No-one would have mentioned the Toyota Pious if only you hadn't introduced yours into the discussion. However, as an aside, the Clarkson is correct. As much as his on-screen persona is to appear to be an arse and as offensive as possible, wider research shows that he is actually very well-informed.
The key to increasing fuel mileage has been well understood for very many years, and the answer lays in reducing weight, aerodynamic and mechanical drag, and in using highly efficient power plants. Hybrids are not a very good option because although they provide some efficiencies (e.g. by taking advantage of the different characteristics of petrol and electric motors), they are needlessly heavy and complicated machines and are consequently outperformed by conventional cars such as VW's Bluemotion range.
While I'm on a rant, I mentioned before about the blind alley offered by hydrogen fuel cells. Today I had to take my bike into the shop for a bit of fettling and, while I was waiting, I dived into an old copy of Bike magazine that was lying around in the waiting area. Contained within this publication was an article on an experimental Suzuki Burgman scooter that used a hydrogen fuel cell.
Now, I have already hinted at one of the reasons why it is a very bad idea but this article contained another very good reason, and that is efficiency. This article quotes an expert who states that refining, storing and transporting hydrogen requires so much energy that less than a quarter of the energy required to get hydrogen fuel into the customers vehicle would be available at the wheel. However, if this energy was put into the National Grid instead and used to charge up a battery electric vehicle approximately two thirds would be available at the wheel. This makes battery electric vehicles three times as efficient and only a third as polluting to run as equivalent vehicles powered by hydrogen fuel cells. This is an appalling statistic and certainly should make people think twice before proclaiming hydrogen fuel cells as being "zero emissions" or even the solution to the impending energy crisis.
But to bring this post back to the topic, the lessons learnt by the car industry should be understood also by the rail industry. For greater efficiency we need lighter and more aerodynamically efficient trains that take full advantage of efficient power and propulsion systems. We also need to be driving ahead with rail electrification in order that more of the network can be run from renewable energy such as wind power that is completely carbon neutral. Storage of kinetic energy using flywheels or battery banks to be fed back in as part of the acceleration phase does need to be considered, but only if the penalty in weight and complexity makes it sufficiently advantageous. Rail travel needs to be at the forefront of "green" transportation and to show it.
O L Leigh
I like the idea of electric vehicles, but there are a few major problems with battery-powered cars. They work fine for short journeys, especially with a lot of stops so that they can take advantage of regenerative braking (that's one reason why milk floats tend to use batteries). Excellent for town cars, doing the school run or the weekly shop, but a nightmare if you live in the country. Short hops to the nearest town are OK, possibly, but lack of high-capacity charging facilities mean a major recharge every night. I don't use cars much, but often tend to make very long runs, and that's where the battery falls down. There's no cantenary over trunk roads, and 200+ miles on batteries (especially towing a boat) is just about it. That then means a series of recharges, thus holding things up. You can't carry everything onto a train, nor can a train get you to difficult places, where the wildlife is. Fuel cells would have the capacity to do it, and H2 does not bleed off as quickly as batteries lose their charge.
However, running electric vehicles directly off the grid would work very well. Trams and trolleybuses are extremely efficient, and trolleytrucks would probably do very well on major roads (special electrified lanes on motorways for instance) and in town, but would require massive battery backups if they had to deliver away from the wires. Hydrogen might be an answer to the range issue, and it does give something that can replace diesel vehicles in some cases. If really necessary, railways can go back to steam if electrification is impossible, buses and lorries can convert to direct electric traction, and agriculture can use horses. The major problem is for private vehicles in the country, which people cannot do without.
There is an added benefit to hydrogen, deuterium. Electrolysis of seawater is the ideal way to extract Du from heavy water (about 1% of seawater) to provide fuel for fusion reactors. If we ever get fusion working, we will need lots and lots of fuel to make electricity, some of which will be fed to the electrolysis plants. That produces
lots of H2 and O2.
However, we are speculating about events in the 2040s, probably in the wrong forum. I doubt we will ever see H2-fuelled trains, even steam would be more efficient, but we might just see fusion power providing the electricity that the successors of Eurostar and the Class 92 run on.
