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BMW has released a new prototype hydrogen powered car. The bmwworld.com web page about it claims the cruising range is 190 miles. Added to the 400-mile range of the normal fuel tank, the 745h can go 600 miles between fill-ups. The first issue is that 10 miles are not accounted for (maybe it finishes the 190 miles of hydrogen power at the top of a hill). But more seriously the hydrogen needed to drive for 190 miles would take as much space as petrol needed to drive for 646 miles (hydrogen needs 3.4* the volume to store an equivalent amount of energy). I wonder if that BMW has any space left in the boot/trunk?
Now we have some green bloggers praising BMW. An internal combustion engine that burns hydrogen will not give no emissions other than water vapour, it will produce some nitrogen oxides. The processes to produce hydrogen for fuel all consume unreasonable amounts of energy (more than is required to charge a plug-in hybrid).
BMW demonstrates their level of interest by giving the cars to some celebrities. This gets some PR but no analysis of the performance. They also introduce the prototype based on one of the most expensive models (the 745) which you almost never see on the roads. If they produced a 318 or 520 that ran on hydrogen it would demonstrate some level of interest in getting this working for the mass market.
If BMW wanted to make their cars more environmentally friendly they would start by adopting some of the technology from the Prius. Rumour has it that part of Toyota’s plan to make money from Prius development is in licensing the technology that they patent. A couple of years ago I test drove a BMW 316 and a Prius. The Prius was very quiet and gave a smooth ride (you might call these luxury features), and also gave decent performance (it’s widely regarded that luxury cars should perform well – pity the BMW 316 is a slug).
In Australia the concept of “badge engineering” of cars is well established. When government subsidies favoured large manufacturing runs the Ford Laser and Mazda 323 were essentially the same car. Maybe BMW could adopt this concept and sell a re-badged Prius i-tech with a few extra luxury features as a BMW 4 series (it’s a much better car than the 3 series BMW).
Finally bmwworld.com has an amusing FAQ about hydrogen power, here are some of the mistakes that they make:
- They say “About 45 billion kilograms (50 million tons) [of hydrogen] is produced every year—enough hydrogen to fuel 250 million fuel cell cars“, but only if the average fuel-cell car uses 180Kg of fuel per year. According to Wikipedia hydrogen has slightly more than 3* the energy density per mass than petrol, so 180Kg of fuel would be equivalent to 540L of petrol per year. The Australian Bureau of Statistics states that in 1996 the average annual distance travelled by car (it’s not clear whether this is per car or per person) was 14,600Km while among the countries listed the lowest was Japan with 10,130. When efficiently using hydrogen in a Prius (that is quoted as using 5.4L of petrol per 100Km) you might expect that 540/5.4*100=10,000Km could be travelled on the 180Kg of hydrogen. So the FAQ claim that 250M cars could be powered by the current hydrogen production would only apply if the cars are of Prius efficiency and driven the typical distances of Japanese drivers, or the cars were 46% more efficient than the Prius and driven in the Australian manner. Of course in the US things are even worse with 17,862Km being the average distance driven which means that their hypothetical fuel-cell car would need to be 78% more efficient than a Prius.
- They state that “the majority of merchant hydrogen is produced by a process called steam methane reforming“. Why not just run cars on methane then? Anything that burns can be used to fuel cars, and methane has a much higher boiling point than hydrogen so it would be easier to store and transport (see the Wikipedia page on methane).
- In regard to hydrogen production they say “about 95% of the total global hydrogen production is captive meaning it is used at the site where it is produced“, that is of course because it’s difficult and expensive to transport hydrogen.
- The final amusing fact is that it is noted that most hydrogen comes from fossil-fuels. What problem are they trying to solve here? Hydrogen isn’t going to help the environment if it comes from fossil fuels, it will be more expensive than other fuels. Apart from getting government grant money for BMW it doesn’t seem to do any good.
