Comments leszekp has made

7 Words

Use less. Use it wisely. Think. Act.On Here's your chance to be the Pollan of climate change posted 1 year, 10 months ago 94 Responses

Ironic

McIntyre is best know for the paper he did with McKittrick that supposedly debunked the "hockey stick" temperature curve. But in the original version of another paper by McKittrick, he put the latitude in degrees into a formula that expected it in radians, completely screwing up their results. This was a much bigger math error than anything NASA has ever done.

http://crookedtimber.org/2004/08/25/mckitrick-mucks-it-up ...On The Wall Street Journal contradicts itself on global warming posted 2 years, 3 months ago 24 Responses

It's even worse than you think

The CAFE standards are based on the original EPA mileage tests, city and highway. The EPA modified the sticker numbers in the 1980s, and again recently, because nobody was getting anywhere close to the CAFE numbers in real life; but the original EPA test process is still being used to determine whether carmakers meet CAFE standards. So the CAFE numbers are about 20-40% higher than what car fleets are actually getting on the road.On But conservation isn't sexy and doesn't make headlines posted 2 years, 8 months ago 7 Responses

To greentiger

Here's a description of electrode wear in fluorescents:

"I have heard that there is a substantial cost to starting a fluorescent light fixture. When entering and exiting a room frequently, is it better to leave a fluorescent light turned on, or to turn it off when leaving each time? -- GEW

Whenever you turn on a fluorescent lamp, a small amount of metal is sputtered away from the electrodes at each end of the tube. These electrodes are what provide electric power to the gas discharge inside the lamp and sputtering is a process in which fast moving ions (electrically charged atoms) crash into a surface and knock atoms out of that surface. Because sputtering is most severe during start up, a typical fluorescent tube can only start a few thousand times before its electrodes begin to fail. To avoid the expense and hassle of having to replace the tube frequently, you shouldn't cycle the lamp more than once every ten minutes. If you will only be away for a minute or two, leave the lamp on. But if you will be away for more than about ten minutes, turn it off. Incidentally, the claim that a fluorescent lamp uses a fantastic amount of electric power during start-up is nonsense. It's just a myth."

Source: http://72.14.253.104/search?q=cache:q1_qsj39OS8J:landau1....

Here's another reference:

http://ecmweb.com/mag/electric_rf_lighting_tunes/On Introducing the 'How Many Legislators Does it Take to Change a Lightbulb Act' posted 2 years, 10 months ago 11 Responses

A few responses

"The cars are run on a dynamometer and the carbon content of the exhaust is measured with an electronic sensor."

You are correct - read the wrong reference (and can't blame alcohol). But the quality and calibration of the EPA sensors is going to be of a much higher caliber than that of a standard off-the-showroom floor. That's why Consumer Reports uses actual gas consumption instead of the vehicle's sensor data to calculate the true MPG. If the sensor numbers don't agree with the actual mileage/gas consumption numbers, the sensor numbers are wrong. Reality always trumps any measurement of reality.

Here's a link to a guy who monitored both his electronic mileage, and fuel consumption mileage, over several years for his 1st-generation and 2nd-generation Priuses, and found that the electronic mileage consistently overstated his true mileage (about 5%, averaged over time).

http://john1701a.com/prius/prius-data11.htm

"And trust me, if you get in your Prius and go outside and simulate the EPA simulation, you will get the same results on your car computer within a few percent one way or the other."

Uh, this is a meaningless statement - the test is not representative of true driving conditions, and there's no way to do this test in the real world, which is why the EPA is finally changing its test conditions. The testing conditions are a climate-controlled facility, no A/C, defroster or heater on, on a dynamometer so there's no hills either. Then the results are modified based on 1980s data to try and compensate for real world effects - the city mileage is decreased from its test value by 10%, the highway by 22%. And even these aren't enough - the EPA says that on average, people get about 14% lower overall mileage than the sticker numbers, and you can get as much as 25% less without there being anything significantly wrong with the car. Yes, you can get better numbers by changing your driving style - I get about 15% better combined mileage in my car than the EPA sticker values because I drive the right way. I wish everyone would drive the right way, but they won't. It's the real-world numbers that matter, not what people might be able to achieve if they drove the right way.

For that matter, the Prius's sensors and measurement system are different than that used by the EPA, so you have no basis for saying that you'll get the same numbers.

"Note on the link I reference that the Prius is averaging 48 MPG for a sample size of 1,016 cars with a standard error of 0.1, and that is not just for highway miles."

That's not unreasonable. However, in order to determine whether these numbers accurately reflect the true mileage, you would have to know:

• The mix of city/highway driving percentages
  
• The conditions under which the driving are done
  
• Most importantly, is this a representative sample? In other words, if you post your mileage at greenhybrid.com, are you a representative driver, or are your numbers skewed too high, or too low?

"City driving, as all new Prius drivers quickly realize, is where you get the lowest mileage."

After touting the EPA tests as reliable, it's odd you'd say something like this. Based on the EPA tests for the Prius, they assign it a city MPG of 61 MPG, a highway MPG of 51 MPG, and a combined MPG (weighted harmonic average) of 55 MPG. The touted advantage of hybrids is not their improved highway mileage, but the supposed fact that they get superior mileage in city driving conditions, which account for the majority of miles driven in the US (latest figure I heard was over 60%).

