R-Squared Energy Blog

Pure Energy

Three Gallons Per Mile

Often when I am flying, I think about the amount of fuel that the airplane is burning. Then when I am off the plane, I usually forget about it. I have heard mixed opinions on the overall efficiency of airline travel versus automobile travel, but just never got around to investigating the matter myself.

Earlier this month I was on a flight from Hawaii to Dallas, and the pilot started talking about some of the plane’s statistics. Paraphrasing, he said: “Today we will be cruising at an altitude of 38,000 feet in this Boeing 757. This aircraft burns about 3 gallons of fuel per mile, and is carrying 243 passengers.” I thought “Hey, I better write that down and figure out later on what my share of the fuel was.”

The distance from Honolulu to Dallas is 3,800 miles. Thus, per the pilot the fuel consumption should have been approximately 11,400 gallons. In the Wiki link to the Boeing 757 article above, the Boeing 757 specifications state that the plane only holds 11,500 gallons, so I think it is likely that we were really getting a bit better than 1/3rd of a mile per gallon.

Divided by 243 passengers, my share of the fuel is 47 gallons. This much fuel carried me 3,800 miles, so my pro-rated fuel economy is 81 miles per gallon. In all likelihood, as I said it was probably a bit better than that since I doubt we were landing in Dallas with only 100 gallons of fuel in reserve.

Of course it is important to note that while the fuel economy looks pretty good, the miles traveled are very high relative to automotive transportation. I generally travel less than 5,000 miles per year with my car, so if I drive a car that gets 25 miles per gallon it would only take about 16,000 miles on an airplane to equate to an entire year’s consumption in my car. I estimate that I have probably flown 300,000 miles in the past two years (which was one of the main reasons I left my last job).

One other item of interest to me is my prorated cost for fuel. At $2.00/gallon, $94 of my ticket price goes toward purchasing fuel, and every $1.00 increase boosts my pro-rated fuel cost by $47 for that Honolulu to Dallas trip. That’s actually surprising to me, as I would have guessed that it would have been more.

But that’s not really what hurts the airlines when fuel prices go up. I think what usually happens is that fewer people fly, and instead of pro-rating my share of the fuel across 243 passengers it may be prorated across only 180 passengers. In that case my share of the fuel rises to almost $200 when jet fuel rises to $3.00 per gallon – and thus a $1.00/gal rise in the cost of fuel translates into a several hundred dollar per ticket price increase.

November 30, 2009 Posted by | airline industry, airplane transportation, fuel efficiency | 44 Comments

An Urban Legend Falls

Figure 1. Classical Outlier or Amazing New Discovery?

On November 16, 2007 a study was released that stirred up a lot of excitement in ethanol circles. The study was titled Optimal Ethanol Blend-Level Investigation. The study was commissioned by the American Coalition for Ethanol (ACE), and the work was carried out by the University of North Dakota Energy & Environmental Research Center (EERC, a branch of the University of North Dakota) and the Minnesota Center for Automotive Research (MnCAR, a branch of Minnesota State University).

The study made some remarkable claims. Based on some data points – such as the point corresponding to E30 in Figure 1 above (which is Figure 10 in their report), they claimed that higher ethanol blends could get better fuel economy than pure gasoline. ACE captured their interpretation in a press release:

Study Finds Certain Ethanol Blends Can Provide Better Fuel Economy than Gasoline

“Optimal Blend” Is Likely E20 or E30; Coalition Calls for Further Government Research

Sioux Falls, SD (December 5, 2007) – Research findings released today show that mid-range ethanol blends— fuel mixtures with more ethanol than E10 but less than E85—can in some cases provide better fuel economy than regular unleaded gasoline, even in standard, non-flex-fuel vehicles.

Previous assumptions held that ethanol’s lower energy content should always directly correlate with lower fuel economy for drivers. Those assumptions were found to be wrong. Instead, the new research strongly suggests that there is an “optimal blend level” of ethanol and gasoline—most likely E20 or E30—at which cars will get better mileage than predicted based strictly on the fuel’s per-gallon Btu content.

Some of their “key findings:”

Ethanol’s energy content was not found to be a direct predictor of fuel economy. A fuel’s energy content in British Thermal Units (Btu) is current standard practice for estimating fuel economy, a method that, because of ethanol’s lower Btu value, leads to estimates of decreased fuel economy in proportion to the percentage of ethanol in the fuel blend.

• This research, however, did not find ethanol’s Btu content to be a direct predictor of fuel economy. All four vehicles tested exhibited better fuel economy with the ethanol blends than the Btu-value estimates predicted.

E20 and E30 ethanol blends outperformed unleaded gasoline in fuel economy tests for certain autos.
Contrary to Btu-based estimates of fuel economy for ethanol blends, three of the four vehicles tested achieved their highest fuel efficiency not on gasoline, but on an ethanol blend. Mid-level blends of ethanol E20 (20% ethanol, 80% gasoline) and E30 (30% ethanol, 70% gasoline) offered the best fuel economy in these tests.

• E30 offered better fuel economy than gasoline (a 1% increase) in both the Toyota and the Ford.

• E20 offered better fuel economy than gasoline (a 15% increase) in the flex-fuel Chevrolet.

• The non-flex-fuel Chevrolet more closely followed the Btu-calculated trend for fuel economy, but did experience a significant improvement over the trend line with E40 (40% ethanol, 60% gasoline), indicating that this may be the “optimal” ethanol blend level for this vehicle.

Standard, non-flex-fuel vehicles operated well on ethanol blends beyond 10 percent – All automakers currently cover the use of up to E10 (10% ethanol, 90% gasoline) by warranty for standard, non-flex-fuel vehicles. In this preliminary research, the three non-flex-fuel vehicles tested each operated successfully on ethanol blends significantly higher than this 10% ethanol level.