I just noticed that my post about LED Headlights in an Audi Sports Car was linked from audi.host4blogs.com. Strangely they took some of the words from my post, added some other apparently random words to make it look like a response, and then linked to my post.
Having summaries of my blog posts appear on splogs is nothing new. I don’t have any objection to it normally as summaries will in a small way promote my blog as long as they are intelligible. The host4blogs.com site has a couple of other car blogs that link to each other with content of the same quality.
I guess I can’t file a DMCA take-down request as the text is not a summary of mine. I hope that Google will start taking action against the sploggers soon.
One of the most important issues for a commodity fuel for vehicles is that it be convenient and safe to transport. For quite a while LP Gas has been available as a cheaper car fuel. Even with increasing petrol prices it’s acceptance is well below 100% due to extra expense in storing the fuel (high pressure and more insulation are required), the more expensive technology in the engine to heat the fuel before injecting it into the engine, and the extreme difficulty in creating something as convenient as a Jerry Can for transporting LPG.
LPG is mostly comprised of Propane and Butane. Propane has the lower boiling point of -42.09C. Hydrogen however has a boiling point of -252.87C and therefore is much more difficult to store and transport.
The next problem with hydrogen as a fuel is that it has a very low density. The energy density per volume of liquid hydrogen is 10.1MJ/L while the energy density of petrol/gasoline is 34.6MJ/L. Not only is liquid hydrogen difficult to transport but the vessels you transport it in need to be 3.4 times the size! Having a 3.4x larger fuel tank in a car may not be a huge obstacle, but then there is the issue of trucks used to transport it to fuel stations which are already at maximum size so the truck fleet will need to be 3.4x larger with more people driving them etc.
Once these problems are solved there are a variety of safety issues. Hydrogen burns with an almost invisible flame, sustains a fire when at a concentration of between 4% and 75% of the air and ignites at a low temperature. For an explosion you need a concentration of between 18.3% and 59%. I won’t risk promoting foolish behaviour by describing details, but when younger I have performed experiments with ethanol and witnessed experiments with petrol that demonstrate that they are both far less dangerous. Page 22 of this document by the US Bureau of Transportation and Statistics gives more information about the fire risks posed by hydrogen fuel. Page 35 of the same document describes fuel cells as being 45% efficient and an internal combustion engine for methane gas as being 30% efficient thus giving overall efficiencies of 33% and 29.5% respectively. Of course using an Atkinson Cycle engine will give a significant efficiency benefit over an Otto Cycle engine and outweigh this. Also it should be noted that fuel cells tend to require expensive materials such as Platinum in their manufacture.
Hydrogen is promoted by clean-coal advocates (not that any form of coal power is clean) and the nuclear industry (electrolysis is one way of using a huge amount of electricity). But there are many better options for powering cars that are available right now at minimal cost, these include bio-Diesel, ethanol, and plug-in hybrid or electric vehicles.
There is a lot of career advice related to writing CVs in books and floating around the net. Unfortunately almost all of it is tailored to permanent positions.
Some advice that I have seen includes researching the company you are applying for and emphasising your experience in related fields. This probably makes some sense if you have targetted a major company to be your employer for the rest of your life. But if you are after contract work (which incidentally tends to pay better than permanent positions) then it’s not going to work. About half the time when applying for contract work you won’t know the name of the company that is receiving your CV until after they have decided whether to grant you an interview.
Contractors therefore need to write their CVs to have broad appeal (emphasising common technologies such as C programming and skills such as debugging), and to appeal to a recruiting agent.
Some people recommend writing your CV in MS-Word to support agencies and potential employers who are not competent enough to open other file formats (such as PDF and HTML). I strongly disagree with this advice, most contract positions are advertised by multiple recruiting agencies and it would be best for you to be represented by the most competent agency. Therefore having an agency staffed by incompetent people not represent you because they can’t figure out how to read a HTML or PDF file is a good thing! The same applies for employers, while applying for the best paying contracts will often result in some strange and unpleasant working conditions having a manager who can’t open a PDF or HTML file is likely to result in something that is unusually bad – run away!
