Search Results: "sweeks"

16 March 2007

Russell Coker: worse than fossil fuel?

I just read an interesting blog post from December 2005 about the environmental impact of bio-fuels. It makes some really good points that should be studied by everyone who is interested in protecting the environment.

However this doesn't mean that bio-fuels are inherently bad, just that some methods of production are bad.

The blog claims that reusing oil that had been used for frying would cover 1/380 of the fuel used for road transport in the UK. There are some technologies that have been recently invented to process farm and industrial waste into oil, some of which are already in production in the US. The volume of farm waste (and equivalent waste from restaurants) would significantly exceed the frying oil from restaurants and converting waste plastic into fuel would add even more. I'm sure that these sources of fuel from waste would add up to at least 1% of the current transport fuel use.

A better train system has the potential to halve the use of fuel for transport (or better), when living in Europe I never considered owning a car, the trains were so good and the car parking was so bad that it wasn't worth doing. A combination of less cars and the cars being driven less would significantly reduce fuel use.

Hybrid vehicles and vehicles with smaller and more efficient engines could halve the use of fuel again (or better). Diesel hybrid cars that are currently being tested use as little as 1/4 the fuel of current petrol cars. Add further technological improvements such as the six-stroke engine and we could be looking at something better than four times the current fuel economy of cars.

I don't think it's unreasonable to assume that a combination of a good public transport infrastructure, fuel efficient vehicles, and government incentives for using both could reduce the transport use of fuel by a factor of 8. This would mean that fuel produced from restaurant, farm, and plastic waste (which I conservatively estimate at four times the volume of used frying oil) could account for more than 8% of the fuel supplies. The EU wants to have 5.75% of fuel oil to come from renewable sources, it seems to me that this is possible without importing any bio-Diesel from developing countries!

Electric cars could of course significantly decrease the use of fuel oil too. A Prius+ (Prius modified to take mains power) would be an ideal vehicle for me. I rarely make long journeys and rarely make multiple journeys in one day so I could use mains power most of the time. I estimate that with a Prius+ I would use no more than two tanks of petrol a year.

Then of course there's the issue of market protection. It seems that every first-world country has a farming lobby that convinces the government to pay them to produce more crops than they can sell at market rate. Instead of subsidising food that is sold to other countries such government money could go towards subsidising development of bio-fuels. The US subsidy of corn production is a classic example of this, corn syrup can be easily fermented and distilled to make fuel - much better than eating the nasty stuff!

17 October 2006

Russell Coker: more on clean energy

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.

23 February 2006

Brett Parker: Soooo...

Here goes a quick summary of this week... Monday + Tuesday, looking through lots of bash and perl, trying to find a nice way to fix it, still not found. Lots of other things needing doing, mostly a busy start to the week. Wednesday - good start to the day, stuff started to make sense. Then I get The News at about 11:00 (I hadn't been keeping up with LJ, and when I was looking at it, it turned out I wasn't logged in, so when I got the news I nipped over to LJ and logged in and felt sad, lots). Lost half the rest of the day thinking about it. Managed to get to a state where I was alright again, stopped reading LJ for the afternoon. Came home. Slept. Today - mostly productive, still not over the shock. Maybe I can get some coherent words and thoughts tomorrow? Must get back in to doing my NM - sorry Myon, I've been distracted for too long! I'll get back at it, erm, soon! Tomorrow, well, it's Friday - a whole weekend to come and think about things.