• The Ford Fusion operated on E45, the Toyota on E65, and the non-flex-fuel Chevy on E55. No engine fault codes were displayed until these levels were surpassed.

Of course these results are quite counter-intuitive, and I am always very careful when dealing with counter-intuitive results. Adding to the unusual results was the fact that the research was funded by a group whose purpose is to further ethanol, and the results of the study were certainly to be taken with a grain of salt. Note as well the spin. Look at Figure 1, and then consider the claim from the ACE press release: All four vehicles tested exhibited better fuel economy with the ethanol blends than the Btu-value estimates predicted. This is on the basis of that one point that looked to me like a classical outlier.

But that didn’t stop ethanol boosters from promoting the results. I have discussed these claims on numerous occasions, dealing with comments like these:

Ethanol has an Octane Rating of 113 AKI (compared to 86 for straight gasoline.) This means that even though it’s “energy content” is lower, it can achieve much greater Efficiency than gasoline when burned in a proper engine.

That’s why recent tests, such as the one performed by N.Dakota Univ, and Mn State, show that, when burned in newer vehicles, E20 gave slightly better mileage than straight gasoline in three of four cars tested.

If I had one of these three cars, and access to a blender pump, like they do in areas of S Dakota, Mn, Ia, and Wi, I could choose an ethanol product that would give me better mileage than straight gasoline.

If you can take any other conclusion out of that study You’re not being honest.

Some of my comments in response:

Now, what I would say about the study – but again, this is the objective view – is “That’s an interesting finding. Let’s replicate it in an independent lab that isn’t paid for by the ethanol lobby.”

Look at Figures 10-13. Here is the reality of the tests:

Figure 10. 2007 Toyota Camry, 2.4-L engine – 6 of 7 tests show worse fuel efficiency on an ethanol blend. There is one apparent outlier, which was the basis for the claims. (And it looks like a classic outlier, with almost all of the other points falling as predicted).

Figure 11. 2007 Chevrolet Impala (non-flex fuel), 3.5-L engine – 5 of 5 tests show worse fuel efficiency on an ethanol blend.

Figure 12. 2007 Chevrolet Impala (flex fuel), 3.5-L engine – 8 tests, 2 show better fuel efficiency, 2 show the same, and 3 show worse fuel efficiency on an ethanol blend.

Figure 13. 2007 Ford Fusion, 2.3-L engine – 4 of 5 tests show worse fuel efficiency on an ethanol blend. There is one apparent outlier.

So, what can we conclude? Of 25 data points, 18 confirm that the fuel economy is worse on an ethanol blend. That is 72% of the tests, and these tests were paid for by the ethanol lobby (which is why I suspect the results were spun as they were). The outliers are interesting enough for further investigation, but you have vastly overstated the test results. In reality, if you pulled the results out of a bag, you have only a 28% chance of improving your fuel efficiency on the basis of any particular test. Further, the outlier didn’t always occur at the same percentage, which would be quite problematic even if the result is confirmed.

So the ethanol boosters were perhaps not surprisingly ready to take these results at face value, arguing that it makes sense to boost the ethanol blended into our gasoline. I will say that if you could get better gas mileage on E20 than on pure gasoline, it would in fact be a strong argument in ethanol’s favor. But given that it is such a counter-intuitive result, it needed to be replicated. As a reader recently pointed out to me, NREL tried and failed:

Effects of Intermediate Ethanol Blends on Legacy Vehicles and Small Non-Road Engines

The key findings from the NREL test:

• All 16 vehicles exhibited a loss in fuel economy commensurate with the energy density of the fuel.*

• Limited evaluations of fuel with as much as 30% ethanol were conducted, and the reduction in miles per gallon
continued as a linear trend with increasing ethanol content.

*This result was expected because ethanol has about 67% of the energy density of gasoline on a volumetric basis.

Note that NREL is pro-ethanol, and the goals of blending more ethanol into the U.S. gasoline supply would be more easily accomplished had the ACE-sponsored study been confirmed. Instead, the NREL study gave the expected results: As more ethanol was blended, the fuel economy fell commensurate with the energy density as a linear trend. None of the outliers found in the previous study were observed.

My calls for caution on the initial tests were sometimes misrepresented:

I post a test conducted by two fine Universities, and you denigrate the students, and professors who conducted the tests (using the EPA cycle) as Biased.

Of course I never denigrated the students or professors involved. I said that based on the counter-intuitive results, and the fact that a vested interest paid for the research, we needed independent confirmation. There are all kinds of possible sources of error in scientific testing, which is why unexpected results need to be confirmed. The cold fusion fiasco is a perfect example of why we do this. Instead of waiting for confirmation, Pons and Fleischmann took their very unexpected results to the press. This tactic blew up in their face when other researchers failed to replicate the results.

A call for replicating results is not an insinuation that anyone faked the tests; it is instead simply because tests can be wrong for many different reasons. I can tell you that if the American Petroleum Institute conducted a test and found the opposite – that fuel economy dropped more than one might expect – I would expect ACE to denounce the tests and call for more testing.

At this point, I think it would be foolish for ethanol boosters to continue pushing the results of the initial tests. I would still like to see some additional work done in this area, because there is evidence that ethanol can perform at a higher economy than expected if it is used in a high-compression engine. But there is no reason to believe that an ethanol blend in a normal gasoline engine can give better fuel economy than can pure gasoline – which is exactly how the results of the ACE study were spun.

September 13, 2009 Posted by | American Coalition for Ethanol, American Petroleum Institute, ethanol, fuel efficiency | 144 Comments

Notes on Energy Efficiency

I arrived in one piece in Hawaii a few days ago, and have been settling in. It is still hard to believe I am here, and I plan to elaborate a bit on why I am here in the near future.

In the interim – and because I haven’t posted anything new in a few days – I thought I would call attention to a story in the New York Times from a couple of days ago:

Energy Efficiency: Fact or Fiction?