Recruiting agents will often give specific requirements for a CV. Sometimes these requirements are a little odd (such as demanding that references to C programming be removed from a CV when applying for a Unix sys-admin job), but being merely a little odd is no reason to boycot the agency. To solve this I wrote my CV in M4 macros to generate HTML code. When I wanted to apply for a position I would just type make to compile the M4 source into five or more different CVs. Sometimes a recruiting agent would request two versions when applying for one position, it’s a strange request but when five versions were compiled in one pass it was easy to satisfy it. If I liked PDF I could have written M4 macros that generate TeX and have the make process convert TeX to PS and then PS to PDF.
Unfortunately I can’t share any macros because the code was not of particularly high quality (which is a little ironic) and because it’s tightly tied in to my CV. The best piece of advice that I can give to anyone trying this is to get columns sorted out as the first issue. If you want to have some lists of programming languages, lists of OSs, and lists of hardware, etc in your CV then it usually works best to have two columns in the page. If the largest list is removed then the other lists need to be shuffled around to get the column lengths to match. Doing this in HTML required some ugly M4 macros. There probably is a better way of doing this in TeX (but I’m really not good at TeX and can’t give advice about it).
James has some interesting advice about writing CVs. I think that his most useful points are:
- Use file names based on your name so that agents can find your CV in the directory full of CVs
- Include complete contact details. One thing he doesn’t mention is that you should buy a mobile phone for the purpose of getting a job even if you don’t want one for any other reason. A 5% difference in pay for a year’s work would cover the cost of many mobile phones and the difference between a good job and a bad one is likely to be more than 5%. If you are afraid of brain cancer then don’t worry, if you only spend a few minutes a month talking to recruiting agents then you are at no risk.
- Don’t start a sentence in the career history section with the word worked – everything in that section will be related to where you worked in the past. It seems obvious in retrospect but I realised that I have made this mistake on my CV.
Ben Fowler blogs about the issues related to running IRC as root. Google searches for (irc client exploit) and (irc client “buffer overflow”) give a number of interesting web pages. Many of the exploits require the user to perform an action that’s slightly unusual, but why take a chance?
The advice to not run as root while generally sensible (run everything with minimum privileges as much as possible) is IMHO not very useful in recent times (and probably was never very useful). Generally when a user is worried about system compromise they are not worried about attackers having direct hardware access, the ability to corrupt system files, etc. They are worried that the attacker might read their email and access other personal files.
Therefore the instruction should be “don’t run IRC as root or as any account that has access to data which is important to you“. It’s not difficult to start an X-term that runs “exec su – ircuser irc” or “ssh -t ircuser@localhost irc“. Note that the -t option is required for ssh to make it allocate a pty even when receiving a command to run. Note also that in the case of su you need the exec option so that if the irc client is compromised and tries to perform a ioctl(0, TIOCSTI… based attack then it won’t succeed.
In any of these methods make sure that X access is not granted. Until we get Security Enhanced X working in a viable manner any process that can display an X window on your screen can own you totally. There are of course relatively safe ways of doing X, I have previously documented how to configure the Xephyr X server (replacement for Xnest) to allow a process with a different security context to safely display a graphical window on your desktop.
Generally I recommend not using a graphical X client on an untrusted network (IE anything other than an Intranet IRC server). I prefer to do my IRC in an account that’s not even on a machine that I care about and have it run screen so I can disconnect and re-connect from anywhere in the world.
When I first got SE Linux in Debian to be useful (when I could boot and run all programs without problem) I logged on to some IRC channels related to Debian with the security context of root:user_r:user_t. I admit that my actions in this regard could possibly be described as trolling, but I wanted to demonstrate what SE Linux can do. Unfortunately of the many people who told me off for logging in to IRC as root, none of them wanted to hear an explanation of why user_r is safe in this regard. I expect that most of them were running their IRC client in the same Unix account that was used for their email etc (and probably most of them had GPG keys accessible from such an account).