"If that 51.7 reading was the average for the 422 miles he just drove, then that was his real mileage, regardless of road conditions, air conditioning use, or headwinds."

In order for that to be true, there would have had to be a 3-gallon discrepancy in his consumption numbers. That's not realistic.

"The ways he could have screwed up are many."

Uh, this isn't rocket science. Fill up in Detroit, drive, fill up again, fill up at the end, add up total mileage, divide by gallons. The onus is on you to show that he screwed up; just because you don't like his numbers doesn't mean he got it wrong.

"I have calculated my car's mileage by hand only twice. Both times it came out very close to the computer, one high, one low, so I quit doing it."

Well, I've done it hundreds of times, even set up a spreadsheet to do it automatically to track my mileage. The hand-calculated mileage does vary a lot, but you'd expect it to, and that's consistent  with the results from the link above for the Prius. Your city/highway mix will change, weather conditions will change, your driving habits can change, and so on. I'd view an unvarying electronic mileage as more suspicious than a varying hand-calculated mileage.

I recall the Mythbusters episode where they looked at the effect of A/C on vs. windows open on fuel economy. Their electronic sensors showed that fuel consumption was lower with the A/C on vs. the windows open, while their actual driving test results (and those of GM and others) showed the opposite result - windows open is better than A/C on, even at highway speeds.

"Let's run some math. You pay 26K for your Prius instead of, say 14K for a, let's say, a Scion, and save, lets say 1K over ten years. That is 100 dollars saved per year, or $8.30 per month. If you save 2K, that's $16.30 per month and so on."

You need to re-think your math again. The average car in the US drives about 12,000 miles a year. Let's say the real-world MPG for the Prius is 48 MPG, and 22 MPG for the Scion. If you assume gas averages $4 a gallon over the next ten years (probably a low figure), you'll spend about $1000 a year on gas for the Prius, and about $1818 a year for gas for the Scion. If the Prius numbers are correct, you'd save about $65 a month, not the $16.30 you state. Over 10 years, that's a total of over $8000 in gas savings. If the Prius numbers are lower than that, particularly for the kind of driving you do, that could impact those savings tremendously.

But that's sort of irrelevant, because you have to figure in that you paid $12,000 more for the Prius than the Scion, not a trivial amount of money for most people. At the end of ten years, the depreciated value for both cars is going to be far lower, and the differential is going to be far less than the original $12,000. So the Prius costs you a non-trivial amount of money upfront, you save a non-trivial amount in gas cost every month, but at the end of the line you're lucky to break even financially. In terms of both money and environmental consequences, you'd be better off putting the money into efficient appliances and heating/cooling equipment, better insulation, etc..

"Uh, the Prius releases from its tail pipe five times less CO2 into the atmosphere than the Hummer?"

"People are replacing their gas-guzzlers with a Prius for both reasons."

Yeah, and a standard Honda Civic releases 3-4 times less CO2, and costs less. If you're like Laurie and Larry David, have multiple large houses at opposite ends of the country, and consume more than the average American as part of your standard lifestyle, than driving two Priuses doesn't compensate enough for your other excesses, and isn't enough to qualify you to preach to others about the dangers of CO2 and global warming. For these people, the Prius is a cloak to wear to hide their true impact on the environment from themselves and others. If you've already done everything else you can do in your home and lifestyle to cut energy consumption, then go buy yourself a hybrid and show off to the world. but if you haven't, then buying a hybrid as a sign that you care about the environment is fundamentally dishonest.

To donee:

Yes, I'm aware of the bladder, and how it can affect the gas tank volume. And yes, it is a good thing since it does reduce the VOC emission.s But this gas tank volume problem only occurs during periods of cold weather, when the bladder plastic becomes stiff and inflexible, and temperature differentials between different times of the day can be as large as your experience. The USAToday test was done in May or June, driving from Detroit to Washington DC, so the temperature effect would be minimal. In any case, the bladder effect would have to account for a 3-gallon discrepancy, and AFAIK, the most anyone has reported for this effect is one gallon, similar to what you report.

Once again: if your long-term overall mileage computed from gas consumption and distance driven differs from the electronic figures, then it's the electronic number that's wrong. Reality trumps any measurement of reality that doesn't agree with it.

"Why are "car" people so anti-Prius?"

First off, I don't know. I could guess that they see it as a threat to the concept of cars as expression of personality or power. Secondly, I'm emphatically not anti-Prius, or anti-hybrid. I think Biodiversivist's beef with the Weekly Standard and USA Today's articles is misplaced. He shouldn't be mad at the argument that hybrids get significantly lower mileage than the EPA claims; heck, he admits as much himself when he says that he gets lower mileage in city driving versus highway with his Prius, when the EPA numbers say the exact opposite. The argument he should be going after is the one in the Weekly Standard that says that the government shouldn't offer incentives for hybrid purchases and development. Long-term, hybrid, plug-in hybrid and full-electric vehicles are the only practical and sustainable solution for personal transportation. The government offers huge incentives, tax credits and deductions for non-sustainable fossil fuel technologies, which the Weekly Standard doesn't complain about - why should they now complain about far smaller financial incentives that move us in the right direction? I believe that one of the government's main roles should be to look 5, 10, 20 years down the road, see what the problems might be then, and work on encouraging technologies and behaviors that will forestall those problems.