You have to be registered to read it (although the Tehran Times has reprinted the first page of the article) but I will paraphrase/excerpt it. The article covers a number of facts and myths around energy efficiency:


1. Screen savers save energy

FICTION — With screen savers, electricity is still pumping to keep your computer and monitor running. In fact, screen savers may even use more energy than a basic blank screen.

2. Your computer stops using energy when in sleep mode

FICTION — Computers still use energy when in sleep mode, but about 70% less.

3. You waste more energy restarting a computer repeatedly than letting it run all day

FICTION — Even though a small surge of energy is required to start up a computer, this amount is less than the energy consumed when a computer runs for long periods of time.


4. No energy is used after you turn appliances and electronics off

FICTION — Many appliances still draw a small amount of electricity when turned off. Solve this by plugging into a power strip that you can turn off.

5. It’s more efficient to keep your refrigerator full than half full

FACT — The larger the mass of cold items in a refrigerator or freezer, the less work is required to maintain the appliance’s chilly temperature. (Of course the more work it then takes to get the appliance to its chilly temperature).

6. Hand-washing dishes is more energy efficient than a dishwasher

FICTION — Dish washing by hand actually consumes more water and energy. People typically leave the hot water running, using up to 14 gallons of water on average. GE Appliances’ Paul Riley says to get the most out of an energy-efficient dishwasher, make sure it is fully loaded with food scraped off the plates.

7. Wash clothing with hot water for a truly effective wash.

FICTION — Heating the water for laundry makes up about 90 percent of the energy used in a conventional top-load washer. Using warm and cold water can be just as effective and can slash your energy use in half or more.


8. It’s better to fill your gas tank halfway because a full tank adds weight and is therefore less fuel efficient

FACT — The lighter your car, the better the fuel economy.

9. If you live in a warm climate, buy a light-colored car.

FACT — The lighter colors reflect the heat, whereas dark vehicles absorb heat and require more air conditioning to cool down.


10. If you live in a warm climate, paint your house a light color

FICTION — A light-colored roof helps dial back the temperature in a home’s attic by reflecting sunlight, but insulation is the key factor when it comes to energy savings. To really cool down your house, focus on proper insulation and plant foliage to block the sun’s rays.

11. Shut the door and vents in unused rooms

FACT — This works only if you close the doors and vents in multiple rooms.

12. Leave the heating or cooling system on all day. If you shut it down when you’re away, the system needs a surge of energy to reach the desired temperature.

FICTION — Switching the thermostat off when you go to sleep or leave for the day will boost energy savings. It will take more energy to bring your house back to the set temperature, but less energy is used during the down times. You can also realize substantial savings by changing the temperature settings. It is estimated that you will realize a 2 percent savings on your energy bill for every degree you cut back.

August 18, 2009 Posted by | electricity, electricity usage, fuel efficiency | 19 Comments

A Better Alternative to Cash for Clunkers

Today is my last day of work as Engineering Director for Accsys Technologies/Titan Wood. After today, I will continue to maintain an advisory relationship with the company, as I still thoroughly believe in the company and the technology, and I want to help them succeed.

However, tomorrow I board a plane to Hawaii to begin a new role. I have discussed that role briefly in the past, and will elaborate on it in the future. But that’s not what this post is about.

For the past year and a half, I have managed to live without a car. I was able to do that because I spent so much time overseas, and I didn’t need a car in those situations. I walked, I biked, I rode a bus, or I took the train. At times I have needed a car here in the U.S., and when I did, I rented one. But once I get to Hawaii, I think my days without a car have to come to an end. Before I go to work each morning, I have to drop kids off at two different schools, and the area I will live in gets a lot of rainfall. Therefore, I have decided to go ahead and get a car.

Previously, when I was considering getting a car, I asked readers for suggestions. In fact, it was a year ago this week that I thought I was going to have to buy one, so I put up a post asking for suggestions. Some pretty good suggestions came out of that post, but I ultimately decided to postpone my purchase. I don’t believe I can postpone it any longer, so I will start shopping for a car shortly after my arrival. (Again, suggestions are appreciated).

As I began my preliminary search on the Internet, it seemed to me like there weren’t that many good deals to be had for what I was looking for. Unfortunately for me, I don’t drive a clunker, so I am not eligible for those recent stimulus funds that were made available. And because the stimulus funds have driven demand to the highest levels in quite some time, it seems to me that dealers aren’t likely to be as amenable to offering a good deal to me, as opposed to someone who will bring in a $4,000 stimulus check. This has left me wondering, “Where’s my stimulus?”

I am certainly not opposed to incentivizing the purchase of fuel efficient vehicles. In fact, I have suggested before that the government offer rebates for vehicles that achieve certain levels of fuel efficiency. You could pay for these rebates with a penny a gallon gas tax, which would bring in upwards of $1 billion a year. If you then turned around and used that money to offer $1,000 rebates on the first million cars sold each year (out of a total of 7-8 million passenger vehicles sold in the U.S.) that meet certain fuel efficiency standards, you would incentivize fuel efficiency.

Instead, what we have done is to reach into a seemingly bottomless well of deficit spending and offer up overly generous incentives to just those who were driving old clunkers that probably weren’t going to be on the road that much longer anyway. The fact that the first $1 billion was gone in less than a week should tip the government off that they were throwing far more money at this issue than was necessary.

That was the point of my recent post criticizing the Cash for Clunkers program. It isn’t that I don’t agree with the intent, it is just that we spent far too much for what was achieved. As I pointed out in that essay, based on the projections of fuel savings, we spent $13.89 for each gal/yr of gasoline saved. And by “spent”, I mean we increased the national credit card bill that is the deficit, and which we are going to hand to our children to pay. (Incidentally, that is by no means a partisan criticism; Bush ran up enormous deficits that will haunt us for years).