Sigh, it’s so easy to run IRC as a different user – in fact it’s probably the easiest of all network client programs to run in such a manner. There’s no reason not to.
The Australian has a new Environment writer named Matthew Warren who has a history of doing PR work for the coal industry. This has the potential for insightful articles based on knowledge of what the industry is doing or for PR work for the coal industry masquerading as journalism. Unfortunately it seems like the latter is what we are getting.
Matthew’s latest effort is an article claiming a $6.5 billion cost to home-owners because of an “effective ban” on electric hot water systems that Labor might impose. Unfortunately he doesn’t clearly state what an effective ban is, but does note that apartments are exempt.
The specific claim that is used as the basis for the article is that solar hot-water systems cost $2,800 more than electric systems, and that after the solar hot-water rebate ($1,000) the additional cost would be $650,000,000 per annum, and that a period of 10 years would be required to replace all hot-water systems thus giving a cost of $6,500,000,000. So I presume that he expects that there would be 650,000,000/1,800 hot water systems installed per year which would be about 361,111.
According to the Australian Bureau of Statistics there were 6,744,800 households in Australia in 2003. Matthew’s article states that about 40% of homes can have gas hot-water systems fitted that comply with the proposed new regulations, given that and the exemption for apartment buildings let’s assume for the sake of discussion that 50% of homes would require a solar hot-water system. Assuming that each household has a separate hot-water system that means that for these claims to hole we need an average expected lifetime for a hot water system of 6,744,800/2/361,111 = about 9.3 years. If the currently installed hot-water systems are expected to be replaced in 9.3 years then we can expect that hot water systems tend to survive for an average of about 18.6 years. I wonder if that number is correct (some google searching didn’t turn up an answer). One of the disadvantages of old-fashioned media is that they tend not to include calculations or cite sources adequately so we can’t easily verify or disprove their claims, I wonder if this is deliberate…
Matthew admits that using a solar hot water system can be expected to save households $300 per annum in electricity expenses, I presume that this is based on current energy prices and that the savings can therefore be expected to increase as energy prices increase (we have a lack of water which is increasing the cost of producing electricity from coal).
Let’s assume for the sake of discussion that the typical home-owner has a mortgage, the Commonwealth Bank is currently advertising mortgages with a rate of just over 8%, the way things work is that there are various criteria for getting a discount rate which most borrowers can meet so the result will be slightly below 8%. If a solar hot water system costs $1,800 extra to install and the money comes from a mortgage then every year it will cost the home owner about 8% of $1,800 which is about $144 (a saving of $156 per annum). If the solar hot water system saves the home owner $300 per annum then at any interest rate below 300/1800 (16.66%) they will make money.
If there was no government subsidy and the entire $2,800 extra was paid by the home owner then at 8% interest it will cost $224 per annum (a saving of $76 per annum) and the interest rate would need to increase to 300/2800 = 10.7% to make it break even.
So for solar hot water to not save the home-owner money we need to have a significant increase in interest rates (which incidentally would bankrupt many home owners), AND to have electricity prices remain the same (which would require even more of our tax money to be spent on supporting the coal industry).
Finally Matthew complains that the solar hot-water rebate could cost the government $4 billion over the course of the scheme (the next 10 years). This sounds like a lot of money until you think about the 9 billion dollars a year that the government spends on subsidies for the coal, oil, and gas industries! On the current course the government would spend 90 billion dollars of our tax money subsidising polluting industries that cause climate change, but Matthew opposes spending 4 billion subsidising technology that prevents pollution and reduces climate change.
