By Fester
Diesel is much more expensive than regular unleaded which is a change from traditional patterns. It is also a high demand product as the refineries are making more money on their diesel products than on their regular gasoline products. Some of this is due to a shift in the composition of the crude oil inputs as heavier assays require more effort to turn crude oil into diesel at the refineries, but a significant portion of the price increase is due to increased demand.
A portion of this demand is coming from a shift in transportation fuels towards diesel and away from gasoline. This is noticable in the car market as well as in the train market. However most of the increased demand is the traditional story of increased wealth in China and India as more areas are electrifying by local generators. Kat, our researcher, also noted that diesel generators are common power supply systems in Iraq and other unstable/violent areas.
I am interested in the nature of resiliency that diesel generators posses and whether or not this is an actual feature or an illusion of a feature. Most of the diesel generators are being installed in areas where there is minimal reliable connections to a centralized or regionalized power grid. This is either due to large scale system disruption/sabotage enhanced by localized fragmentation such as in Iraq, or the more common story of rural areas in India and China becoming wealthy enough to afford power but due to the combination of burgeoning urban power demand and high costs of connecting to pre-existing and not too reliable grids, localized prodution is the better alternative.
However in almost all scenarios, the localized production is at the tail end of a several thousand mile supply chain that is fairly brittle and volatile. So is this really resilient when small communities have some interconnectedness with the larger social mileau but also possess point power generation if that power generation is not sustainable from local resources? Or is this a movement of substitution of irresiliency as localized complexity and energy needs have jumped up while localized production has decreased?
I would say diesel generators are resilient up to a point based on type and duration. As a back-up or bridge, they allow you to survive temporary outages or failures in connectivity to the outside.
ReplyDeleteOn the other hand, if you come to depend upon the generator as your primary power source, then the fuel supply becomes a single failure point, which is non-resilient.
Resiliency is the right word. Diesel generators allow energy storage near the end user. That absorbs transients in the system. If the diesel supply goes down for a couple of days, the end user doesn't feel it.
ReplyDeleteIt doesn't protect the end user from long term system failure - but not much does, shy of a survivalist living on a farm, willing to use corn cobs for toilet paper.
You folks have not been around many diesel engines, have you?
ReplyDelete1) diesel is less susceptible to corrosion during storage
2) diesel engines are more robust
a) no spark plugs
b) no carburetor
c) no points
You are trying to find complex answers to a simple question. Why are there so many diesel generators in remote places or trouble spots? Paul A'Barge is dead right. You need to get out and talk to someone who uses diesels. Any truck driver or farmer can tell you all you need to know.
ReplyDeleteHere we go:
Diesel fuel is a better fuel for the purpose than gasoline. Its flash point (the temp at which it burns) is higher than gasoline. Gasoline is more volatile (i.e. gives off more fumes) and the vapors explode readily. Diesel stinks but it doesn't explode. Which do you want to haul over a mountain trail in metal cans with pack animals? Also, diesel has about a third more heat energy per gallon than gasoline. And, gasoline deteriorates with time. After about six months it can become smelly and oily and won't burn well in a gasoline engine. Diesel fuel takes longer to deteriorate.
Now for the engines. A typical Briggs & Stratton or Tecumseh gasoline lawnmower (or generator) engine has a mean TBO (time between overhauls) of about 500 - 600 hours. That simply means they don't last long. Five hundred hours of generator time is only about three weeks. Then the engine is worn out. Hondas can last up to 5000 hours between overhauls, by the way.
Diesel engines have a TBO of between 10,000 and 30,000 hours. Why? Because they are made much heavier and stouter to handle the higher pressures that diesel causes when it explodes inside an engine. Also, as Paul aluded to, diesels are much simpler than gas engines. There aren't as many parts to fail.
Other reasons you want a diesel as the engine on your genset: Diesels use very little fuel under no-load or light-load. Repair parts can be fabricated locally by any competent foundry. If your diesel storage tank gets hit by a stray round (translation: a bullet hits it) the tank leaks diesel. If a gasoline tank takes a bullet, it explodes. Which do you want next to your house in a town that doesn't have a fire department?
As to the notion of resiliency, remember that PEOPLE are resilient. And people around the world choose diesel engines because of the dependability of diesel. I live in a major city and use a generator 2 or 3 times a year because of power outages after storms. Being connected to the grid is great but it isn't a panacea.
Hope this helps.
For what it's worth, you can also burn just about anything in a diesel engine. Paint thinner, used crankcase oil, straight vegetable oil, lamp oil.
Been a transportation diesel enthusiast for almost 20 years now, ever since my first car, a 1979 diesel Rabbit that lasted 479k miles. Engine was still ticking away, but first and second gear melted.
ReplyDeleteAside from being a simple light oil as opposed to a corrosive distilate, diesel produces top torque at a much lower RPM than a gasser. That means reduced revolutions per mile which means a longer life as less revolutions means less wear. Compression ignition also demands a much more robust contruction, as previous commenters have pointed out. Add in a much higher BTU content and you have an ideal remote power source.
Algae is the biggest danger in diesel storage. It can alter the chemical make-up of the oil in extreme cases, but water usually simply sinks to the bottom of the container and can be heated off if needed. Simple field filtration methods can usually bring dirty diesel back to life. for some reason, people in the US have many unfounded fears of diesel. Too bad.
Fantastic writing: Will come back again soon=)
ReplyDelete