So there is my alternative to Cash for Clunkers. Increase gas taxes by a cent, and offer $1,000 rebates to everyone who meets specific fuel efficiency standards with their purchases. I would put a sliding scale on it so that cars that get 30 miles per gallon (mpg) get $1,000 and cars that get 40 mpg get $2,000. And if a penny a gallon wouldn’t pay for the program, increase it to two cents a gallon.

Boosting the fuel efficiency of the fleet should reduce gas consumption anyway, which means that even the most vehement anti-tax critic out there should see that the two cents may ultimately translate into a savings on the cost of gas. But it would also mean that we are paying for the program as we go along, instead of handing the bill to our children. We simply can’t continue to burden the next generation with debt, or their quality of life is going to be lower as a result of the choices we have made.

Note: As noted earlier, I am now in transition to Hawaii. I am not certain about how quickly I will have Internet access and reestablish communications. So this will be my last post for at least a few days, and maybe a week. I will be back online as soon as possible.

August 12, 2009 Posted by | cash for clunkers, deficit spending, energy policy, fuel efficiency, national debt, politics | 70 Comments

Answering Reader Questions 2009: Part 4

This marks the final installment of answers to questions recently submitted by readers. This final installment covers the impact of E10 on fuel efficiency, my general optimism (or lack thereof), algal fuel, thermodynamics and energy limitations, Accoya, and litigation. Once again, thanks to the readers who submitted questions, and thanks to those who helped answer them. Without the help I received, this might have been a 10-part series.

Here are the links to the previous installments:

Part 1 – Covered plasma gasification, natural gas projections, free energy, promising alternative energy technologies, and GTL

Part 2 – Covered coal-to-liquids, technology hype, green gasoline, refining improvements, allocation of money toward renewables, electricity consumption, the Automotive X Prize, Big Oil, cellulosic ethanol, and Exxon’s recent algae announcement

Part 3 – Covered advice to engineering students and some books I recommend

The Questions

Wendell Mercantile wrote: The average fuel economy in Minnesota, which mandates E10, was 11% worse than in Wisconsin where drivers are allowed to choose. Minnesota drivers actually went fewer miles, while burning more fuel to do it. Answer

Melanie wrote: Reading over your last Q&A session, you seemed pretty optimistic. Have the events over the course of the last 2 years left you with the same amount of optimism or more/less? Answer

Mike wrote: I know your stance towards algae biofuel companies, but I want to bring a company to your attention called PetroAlgae. (I couldn’t find a reference to them on your blog.) I think they’re pursing a very nice model of licensing instead of building and also combining food with fuel production. They are claiming that the proceeds from the proteins should almost cover the costs of the whole process. With your expertise (and maybe knowledge about their processes), could you say something about the feasibility of those claims? Answer

Evan asked: 1 How can a nation/person “create” more energy/matter, if they do not take it from another nation/person?

2 Will renewable energy be able to account for the fundamental law of conservation of energy/mass? Economically?

3 If the US is the least efficient user of highly demanded fossil energy, why is its currency(time) worth so much? Do Americans just work too much?

4 Will we see currency exchange rate changes, which are weighted more upon per capita (person) energy efficiency? Answer

James Clary asked: What do you think about the economist article about hardening soft wood?

How to toughen up softwood: A hard act to follow Answer

takchess asked: Q: Do you envision that there will be a lot of IP lawsuit once cleantech is mainstream? Do you think this will be or is a disincentive for investment in this area? Answer

The Answers


This one was debated at length in the comments following the question thread, but I just wanted to add that I have posted a guest essay on this topic before: Wisconsin Tops Minnesota. It was written by Gary Dikkers.

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That’s a good question. I suppose in general I am more optimistic over the short term, primarily because I saw a relatively fast response to high oil prices. People did cut back on consumption, which was encouraging. The downside is that we are still dealing with fallout from those high oil prices. Not that I have ever been someone who could entertain the thought of a multi-billion person die-off due to peak oil, but I feel better about the overall prospects for humanity. I don’t feel as optimistic about the prospects for the economy, though. I think we are approaching The Long Recession (and may have entered it). I have never seen such a poor job market before. This is going to be extremely tough for a lot of people who have gotten used to a certain standard of living.

I am seeing this first hand in the engineering ranks right now. Since I started my career, demand for engineers has always exceeded supply. Presently, that is not the case (as I am finding because I am still trying to place some engineers that we recently laid off). The Wall Street Journal just reported that 50% of this year’s college graduates do not have jobs. If the job market is to improve, we have to have a recovery. If recovery causes demand for oil to increase, prices are going to climb and the recovery may stall. Wash, rinse, repeat.

I think the way we live is going to change. That’s not necessarily pessimism, because the way we live has to change. I don’t think many people would suggest that our current consumption (and not just of oil) is sustainable. The pessimistic side of me says that the way we live will change because that change will be forced upon us in unpleasant ways (e.g., people simply no longer able to maintain their standard of living), instead of governments making wise policy moves to prepare us for a future in which cheap energy is no longer plentiful.

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I have heard of PetroAlgae, and just spent a bit of time on their website. Let me first say that I think upwards of 90% of the bioalgae companies out there are being highly irresponsible with their investors. The technology isn’t close to being capable of producing cost-competitive fuel, and we have companies grossly over-promising (or even committing outright fraud).

On the other hand, I do believe that algae can be a niche solution. The problem is that it is being pedaled as a scalable solution, and therefore companies are popping up all over the place to take investors money. Most will inevitably declare bankruptcy after a few years.

But let’s talk about the niches. In my opinion there are a couple of ways algae could work. If it is to be truly scalable so that it can be a big contributor to our fuel supplies, I only see one obvious path. Algae must be developed that can excrete oil. In this way, the algae can grow, you skim off the oil, and you avoid the materials handling nightmare of harvesting and processing the algae. But that is going to require new technology, and unfortunately the invention of new technology isn’t a given.

