One new technology for saving fuel in cars is the 6 stroke engine. This is an engine that has two power strokes for every intake of fuel. The first power stroke is from the fuel burning, the second is from water being injected into the cylinder and boiling rapidly using steam for power. A significant amount of the weight of a car or truck engine is the cooling system. With water being injected into the cylinder after every burn the engine will require no other cooling, this can mean a weight reduction of up to 500KG for a truck engine! It is claimed that this technique can “improve a typical engine’s fuel consumption by 40 percent”. Note that this technique could be combined with the technology in a Prius for even greater efficiency.

Simon Richter wrote an interesting response to my blog about clean energy. I’m guessing that the part of Germany he’s from is similar in some ways to Amsterdam (where I used to live).

In Amsterdam tiny cars are used a lot more than they have been in most places. There is the Smart Car but there is also a tiny car that can only seat one person (I’ll update this entry with a link if someone provides me one). The tiny car appears to weigh ~200Kg, has a maximum speed of 30Km/h, and is narrow enough to fit in bike lanes. Such cars will take little petrol and can be used for shopping. The short-distance car idea is being used by many people already in northern Europe.

Simon suggests having a standard baggage container that fits in all cars. I don’t think that would work as there are many different design factors (parking space, cargo capacity, and aerodynamics) which force designers to choose different shapes.

I think that a better idea would be a standard baggage trailer that could be towed by any small car. It should not be difficult to design a trailer that can be safely towed at 30KM/h behind a tiny car. The supermarkets could rent such trailers to shoppers for a nominal fee. Then most shopping trips could use the cargo capacity of the tiny car, but when buying supplies for a party you could rent a trailer from the supermarket.

Another option is having shops deliver goods to you. I have observed an increasing number of people doing this at my local supermarket. Of course you would still need to take ice-cream home yourself and maybe milk and meat too.

Electric scooters are also a good option for travel. Unfortunately in Australia there are few good options for securing them at the moment. As an electric scooter is light enough to be carried it needs to be chained to something secure. In the Netherlands this wouldn’t be a problem as the bicycle infrastructure includes plenty of bike racks to which you can chain your bike, scooter, etc. Of course the Netherlands is entirely flat so there’s no need for an electric scooter. Melbourne has a lot more hills and most people aren’t fit enough to ride a bike so scooters are needed to replace cars.

Regarding depersonalised cars. That would require a significant social change as currently cars are extremely personalised. One thing that I had been thinking about is the idea of sharing cars with neighbors. For example if you have an apartment building and there are a few people you trust then you could share a tiny car for going shopping. Sharing a car used for driving to work or for entertainment would not work well as the car would spend most of it’s time in use (or at least parked somewhere away from home). Sharing a car that’s used for small journeys would be much easier as such a vehicle would spend most of it’s time at home.

In Australia most families have two cars. One is used a lot (spends maybe 70 hours a week away from home) and the other is used much less (maybe 10 hours a week). Instead of owning two cars it would be possible for families to own one car and share another.

Regarding the Pebble Bed Reactor, could the people who advocate it please read the Wikipedia article. The limiting factor is not thermal expansion (solids do not expand nearly enough) but the Doppler effect (fast neutrons are not as effective at triggering fission). But in spite of that issue, let’s not consider an untested new reactor design to be the savior of nuclear energy. I think that most people who read my blog have a science or engineering background and know from experience that new technologies often don’t work too well in the first version. When a new CPU has a bug it’s usually not a big deal. When a new OS or application has many bugs it’s often expected (expecially when the OS or application comes from a monopolist). But if a new design for a nuclear reactor turns out to have a bug then it will be a more serious issue.

There are many people claiming that nuclear power will solve all the ills of the world. However this does not seem to be possible. Firstly you have to consider the hidden costs of nuclear power such as deaths from the mining industry (ingesting uranium ore is a really bad thing) and the difficulty in disposing of radioactive waste. But rather than concentrating on the bad aspects of nuclear power (which are well documented) I will concentrate on some of the viable alternatives.

Wind power is a really good option, particularly for countries such as Australia that have a low population density and a large land area. The Chinese government is investing heavily in wind power, I think it’s safe to assume that it’s not because they are great environmentalists but because they simply need more energy than they can get from other sources and that they have strategic reasons for not wanting to rely on Australian coal and uranium or Arabian oil. Most energy sources have some drawbacks, but wind power has no side effects and isn’t going to kill birds either (birds have evolved the ability to detect and avoid predatory birds, they can easily avoid large fixed objects such as fans from wind farms).

Two other good options are wave and tidal power. These are better than river based hydro-electricity because there is no need to create dams that remove forests. Wave and tidal power are both very predictable which is an advantage when compared to wind power which is less predictable. One solution to the unpredictability of wind power is to couple it with a river based hydro-electric system which can provide electricity when there is less wind. A hydro-electric system to compensate for days that are less windy would need a much smaller dam than one that is designed to provide the main power source.

The next issue is how to power vehicles (on air, land, and sea). Advocates of nuclear power often talk about hydrogen powered cars. However while hydrogen has a good ratio of energy to weight it is not very dense, so the energy density for volume is much less than petrol. Combining Prius technology with
hydrogen in an internal combustion engine still won’t give the distance per tank of fuel as petrol does. Hydrogen with fuel cells in an all electric vehicle might allow you to drive the same distance as a non-hybrid car on petrol, but probably won’t compare to the range of a hybrid Diesel vehicle.

Bio-Diesel is a good option for fuelling cars. Diesel engines give greater efficiency than Otto cycle (the most common car engine) or Atkinson cycle (as used in the Prius) engines. Not only is bio-Diesel renewable but it also produces exhaust that is less toxic than that which is produced from fossil fuels. See the VeggieVan site for more details on bio-Diesel. The toxic fossil fuels are linked to health problems in airline hostesses, AFAIK there has been no research on the impact of car exhaust on pedestrians.

One thing to note about bie-Diesel is that you can do it right now. According to a British TV documentary all you have to do is filter oil that was used for frying food (they used oil from a Mexican restaurant) and mix it with a small amount of ethanol and it’s ready to use in your car. As restaurants currently have to pay to dispose of old frying oil this should be good for everyone!

Bio-Diesel could work for powering planes, there is already research in progress on this issue, but there are problems related to the viscosity of bio-Diesel at low temperatures. Maybe a blend of bio-Diesel and bio-Ethanol would work. Ethanol freezes at -114.3C and should lower the freeze temperature of bio-Diesel.

Bio-Diesel would of course work really well for ships. Supplying the amount of fuel that current ships need would be difficult. Some analysis shows that the deck area of a ship can collect enough sunlight to supply ~10% of the power needs of the ship. The Orcelle is a design for a totally clean ship that runs on solar, wind, and wave power. However with the proposed design the solar panels will not be angled effectively for collecting sunlight as they will be on sails. I think that there is a lot of potential in having a design based around sails, wave and solar power for generating electricity, and also a Diesel engine running on bio-Diesel fuel for supplying extra power when required (EG when sailing at night in calm weather). Building a ship that uses only wind, solar, and wave power would probably be significantly more expensive than the current Diesel design. Building a ship that uses 10% Diesel and 90% wind, solar, and wave power might be a lot cheaper.

There are lots of ways of producing the energy we need to maintain our current standard of living. If our government was to spend as much money researching them as it does protecting petroleum reserves then the problem would be solved.