There are also a lot of other factors in favor of the hybrid that time and space don't allow me to talk about. For example: if you argue financial savings based strictly on the current and projected future pump price of gas, hybrids have a  tough time justifying their increased cost to you on a personal financial level. But the true cost of gas to you isn't the pump price: you have to figure in tax credits and deductions to oil companies, the cost of a military intended at least in part to defend access to energy supplies, pollution effects and cleanup costs, the effective cost to replace gas as a source of energy when it runs out in the future, etc.. By one estimate made about 5 years ago, when the pump price of gas was roughly $1 a gallon, the true cost per gallon of gas was anywhere from $5 to $15 a gallon. Figured that way, the government should buy everyone in the US a hybrid vehicle, and the payback time for that expenditure would be surprisingly short. But nobody figures stuff that way, even if they should - too complicated to explain, I guess.

The problem I have with evangelists for any of the alternative transportation technologies is that instead of realistically presenting the benefits, and there are many, they will exaggerate those benefits and become incredibly hostile to those that point out that they are exaggerating. Hybrid evangelists are actually pretty good in that respect. Try telling a corn ethanol enthusiast, or a biodiesel enthusiast, or a hydrogen economy enthusiast, that there are serious issues with their "solutions", and stand back to avoid getting hit by the vitriol. Ignoring reality because it conflicts with your enthusiasm for an idea, or exaggerating the benefits of a "solution", is always going to wind up being a bad idea (c.f. the neo-cons and Iraq).On You may be surprised posted 2 years, 10 months ago 56 Responses

You really should take this post down

I'm sorry, but this is a bad post.

1. Your argument that the computer mileage gauge is somehow more accurate than that actually calculated by dividing the total mileage by gallons consumed isn't correct. Electronic sensors can be used as a general guide, but they can be thrown off by any number of factors. When the EPA says that the computer numbers are reasonable, they figure that out by averaging those numbers over a long distance, and then comparing them to the correct number, which they calculate by taking the total mileage and dividing that by the gallons consumed! That's also how they calculate the mileage in standard EPA tests - because they know there's no way to get an accurate results from standard auto electronic sensors. If the electronics give you one number for MPG, but mileage divided by gallons consumed gives you another MPG number, it's the latter number that's real, and correct.

2. Your argument that being a quart off on the fillup could change the MPG number calculated by 12.5 MPG is mathematically wrong. The gas tank capacity of the Prius is just shy of 12 gallons, or 48 quarts; if you're off by 1 quart, that will change the mileage calculated by 1/48, or a bit more than 2%. So, for the USA Today example, if the fillup were off by two quarts, more than the amount you state, it would still only affect the MPG calculated by less than 1 MPG, not the 12.5 you claim.

3. You may well average in the 50s for your Prius driving, and that's great, but you are the exception rather than the rule. For standard cars, the EPA reports that most people get about 14% poorer mileage than the sticker numbers, but they report that people get about 35% less than the sticker numbers for hybrids. There's a whole bunch of reasons for that, including the need to keep a hybrid engine running at stops when you're using either the A/C in summer, or the heater and defroster in the wintertime. Driving from Detroit to Washington in June, as the USA Today guy did, he was probably using his A/C, which certainly had an impact. That's one of the reasons the EPA will be changing their MPG testing procedures shortly - the old ones didn't take A/C, defroster, heater, low temperatures, hilly conditions, etc. into account, and gave a value higher than what most people get. Yes, you can meet or beat EPA numbers if you drive right, or in the right conditions - I get 15% better average mileage than the EPA numbers in fairly challenging conditions (cold weather, hilly terrain). But you judge typical mileage by the average, not the exceptional.

4. After badmouthing the USA Today argument that the Prius might not make sense from a financial standpoint, you then segue into an argument that financial issues don't matter, that a few hundred, or a few thousand, dollars over the lifetime of a car isn't going to make a difference to most people, and that people should buy a hybrid as a status symbol. Boy, that frosts me! First off, I'm not going to pay hundreds or thousands of dollars for a status symbol, especially if the environmental benefits aren't as good as advertised; I'll put the money into things like better insulation for my house, a new furnace, fluorescent light bulbs, etc., items that have the potential to save far more energy than any hybrid.  Secondly, how is spending more to buy a hybrid as a "status symbol" that much different philosophically than buying a Hummer, or Ferrari as a status symbol? You're not doing it because it benefits the environment, you're doing it because you think the people will see you driving the car and be impressed because it's "cool", it's "trendy". That's consumption for consumption's sake, and I thought we wanted to move past that kind of lifestyle. I especially dislike this attitude in the celebrity environmental enthusiasts like Laurie David, who make a fetish of driving a Prius, but otherwise live a lifestyle of significant consumption and multiple McMansions that collectively consume far more energy than any potential savings from driving a Prius.