The second way that I think algae can work is if there is a valuable co-product that offsets the production costs. This is PetroAlgae’s claim. The problem I see with this approach is that it isn’t scalable. You are going to be limited by the ability to put co-product in the marketplace. If the co-product is sufficiently valuable (let’s say you engineer algae that can produce insulin), then you could indeed offset the expense of algae production. But as it scales, you start to flood the market with this valuable co-product, and it is no longer so valuable. Or, if the co-product is already a commodity, it isn’t going to command a high enough price to offset production costs. Thus, I think this approach will be limited to niches. The approach described in the previous paragraph is the only one I think can be scalable.

Specifically on PetroAlgae, let’s look at one of the claims made in the video hosted on their site. Executive VP Bill Haskell makes the claim that a commercial licensee of a PetroAlgae system can produce 1.5 million barrels of transportation fuel a year. Krassen Dimitrov has made a case (PDF warning) that I have yet to see seriously challenged that based on the solar insolation falling on the earth at best one might produce 1 gallon of algae-based fuel per square meter of area.

If we look at the 1.5 million barrel claim above, that ultimately translates into a land requirement of 15,560 acres for just growing the algae. That is a 24.3 square mile plot of land. To put that in perspective, this is a plot of land 4.5 times the size of the largest refinery in the U.S. (which also has a capacity of 140 times greater than that claimed for the algae production facility that occupies 4.5 times the amount of land). And we haven’t even begun to consider processing all that algae.

Bottom line? I think their claims are exaggerated. I suspect that if you asked them to produce data justifying that 1.5 million barrel claim, one would find that they are making projections from small experiments and don’t actually have data to back that up.

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Let me try to answer these questions all together, because they are driving at the same theme. This isn’t really about creation of energy. Both fossil fuels and biofuels are about harnessing solar energy. In the case of fossil fuels, that is solar energy that was gathered over millions of years and cooked at high pressures and temperatures by the earth. Discovery of this ancient solar energy provided a windfall of energy that most of us take for granted.

We know this windfall is going to run out some day, and we already don’t like the fact that we have to rely on other countries to sell us part of their windfall. So we try to come up with schemes for capturing that solar energy and processing it immediately. This can of course be done in many ways, from direct solar capture, through the growing and conversion of biomass into energy. Generally the attempts to use solar power in real time suffer from various shortcomings (as do fossil fuels). However, some of those shortcomings are masked by the fact that the solar power that is being capture in real time is supplemented to a large extent by that same fossil energy we are seeking to replace.

The core of the problem is that many people – and I would say that most of our political leaders – don’t really appreciate the huge differences in the net energy from fossil fuels and the net energy from most renewable fuels. I have seen schemes floated in which our fossil fuels are displaced by cellulosic ethanol. You know what’s missing from those scenarios? The energy to produce the cellulosic ethanol. When that is taken into account, the primary energy production required to run a world on renewable energy is far greater than the primary energy production required to run a world on fossil fuel. So we have to do one of two things. We have to get used to the idea of eventually using a lot less energy, or we have to find better schemes for converting sunlight. (Or we will have to devote huge amounts of manpower to energy production – diverting productivity from the rest of the economy). In the short term, we will continue to draw heavily upon our fossil fuel reserves, but that can’t last forever.

In closing, let me offer up an example of how primary energy would need to increase if we switched from the high energy returns offered by fossil fuels to the much lower energy returns of most fossil fuels. Here are some numbers I have put together in the past. In a fossil fuel-based society, the energy return is currently somewhere around 10/1. Of 85 million barrels per day, 8.5 million of those barrel equivalents were used to produce the oil. For the sake of this exercise, let’s assume that oil was used to make oil. That leaves us with a net of 76.5 million barrels with which to power the world.

[Note: Thanks to Engineer-Poet for pointing out a math error here.] Now, drop the energy return of that same society to a biofuel range of 1.3 to 1. We have to solve two equations here: Net Energy = Energy out – Energy in, and Energy return = Energy out/Energy in. Solving these two equations for a net of 76.5 million barrels of oil means we have to produce a total of 255 million barrels of oil equivalent. In the fossil fuel society, it takes 85 million barrels of total production to sustain it. In the low energy return society that approximates today’s biofuels, it takes 255 million barrels per day to sustain it. That means that if we tried to run the world on low energy return biofuels, we would need to triple the overall energy output over what we produce today.

People who say energy return doesn’t matter fail to grasp this point. Unless biofuels are able to substantially improve their energy return – or we have a huge reduction in consumption – a lot more resources are going to have to be devoted to the energy sector.

Of course caveats abound when using an energy return to evaluate a biofuel. As I pointed out in one of my essays on Coskata, it is also possible to have a very good energy return and not net out much energy. Consider an example in which you start with 100 BTUs of biomass, consume 99 BTUs of the biomass to convert it to 1 BTU of liquid fuel, and input 0.1 BTUs of fossil fuel in the process. You could argue that your fossil fuel energy return was 10/1, but your conversion efficiency was terrible. You started with 100 BTUs of biomass and ended up with 1 BTU of liquid fuel.

These are some of the considerations we have to undertake as we try to ramp up biofuels to displace fossil fuels.

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You probably knew this – which is why I imagine you asked the question – but I was interviewed for that article. The interview took place way back in January, and I had forgotten about it until someone sent me the link.

I thought the article captured the gist of the interview in a concise manner. The key points I make to people about Accoya are generally around the modification of the hydroxyl groups in the wood, and how that impacts the properties of the wood.

I do want to reiterate that despite the career change I am in the process of making, I still feel like Accoya is a fantastic product with a bright future. I will maintain an advisory relationship to Accsys/Titan Wood after I leave, so you will probably see me writing about it on occasion in the future.

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There are several lawyers who read this blog, and almost every time I make a negative comment about their profession, one or more of them sends me a note. And I will probably get one after this.

