Wood burning train

Ray55

I understand a railway locomotive generates about 4 MW of power. Also understand that an area of about 130 acres of trees (high density) can generate 1 MW of power from a wood-biomass based power generator.

As railways normally have a lot of land, can not the land adjoining the tracks be used to grow trees which can then be burned inside the locomotive (a la steam engines) and thus power the train. The waste heat produced by the steam engine can be used by vapor adsorption chillers to provide air-conditioned travel for passengers.

This would make railways carbon-neutral and maybe reduce fuel costs in the long run.

Is this feasible?

Pkruse

Locomotives and ships converted away from coal and wood burning engines mostly because the labor costs were much less with either a diesel or a gas turbine. This is the same reason ships got rid of their sails.

Integral

Actually there is work being done on a eco friendly steam locomotive.

NascentOxygen

Are you saying that a plantation of 130 acres of carefully-managed timber can sustainably (year in, year out) supply all the lumber needed for a 1MW wood-burning power station? So it would be converting solar energy into electrical energy?

I think they end up using more energy (fuel) for the planting, cultivating, harvesting machinery and transport, and processing, etc., then the lumber produces. (A similar situation applies to growing sugar cane to produce alcohol to use in place of petroleum-based liquid fuels. When all is said and done, the nett energy balance is a negative. Only generous government subsidies conceal this sobering fact.)

sophiecentaur

This question fails to say how long the 130acres of trees can provide this 4MW of power. There is a very significant difference between Energy and Power and you should always bear this in mind.

To be fair, though, you are in good company. An idiot energy minsister (UK), on the Radio 4 Programme 'Any questions", today was heard to refer to "storing Power" generated by wind turbines. What a pratt. And he's responsible for a vital part of our economy.

russ_watters

If that was supposed to be 1 MWh, then what it is saying is that a single train would burn 130 acres of wood per hour or if it ran at an average of half power for half the year, a single train would burn 285,000 acres of wood per year. And how long does it take to regrow the wood? 10 years? So to sustainably keep 1 train running, you'd need 2.85 million acres or 4450 square miles, which equates to a coast-to-coast swath of land two miles wide. For one train.

sophiecentaur

That's my garden gone, for a start!

russ_watters

Hmm....Google: wood is 16 MJ/kg, 700 trees/acre. Assuming the average tree is half a meter in diameter and 10 m high and has a specific gravity of 0.5, that's 39 kg per tree, 28,000 kg per acre or 122 MWh. Assuming 33% efficiency, that's 40 MWh. If it takes 10 years to regrow, that's 4 MWh/ year.

So that's off by a factor of 4 from the OP's factoid, but for pulling the numbers out of the air, I don't think it is too terrible. Wikipedia didn't specify if the wood had been dried, which could explain much of the difference.

russ_watters

The OP believes the railroad companies own large amounts of land along the tracks. Not large enough, I would think.

sophiecentaur

Sounds a bit like the Old West and the race from coast to coast!

NascentOxygen

39kg?

I think your old abacus is short of a bead or two, Russ.