Meadwilliam

Fuel cell or internal combustion engine...oxidation is still oxidation.

petrochemist Loc: UK

That is true but the fuel cell is typically substantially more efficient. I'm sure it's not just due to lacking the sound (which tends to be better from internal combustion).

DirtFarmer Loc: Escaped from the NYC area, back to MA

Also, using air in an internal combustion engine can produce oxides of nitrogen, contributing to smog.

John Hicks Loc: Sible Hedinham North Essex England

How big would the batteries have to be to power a large bulldozer, I cannot any batteries lasting more the two hours on a bull dozer.
The only way to have an electric bull dozed would be to ha six foot diameter wheel on it to which an electric cable would be run so that when The dozed goes forward it lets out cable and when it reverses it winds it in again with one end attached to the dozed and one end to a three phase power supply

David in Dallas Loc: Dallas, Texas, USA

My biggest concern would be safety. For efficient storage, hydrogen must be contained at very high pressure. Not only that, it is the smallest of all molecules and very difficult to distribute without leaks. And worst of all, it burns with an invisible flame--something could be on fire and not noticed. I wouldn't drive a hydrogen-powered automobile.

DirtFarmer Loc: Escaped from the NYC area, back to MA

I would think the power requirements of a bulldozer would be similar to a large truck. The truck has to use the power for overcoming air resistance when travelling at high speed. The bulldozer needs the power to overcome the resistance of what it's pushing around at slow speed. It's geared way down. I've never seen a racing bulldozer.

So if we can make electric trucks, it should be possible to make electric bulldozers.
And the size of the batteries isn't that important. Bulldozers need weight for traction and a large battery would probably contribute to that.

John Hicks Loc: Sible Hedinham North Essex England

You are missing the point the reactive effort of a large bull dozed needs to be far higher than a large truck, the resistance to movement of tyred wheels on a road is negligible compared to the reactive effort required for a bull dozed to move a large quantity of soil or other matter.
The bill dozed would have to have a gear box so the the electric motor could turn at speed that the gearbox would transform mechanically to it tracks and batteries would never be able to provide the continuous power needs all day long for the dozed to work. This is why the dozed would need to be connected to a three phase mains supply

DirtFarmer Loc: Escaped from the NYC area, back to MA

Trucks need a lot of power to get up hills so I expect they would need a large engine. Trucks move a lot of weight and that takes power when it’s uphill.The engine speed is not really important because it is geared down in both vehicles. Geared down more for dozers.

And the tire resistance is small compared to the air resistance of a large truck at highway speeds.

Actually I suspect that the large dozers use hydraulic drive systems rather than gear boxes.

Again, I believe that if it can be done for a truck then it could be done for a dozer. In my limited experience with bulldozers they get used in spurts, moving a pile, then going back for another. Trucks run continuously for long times.

I must admit that I have no expertise in battery vehicle design.

macatac

Back in the 1960s there was a guy in Utah that started a company to manufacture buses and trucks that used
hydrogen as a fuel source. He had found a way to safely store hydrogen in tanks using anhydrous crystals.
To provide proof of the safety he set up a demonstration of three tanks of natural gas and one of hydrogen and one of hydrogen with anhydrous crystals. The three tanks where placed in a field and each was shot with a high powered rifle. The natural gas a hydrogen both exploded when hit, however the one with the crystals the bullet went through it with no explosion and a second shot ignited the escaping hydrogen but still no explosion.
At the time there was a Canadian company that was doing research on a high efficient electrolysis units to produce hydrogen, the thought was to use focused solar mirror arrays to produce high pressure steam that would drive turbines for the electricity for the electrolysis.
The USPS became interested and wanted to place an order for trial postal deliverer trucks, but there was never an order placed due to pressure from oil company executives. I remember seeing this on a Merve Griffen TV show where Griffen interviewed this guy and he went on to explain how he and his family were being threatened
and one of his plants had been fire bombed. He just gave it all up. While on this show he started to name some of the oil company executives but the tv network cut the whole live program off. I never ever heard anything more about this.

Bison Bud

Wow, hydrogen stored in solid form as crystals sounds like a dream come true! If this technology indeed exists, then hydrogen as a viable fuel has some real hope. I will be looking into this further, thanks for the info.

Daryls Loc: Waco, TX

Just like with these electric cars, folks are ignoring the inherent 'new' dangers associated with these alternate designs. For the thorium reactors, they produce uranium-232, which decays to an extremely potent high-energy gamma emitter that can penetrate through one meter of concrete. It will certainly travel through your home and car to you! Handling the spent nuclear fuel is also extraordinarily dangerous. Think of a car accident or an accident in your home with one of these reactors.

Many of the thorium advocates say that these thorium reactors produce little radioactive waste. While that may be true in the classic sense, they do produce a different spectrum of waste compared to those produced from uranium-235. Think of the many dangerous alpha and beta emitters, and isotopes with extremely long half-lives, including iodine-129 (half-life of 15.7 million years). These will impact life all around just from normal wear-and-tear with average consumer use.

These types of reactors MAY be a little less dangerous than regular uranium reactors (think weapons-grade nuclear materials, alpha, beta, gamma, neutron, heavy metal poisoning, etc.), but the hazards are still very dangerous, just different dangers and degrees of danger.

Back to those electric cars, first responders get killed responding to vehicular accidents way too often because of the electrical technology and chemicals incorporated in them. So, consider the different dangers when looking at alternatives and not just the potential benefits assumed, IF everything goes right all the time and Murphy stays in his cave. We will all live longer.

Daryl

Daryls Loc: Waco, TX

And it would NEVER work in California. They cannot even manage their electrical grid as it is now without all those electric cars/trucks/etc. Just imagine how bad the rolling brownouts/blackouts would be with more electric vehicles. The same would apply in most, if not all, the USA. And how would we power the generators to produce electricity - windfarms and solar panels? With current technology and distribution systems, I doubt that is feasible.

Daryl

David in Dallas Loc: Dallas, Texas, USA

I don't think anyone is seriously recommending use of thorium reactors to power cars or homes--I think they'd be part of the electrical grid. They do have the societal advantage of not producing plutonium as a byproduct, so are not a source of bomb material.

Daryls Loc: Waco, TX

I sure hope you are right David. That would be disasterous for the world if they used them domestically. Maybe in 100 years or more, but certainly not currently or in the near future.

Daryl

David in Dallas Loc: Dallas, Texas, USA

I think this is a discussion of clathrates. Those are crystal-like structures that can entrap gas molecules. It is a technology that needs further investigation.