In my opinion, litigation is attracted to big piles of money. Even if 99% of lawyers only go after cases with strong merit, there are always going to be some lawyers ready to file a suit at the slightest whiff of cash. My feeling is that we have too many lawyers, and the marginal lawyer has to find a way to make a living. So we get more lawsuits than we should have.

There is a lot of money flowing into the clean tech sector, and there are many people jumping in who may not have a clear picture of who owns various IP. That is a prescription for lawsuits. So, yes, I do expect more lawsuits as clean tech goes mainstream. That is the society we live in. Will it be a disincentive to invest? I don’t know. I do know that the money that flows out of the sector and into lawyers pockets won’t necessarily be invested back into the sector. So there will be a drain in my opinion. It could be that it is a tiny fraction in relation to the overall investments. Let’s hope so.

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OK, as far as I know I got the ones that hadn’t been addressed already (either in previous essays or by someone else in the comments). If someone feels like they didn’t get a question answered, ask in the comments following this essay and I will try to address it.

August 9, 2009 Posted by | algal biodiesel, E10, eroei, eroi, ethanol, fuel efficiency, litigation, Peak Oil, PetroAlgae, thermodynamics | 141 Comments

What’s 72 Million Gallons Anyway?

I just read a story this morning suggesting that the “Cash for Clunkers” program is expected to reduce carbon dioxide emissions by only a trivial amount:

‘Cash for clunkers’ effect on pollution? A blip

While the focus of the story is that this won’t do much for climate change, this is the piece that attracted my interest:

America will be using nearly 72 million fewer gallons of gasoline a year because of the program, based on the first quarter-million vehicles replaced. U.S. drivers go through that amount of gas every 4 1/2 hours, according to the Department of Energy.

In the context of the amount of gasoline we use – 140 billion or so gallons per year (a bit less now because of the recession) – this amounts to only 0.05% of our annual gas usage. Experts have suggested that making sure tires are properly inflated could save 3% on gas usage, or 60 times the amount saved by “Cash for Clunkers” if the majority of people are driving around on under-inflated tires.

So, for $1 billion invested in the program, a savings of 72 million gallons means we taxpayers paid $13.89 for each gallon of gasoline/yr saved. Readers know that I am a big fan of much higher fuel efficiency, but $13.89 to save a gallon of gasoline per year? While this benefit will be spread over several years of gasoline savings, surely we can do better than this.

Even if – as one reader suggested – those cars would have been on the road for another 10 years, you are still paying over a buck a gallon for the savings. No doubt that stimulus funds can stimulate in the short term, but what happens when the tax bill comes due? Will we look back on that as a wise use of those funds?

August 5, 2009 Posted by | cars, climate change, fuel efficiency, global warming | 40 Comments

Thoughts on New Fuel Efficiency Standards

After I wrote The Problem with CAFE a couple of years ago, a lot of people concluded that I am against higher CAFE standards. That’s not exactly the case. In a nutshell, my problem with CAFE is that I feel like it addresses the problem from the wrong side of the equation. In light of the new announcements on stricter CAFE standards, this might be a good time to review the issue. First, the new policy:

Stricter mpg rules may be boon for automakers

By issuing rules aimed at sharply boosting vehicle gasoline mileage and slashing greenhouse gas emissions, experts say the Obama plan is just what carmakers need given the prospect of higher gas prices and worries about global warming.

Automakers, in fact, reversed decades of opposition to stricter mileage standards by supporting the administration’s new rules — likely spurred in part by the industry’s heavy reliance on bailout money from U.S. taxpayers. Auto executives, for their part, said they like the plan’s unified approach to rulemaking.

The plan’s 30 percent boost in fuel economy would translate into a 35.5 mile per gallon average for cars and light trucks in 2016, four years earlier than the existing law called for. New passenger cars sold here would need to average 39 mpg, up from the current 27.5 mpg. Light trucks, which include pickups and sport-utility vehicles, would need to average 30 mpg, up from 23.

So what could possibly be wrong with that? The problem I have with it is that it mandates that automakers build vehicles that people are not demanding. There are very fuel efficient cars available right now. In fact, that’s about all you see in Europe, and you can certainly get them in the U.S. Why is the demand high in Europe? High fuel prices. People demand fuel efficient cars when fuel prices are high, as we saw last summer when SUV sales plummeted and hybrids were flying off of the car lots. Europe doesn’t have to mandate that they are built; the demand is there. This was the thrust of my argument in 2007, and CNN has picked up on that theme as well:

Gas prices: The key to fuel economy

The Obama administration estimates these rules will add about $600 to the cost of a car. That’s on top of an estimated $700 added by changes to fuel economy rules that have already been enacted. All this may keep consumers from buying a new car, some say.

Also with fuel prices still low, consumers may want larger vehicles, but these will never be as efficient as small cars. Without soaring gas prices pushing drivers to conserve, it will be difficult for makers of larger vehicles to meet the administration’s efficiency goals.

“You could achieve the standards today with ultralight, really small cars,” said Jeremy Anwl, chief executive of the automotive Web site Edmunds.com, “but how many people are really going to buy those?”

“They’re continuing to focus on the wrong program,” said Todd Turner, an analyst with Car Concepts Automotive Research.

Bingo. The problem with this is that the end result may very well result in better fuel efficiency, but it will be an inefficient process. By making cars that aren’t in demand, you may increase the price of the larger cars (e.g. SUVs) that are in demand. This may shift demand to smaller cars. But this could be accomplished by my proposal to exchange higher fuel taxes for reduced income taxes.

I think that’s reality. But in the alternate reality where technology is magically mandated to fix problems, we get thinkers like this:

Obama’s fuel home run

America finally has a smart leader, not a good old boy from Texas and his sidekick who were in the hip pockets of the Saudis and oil interests at home and abroad. Yesterday’s announcement of dramatically enhanced fuel efficiency standards on vehicles recognizes that environmental, economic, trade and foreign policies converge and can be addressed all at once.

