the lab, but years away from production). Insolation in places like Arizona maxes out at a bit over a KW per square meter (about 100/sq-ft). This works out to be 17.5KW, which isn't enough to run the auxiliaries on most locomotives - and that's with wildly optimistic figures for available area for solar panels and solar cell efficiency! Couple this with average insolation being about 1/4 of peak insolation and the idea looks like a non-starter.

[arbfbe]

Modern diesel locomotives have prime movers which output 4000 to 4400 hp.  Now how many square feet of solar cell surface is needed to generate that kind of wattage?  What happens when the sun goes down, the locomotives go into a tunnel, it starts snowing like crazy or it rains like cats and dogs?  The loco cannot carry enough batteries for events like this even if the solar panel array could generate enough power in the first place.

So forget this idea and move on to the next.

[Anonymous]

I saw a video presentation on TED.com by Paul MacCready: Flying on solar wings.

http://www.ted.com/index.php/talks/view/id/176

Paul is famous for inventing the 1st human-powered airplane. Now he has built a plane that flies on solar power. the video is amazing! If this can be done for an airplane, it could probably work for trains. Of Course, the lighter weight construction and lessening any wind resistance on the trains would help. 

Check it out, maybe the Howdy Doody mobile will fly yet!

Neriah Lothamer 

 

[tomikawaTT]

I saw a video presentation on TED.com by Paul MacCready: Flying on solar wings.

http://www.ted.com/index.php/talks/view/id/176

Paul is famous for inventing the 1st human-powered airplane. Now he has built a plane that flies on solar power. the video is amazing! If this can be done for an airplane, it could probably work for trains. Of Course, the lighter weight construction and lessening any wind resistance on the trains would help. 

Check it out, maybe the Howdy Doody mobile will fly yet!

Neriah Lothamer 

If you're referring to that huge 8-engined flying wing that's designed to fly at some preposterous altitude for maximum solar panel efficiency, the whole aircraft weighs less than a single coupler on a modern U.S. train.  Sort of like trying to heat your cabin in Maine by burning individual kitchen matches in your wood stove, when compared to the power requirements of a PRB coal unit.

Chuck

[erikem]

Modern diesel locomotives have prime movers which output 4000 to 4400 hp.  Now how many square feet of solar cell surface is needed to generate that kind of wattage?

4000 hp equals 3MW (3,000 kW). Currently available solar cells produce 20 watts/sq-ft or less (depending on time of day, type of panel, etc). That's 50 sq-ft per kW or 150,000 sq-ft for equalling 4,000 hp - that area is about 3 1/2 acres (and this is assuming the best terrestial solar cells). Would make more sense using stationary solar cells and distibuting the power via catenary.

Batteries are getting to the point where a battery powered locomotive is technically possible, but may be quite a while before it is economically feasible. Li-ion batteries are good for 200 w-hr/kg, so 90 metric tons on a locomotive would have a capacity of 18 MW-hr, or the equivalent of a 4,000 hp locomotive in run 8 for 6 hours. 

[carnej1]

 I guess if it can be dreamt off, somebody will create a website about it...

http://solarsteamtrain.com/cms/component/option,com_frontpage/Itemid,1/

While not a Solar/diesel/hydrid, still interesting...

[tree68]

  I guess if it can be dreamt off, somebody will create a website about it...http://solarsteamtrain.com/cms/component/option,com_frontpage/Itemid,1/While not a Solar/diesel/hydrid, still interesting...

And notable in that they are working within the design parameters of the locomotive, using the solar to create the steam for the fireless cooker. 

The question will be whether they can generate enough steam to do the job, and how long they can maintain the stored steam in their fixed plant. 

[Modelcar]

.....In this non railroader's thoughts....The most sense Iv'e seen lately in fuel saving designs is the 3 gen sets per loco and only as many on line for current work being done.  Automatically and seemless start / stop operation as needed.

At this point in time...we do not have the units in production to come anyway close to providing enough elecricity {converted from the sun},  to do much benefit to operating a locomotive.

I'm certainly not against solar....Bought stock in it 30 plus years ago.  It really hasn't made it yet over the wide spectrum.