I was recently talking to a client about the lack of guidelines for acceptable personal use of office resources in his company. He rejected the suggestion that he provide any real rules or guidelines (apart from some old rules that most employees were not aware of and of which there was no procedure to remind them to periodically read). He said that he only wanted to hire motivated people who wanted to work, and that people who need rules should work elsewhere.
The results of his approach seem reasonable, everyone who works for him works really hard. In return his attitudes towards employees are more relaxed than most employers, among other things he is very supportive of employees who desire career opportunities greater than his company can offer.
I have been wondering whether rules alone can make people lose interest in working, or whether it’s the type of person who doesn’t want to impose rules that inspires hard work.
My experience is that when working for people who have a rule-free environment I tend tend to work really hard, and that when working for companies that have lots of rules I find it difficult enough to get out of bed in the morning – let alone become motivated to do any work.
I am interested to see comments from other people, both workers and managers. Is my experience common in this regard?
Dell just sent me a letter advertising their new Vostro line “especially for small business“. They say “we listened, then we listened some more” and explain that it’s based on feedback from people in small companies. The problem (which should be familiar to everyone who has ever done any consulting work) is that people don’t ask for what they need! Ask someone what they want in a computer system and the first thing that they will ask for is a fast CPU and a low price, the colour of the box will probably be higher on their priority list than the option of a backup.
Dell have proved this by advertising their small business machines by advertising cheap desktop machines for small business use.
Here is a list of the features that I consider essential in small business systems (based on my experience working for dozens of small companies):
Reliable operation. Using a relatively inexpensive machine as both a desktop machine and a server for the company network is very common in companies with less than 10 people. The Dell PowerEdge Tower systems are reasonably cheap (as little as $800AU – $100 more than a low-end Vostro in the base configuration, although the Vostro includes a bundled monitor). The PowerEdge machines have ECC RAM as a standard feature (avoids data loss due to memory errors) and can be delivered with hardware RAID support (SATA-2 or SAS) and a variety of backup options. A low-end tower PowerEdge server with 250G of hardware SATA RAID-1, a 160G removable disk for backup, and an extra gigabit-ethernet port costs $2015. Such a machine would do really well as a server for a small company while also being quite good as a desk-side workstation (the cooling fans would probably be louder than on most workstations but the money saved would be worth-while for most small businesses). If Dell was to promote PowerEdge tower machines (maybe under the label “Vostro Servers”) it would be good for customers and should be profitable for them.
The next thing that Dell should consider is a laptop with ECC RAM. Many small businesses start out as a sole trader with a laptop. Data loss on such a machine would be catastrophic. At the design stage ECC RAM would not be difficult to add – if there was a company that produced such RAM (I expect that Dell could purchase enough volume to drive the creation of new memory modules).
Another laptop issue is the reliability of mass storage. Laptops tend to get dropped and hard drives tend to break when dropped. Lenovo sells a “ThinkPad Serial ATA Hard Drive Bay Adapter” which allows two hard drives in a Thinkpad which could be used for RAID-1 (if you don’t want a built-in DVD drive). I chose to use regular backups instead of buying the extra hardware for RAID-1 but it would be good if other companies offered such options – especially when promoting their products to small businesses (who often don’t do regular backups). Even Lenovo could improve things in regard to their potential RAID-1 support in Thinkpads by promoting this feature (instead of just having the hardware listed as an optional extra with no mention of why you would want it) and offering a default install with RAID-1. Better still would be hot-swap RAID-1 in a laptop (which would be quite easy to do if the expansion bay was changed to use USB as it’s method of connection). Of course RAID-1 only covers you in the case where the drop is only enough to destroy one disk or if it causes partial damage to both disks but doesn’t destroy the same section of data on both disks.
The next big thing for laptops will be flash storage. One of the major advantages of flash is that it’s almost impossible to destroy it by dropping it. I would rather have my important data on a flash storage than a hard drive (it also saves electricity and therefore makes the battery last longer). The option of having flash as the primary storage device and a hard drive for files that are larger and less important would be useful to most small businesses. Of course hardly any small business owners will ask for this, they will probably ask for a machine that has a fast CPU.