I think these sorts of stories are incredibly naive. I suspect everyone is for higher fuel efficiency. What these sorts of proposals suggest is that it is a painless fix. Detroit will bear the costs, while consumers can continue to drive their Lincoln Navigator, only now it will get 30 miles per gallon instead of 14. Somehow, this magic wave of the wand is going to do this, and Obama is a genius for recognizing it.

Heck, if it is that easy, I don’t understand why he didn’t mandate that all vehicles achieve 100 mpg. For that matter, I still can’t understand why we don’t mandate a cure for cancer.

May 21, 2009 Posted by | CAFE, fuel efficiency | 82 Comments

Fuel Efficiency of Ethanol in the Real World

There is a particular poster at The Oil Drum who frequently claims that a gallon of ethanol can replace a gallon of gasoline in a car. Although he denies it, his over-the-top defenses of corn ethanol are consistent with someone who is being paid to promote it. There is no objectivity on his part, ever. A good ethanol study is one in which the results are pro-ethanol, even if it is funded by the ethanol industry. A questionable study is one in which the results are anti-ethanol – regardless of who funded it or where it was published. It doesn’t matter if a study was done as a high school science project if he likes the results. On the other hand, he has rejected a peer-reviewed paper in Science because he didn’t like the conclusions.

Here he is making his fuel efficiency claims:

Ethanol has an Octane Rating of 113 AKI (compared to 86 for straight gasoline.) This means that even though it’s “energy content” is lower, it can achieve much greater Efficiency than gasoline when burned in a proper engine.

That’s why recent tests, such as the one performed by N.Dakota Univ, and Mn State, show that, when burned in newer vehicles, E20 gave slightly better mileage than straight gasoline in three of four cars tested.

Later in that post he wrote: “…it has been show that one gallon of ethanol can, in a newer engine, for all practical purposes, replace one gallon of gasoline (116,000 btus,)…

Here is the study he used to support his point:


The funny thing is that the tests with ethanol blends actually showed a loss of fuel efficiency on 72% of the trials, even though the test was sponsored by the American Coalition of Ethanol. This is comical considering that this particular person won’t accept any study remotely having any ties to oil companies. As I explained, here was what the test actually showed:

Without a doubt, you are embellishing the results. This is what I see from the ethanol tests. Look at Figures 10-13. Here is the reality of the tests:

Figure 10. 2007 Toyota Camry, 2.4-L engine – 6 of 7 tests show worse fuel efficiency on an ethanol blend. There is one apparent outlier, which was the basis for the claims. (And it looks like a classic outlier, with almost all of the other points falling as predicted).

Figure 11. 2007 Chevrolet Impala (non-flex fuel), 3.5-L engine – 5 of 5 tests show worse fuel efficiency on an ethanol blend.

Figure 12. 2007 Chevrolet Impala (flex fuel), 3.5-L engine – 8 tests, 2 show better fuel efficiency, 2 show the same, and 3 show worse fuel efficiency on an ethanol blend.

Figure 13. 2007 Ford Fusion, 2.3-L engine – 4 of 5 tests show worse fuel efficiency on an ethanol blend. There is one apparent outlier.

So, what can we conclude? Of 25 data points, 18 confirm that the fuel economy is worse on an ethanol blend. That is 72% of the tests, and these tests were paid for by the ethanol lobby (which is why I suspect the results were spun as they were). The outliers are interesting enough for further investigation, but you have vastly overstated the test results. In reality, if you pulled the results out of a bag, you have only a 28% chance of improving your fuel efficiency on the basis of any particular test. Further, the outlier didn’t always occur at the same percentage, which would be quite problematic even if the result is confirmed.

Apparently for you, this is like pass/fail. If we have 4 data sets, and in each set 1 of 10 points showed a positive result, you claim 100% positive results. I won’t say that’s dishonest, but it is definitely putting the best possible spin on the situation. And while it seems that the matter is settled for you, what I would do as a next step is hone in on those outliers and see if they can be consistently replicated. Unless they are, you may be banking your claims on nothing more than experimental error, as the tests showing the desired result were in the minority.

That hasn’t stopped this person from continuing to argue that we should go to higher ethanol blends, since this study shows the benefit. Of course there have been plenty of (objective) tests that do show the expected drop in fuel efficiency when using ethanol, including this one from Consumer Reports: The Ethanol Myth.

But today it came to my attention (via an essay by Geoffrey Styles) that a study recently published by Oak Ridge National Labs (ORNL) is the latest to show that you lose fuel efficiency on ethanol blends:

Effects of Intermediate Ethanol Blends on Legacy Vehicles and Small Non-Road Engines

E.4.1 Fuel Economy

• All 13 vehicles exhibited a loss in fuel economy commensurate with the energy density of the fuel.* With E20, the average reduction in fuel economy (i.e., the reduction in miles per gallon) was 7.7 percent compared to E0.

• Limited evaluations of fuel with as much as 30% ethanol were conducted, and the reduction in miles per gallon continued as a linear trend with increasing ethanol content.

Of course my friend will just respond that ORNL is clearly biased against ethanol and that the study is ridiculous. Either that or he will cherry-pick any favorable results, promote them, and ignore the unfavorable results.

So, while it is true that in theory one could make up some of the BTU deficit by going to engines with higher compression ratios – as I argued in All BTUs Are Not Created Equally – in the real world with real world engines the BTU penalty has to be paid.

Incidentally, the essay by Geoffrey Styles that I referenced earlier makes an interesting point. The ethanol industry is requesting an increase in the percentage of ethanol allowed for blending into gasoline from 10% to 15%. As Geoffrey points out, this is like a hidden tax on consumers, but the tax goes to the ethanol companies. The federal government actually loses out on the deal as well: “At the current average gasoline pump price of $1.93 per gallon, this would effectively raise the price by 3.4 cents per gallon, while reducing federal tax revenue by 2.2 cents.”

Given the power of the ethanol lobby in this country, we will probably end up doing it.

March 7, 2009 Posted by | energy policy, ethanol, fuel efficiency | 102 Comments

All BTUs Are Not Created Equally

I sometimes have to pause and remind people that I am not anti-ethanol. As I have said numerous times, I am opposed to recycling fossil fuel into ethanol, and paying massive subsidies to do it. This is what we do with corn ethanol. That is a false solution to our fossil fuel dependence. If we could produce corn ethanol as we can sugarcane ethanol – with minimal fossil fuel inputs – that would address the vast majority of my ethanol objections. I think I made that clear over two years ago with my support for E3 Biofuels attempt to produce corn ethanol in a more sustainable fashion.

But ethanol has one particularly compelling argument: Ethanol has a high octane rating (103), which means it does not easily pre-ignite. This means higher engine efficiencies could be obtained than can be achieved with gasoline.

It is known that ethanol added to gasoline normally causes the fuel efficiency to drop. Ethanol contains about 2/3rds of the BTUs (heating value) as the same volume of gasoline, and gasoline/ethanol blends normally shows the drop in fuel efficiency one would expect. However, because of ethanol’s resistance to preignition, it should be theoretically possible to design an engine with a much higher compression ratio, which could then extract more useful work from the ethanol. Diesel engines are designed with high compression ratios, which is the key to their engine efficiencies of around 45%, versus 25-30% for a gasoline engine.

Let’s take a simple example, to show how ethanol’s BTU deficit could be made up with an increase in engine efficiency. Gasoline contains about 115,000 BTUs/gallon. If the engine efficiency is 25%, then 28,750 BTUs/gallon ultimately power the vehicle. The rest are expelled as heat. Ethanol contains about 75,000 BTUs/gallon. One could in theory achieve the same fuel efficiency with ethanol as with gasoline if an engine was designed with an efficiency that resulted in the same 28,750 BTUs/gallon powering the vehicle (assuming same weight, frictional losses, etc.) That means that if the efficiency of the ethanol-powered car was 28,750/75,000 – or 38.33%, then 1 gallon of ethanol could provide the same power to the vehicle as 1 gallon of gasoline. And of course if the efficiency of the ethanol vehicle could be increased further, it is possible to use 1 gallon of ethanol to travel farther than one could travel on 1 gallon of gasoline – despite the BTU deficit.

This has been true in theory, and some small scale engines have been created. The Saab Biopower, which debuted a couple of years ago, showed that the BTU-deficit could be partially compensated for. The Saab engine was designed with a higher compression ratio, so that on E-85 it showed a 12.5% drop in fuel efficiency instead of the typical 20-30% drop that one typically sees on E-85. The Saab also achieved a reported 20% extra power and 15% extra torque from this engine.

But I was recently made aware that Swedish automaker Scania has been producing ultra-high compression ratio engines designed for ethanol usage, and they reach engine efficiencies as high as 43%:

Scania’s Ethanol Diesel-Engine, Runs On Biodiesel Too

That means that if all else was equal (no significant weight penalty from the high-compression engine), a gallon of ethanol could enable a vehicle to travel farther than it could on a gallon of gasoline.

In reality, the comparison is not quite apples and oranges, as these Scania engines are used in heavy, commercial applications. I wrote to the company a couple of months ago and asked them some questions about any possible plans to produce a smaller engine for passenger vehicles, but they never responded.

But the point of the essay was to show that all BTUs aren’t the same for liquid fuels, and that a modified compression ratio has the potential to give the counter-intuitive result that a fuel with few BTUs per gallon can actually provide better fuel efficiency in some cases.

January 20, 2009 Posted by | compression ratio, diesel engine, ethanol, fuel efficiency, octane, Scania | 96 Comments

How Quickly We Forget

Retail gasoline prices in the U.S. peaked back in July at $4.17 a gallon. (Source: EIA). At the end of 2008, gasoline had fallen to $1.67. We typically use about 140 billion gallons of gasoline each year, so that $2.50 drop amounts to an annualized difference of $350 billion in the pockets of consumers – and into the U.S. economy instead of the economies of Saudi Arabia and Venezuela. Add in the drop in diesel, home heating oil, and jet fuel and you are looking at half a trillion dollars. And while I am strongly in favor of raising gasoline taxes to reduce our fossil fuel consumption (and demand has been sharply down as a result of high prices), the economy can certainly use this sort of stimulus right now.

But in the long run it is very important how people use that money. And we seem to be reverting to bad habits. How quickly we forget $4 gasoline:

Big is back: As pump prices plunge, SUV sales surge

NEWPORT NEWS – It looks like the Highlander is in and the Prius is out — for now at least.

Trucks and sport utility vehicles will outsell cars for the first time since February, according to a December report by Edmunds.com, which tracks industry statistics.

“Despite all the public discussion of fuel efficiency, SUVs and trucks are the industry’s biggest sellers right now as a remarkable number of buyers seem to be compelled by three factors: great deals, low gas prices and winter weather,” said Michelle Krebs of AutoObserver.com, a division of Edmunds.com, in a prepared statement.

And the punch line:

The surge in SUV and truck sales suggests that the issue of fuel efficiency has faded in the minds of many consumers.

Toyota has already slowed production of the industry’s flagship hybrid vehicle, the Prius, due to lack of interest and a growing inventory of the once best-selling model, Edmunds.com reported.

All this might mean a setback for fuel-efficient models that were heralded as a remedy for the country’s addiction to oil.

If people are going to flock back to gas guzzlers instead of using their extra pocket money to pay down their debt, then I would rather gas prices go ahead and recover. Based on the trends in vehicle sales, I am sure I will see that wish fulfilled before too long.

January 4, 2009 Posted by | fuel efficiency, gas prices, Prius | 56 Comments