Sometimes when developing a product you have to design something with the features that customers need and get the sales and marketting people to convince the customer of the benefits of the features. Even though the number of people who understand the technology and will jump at the opportunity to buy good things (such as me) is rather small, the number of people who can understand once it’s explained to them is quite significant. I’m sure that if Dell released a new line of computers with the slogan “reliable machines that don’t lose your data” instead of “good-looking new machines” then they would get some interest.
After writing this post but before publication time I happened to be speaking to the owner of a small business on the topic of choice of computers for a company such as his. He seemed convinced of the benefits of a better machine to replace his current desktop PC that is running as a server (it’s yet to be seen whether he considers the benefit to be worth the cost).
I wonder if Matt Domsch reads my blog…
A frequent criticism of solar power is that the sun only shines brightly for part of the day, and that many of the times when there is significant electrical load (EG when people get home from work in winter) the sun light will be weak. One interesting solution to this problem is to store the solar power by splitting ammonia into nitrogen and hydrogen gases, storing them separately, and then reacting them to produce super-heated steam for power generation at any time that power is needed. The technology is based on three decades of research at ANU and the Federal government has allocated $7,400,000 for building a power station near Whyalla in South Australia.
The down-side to this is that it needs water for the steam part of the electricity generation process which is a minor problem as we are having water shortages in most parts of Australia. But the up-side is that the process of combining nitrogen and hydrogen to produce heat should be something that can be turned on rapidly. So it seems that there is potential for having a wind power plant designed to satisfy all the power requirements on windy days and store hydrogen and nitrogen for times when there the combination of sunlight and wind is not adequate to satisfy the power requirements.
Previous plans for the maximum possible use of renewable energy in producing electricity have included gas fired power plants for times when wind and solar power can’t meet the demand. It seems that with technology such as this one it will be practical to have all electricity produced from renewable sources of energy.
Due to climate change and population increases we are having increasing problems with the water supply in Australia. Peter Lieverdink suggests that we have more options for water supply including treated sewage similar to the Netherlands here he grew up. However I believe that in Australia we already do what he proposes (put treated sewage in rivers and then use the same rivers for the water supply). It’s just removing the middle step (of having the treated sewage in a river) that is controversial.
I recently examined a water bill for my house. Among other things it said that my water use was slightly above the average for houses that use water efficiently and significantly below the average for typical water use. The funny thing was that most of the expenses on the bill were not actually related to the amount of water used. My bill for a quarter was $54 service charges for sewerage and water (of which $39 was sewerage), $30 for sewage disposal, $26 for water, and $14 for drainage. So the cost of disposing of sewage was greater than the cost of getting fresh water and the sewerage service charge was the largest single item on the bill.
Australia supposedly has a capitalist economic system in place (except for the communist policies related to farming and the protection of some industries such as car manufacture and coal mining). Surely the right thing to do is to make water expensive enough that people have a financial incentive to conserve it!
The first thing that should be done is to make the majority of the value of a water bill received by a typical household be determined by the amount of water used. This could be achieved by reducing the fixed components of the bill to something small (EG $20 per quarter instead of $98 for me) and then increasing the cost per kilo-litre (EG from $0.85 to $2.50). The end result would be that people who use average amounts of water would pay about the same amount as they do now and people who use less than the average amount would get smaller bills, while government revenue would remain the same.
The next thing to do is to have different tarriffs for different quantities of water used. The first 50L per day could be free (water for drinking and cooking is a right), between 50 and 450L per day (451L per day being regarded as efficient water use for a house with four occupants and a medium garden) could be at slightly more than current prices, and usage greater than 450L per day could be significantly more expensive.
The current situation is that everyone is going to pay through taxes for desalination plants and other expensive methods of producing new fresh water. Having people pay for what they use is the capitalist way.
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