Sunday, June 7, 2009

Plug-In Hybrids

In Toyota: Plug-in Hybrids Will Have Limited Appeal, Jim Motavalli makes the world of the Toyota much more complicated, at least until we look at things a little further. I wondered what the Toyota people had in mind during their presentation. As a Prius driver myself, it seems to me that adding a large battery does not produce a difference in kind that would force a new brake design for example. More like having an extra passenger in the car, and that does not require redesign. Further, the extra weight only means that a driver adjusts his driving style once again. One of the wonderful features of the Prius and the Honda hybrid is that they offer enough instrumented feedback so that one can adapt one's driving patterns to get better mileage. One possibility is that they are trying to dampen some of the exaggerations about mileage. At an MIT symposium on the Smart Grid, I heard one speaker say that plug-in vehicles would get 150 miles per gallon equivalent. I did not believe that, and sought to clarify whether that number includes the inefficiencies inherent in production and distribution of electricity. The consensus in my area of the room was that it does not. Proper treatment of these inefficiencies would yield roughly 50 mpg equivalent, interestingly in alignment with the Toyota numbers. In other words, once again, it is very difficult or impossible to get something for nothing, but it is possible to create the illusion of getting something for nothing. Toyota is to be honored if it is bucking this opportunity.

On a more skeptical note, one may consider that the Prius "crossed the gap" to adoption around 2003. At least, this is how Toyota and the auto industry saw things at the time...although I thought that judgment was a little premature. Recognizing this, one can also hypothesize that Toyota has a vested interest in protecting its offering. Some of the things Toyota people say may therefore be biased by this effort.

More broadly and technically, I see opportunity for better gas mileage with my Prius, but am a little skeptical of simple notions of plugging into the Grid as the source for those increased miles per gallon. Illusory miles per gallon, yes. Real miles per gallon, no. What I recognize is that, as I drive, there are some opportunities for better mileage as a result of a larger battery. At most this would be a 10% improvement, consistent with Toyota's projections. However, if one spends a lot of time in heavy urban driving, then the extra battery capability could be very valuable. Such driving is very draining on the batteries, and they can then be recharged when one gets out of the inner city. I have found the Prius to be better at battery life during such driving than is the Honda, so optimization can be done differently by different manufacturers, and Honda may have more opportunity in this area than does Toyota. Again, this is consistent with what Toyota has stated.

Where this all becomes very interesting is in interaction with the eventual Smart Grid. The vision for the Smart Grid is that car batteries interact with the Grid, calling for electricity when they are recharged during low-demand periods, and providing on-peak electricity when in the parking garage during peak hours during the day. Optimizing this system is not simple, because it is large and fundamentally statistical. We certainly want to avoid demanding more electricity if the amounts and timing will increase the production of greenhouse gases. Nevertheless, the vision has a chance of being accurate and is worthy of exploration.

Saturday, June 6, 2009

Methane from Cows

For some time now the anti-Green folks have been making a disproportionate issue about the methane issued by cattle breaking wind. The mere fact that methane is created and introduced into the atmosphere by natural means has served as an argument that there should be little or no effort to limit GHGs. Of course, this always was a bogus argument, because the mere fact that animals produce GHGs is of no account. If anything, it presents an argument for birth control, for limiting the populations of human beings and also of other animals. Now there is a lot more. A part of this is to do something about it, rather than using it as a trumped up excuse for doing nothing in any domain.

One approach is to recognize that the methane is a byproduct of somewhat less than efficient use the microbes in the cow's rumen. As with humans, microbes are a key part of the digestive process. No surprise there. It is the microbes that play a key role in converting the grasses indigenous to cow nutrition in to materials that can sustain the cow. In Australia, Dr. Athol Klieve noticed that another herbivore, the kangaroo, doesn't have a methane problem, presumably because it uses different microbes. So why not see if those microbes can be transfered to cows? This research is under way. See

Another approach is reported in today's New York Times: We get back to the question of what the indigenous feed may be for cattle. Well, it isn't corn and soybeans, the feed that has become normal in industrialized farming, and which would also produce gas in human beings. Does it come as a surprise that digestion is inefficient and leads to undesirable gases when the feed is not natural? What is natural is grasses. This article reports that alfalfa and flaxseed are much closer to what dairy cattle naturally consume. Is it surprising that replacing corn and soybeans as feeds with alfalfa and flaxseed yields an 18% reduction in gas?

The magnitude of the issue is summarized by the Times article. 'Frank Mitloehner, a University of California, Davis, professor who places cows in air-tight tent enclosures and measures what he calls their “eruptions,” says the average cow expels — through burps mostly, but some flatulence — 200 to 400 pounds of methane a year. More broadly, with worldwide production of milk and beef expected to double in the next 30 years, the United Nations has called livestock one of the most serious near-term threats to the global climate. In a 2006 report that looked at the environmental impact of cows worldwide, including forest-clearing activity to create pasture land, it estimated that cows might be more dangerous to Earth’s atmosphere than trucks and cars combined.' Here we return to the issue of expectations that the human and animal populations will continue to expand during the next decades. Can this really happen? Will it really happen? If so, there will have to be some serious resolutions to the challenges that we can already identify.

The plot gets even more interesting when one considers that it is the Omega-3 fatty acids in the flaxseed that have been identified as being the significant contributor to this effect. This goes to the refutation of the industrial chemistry approach to foods, holding that all are just chemicals. The shortcoming of this approach is at least that the chemists do not recognize all the chemicals that may be necessary. We already know about such fatty acids, because good medical doctors urge older people in America to take fish oil to get their Omega-3 to help prevent cholesterol problems. Andrew Weil, M.D. writes about this and many other dietary matters in Andrew Weil's 8 Weeks to Optimum Health: A Proven Program for Taking Full Advantage of Your Body's Natural Healing Power. A key phrase in the NYTimes article comes in the third to the last sentence. The analysis of the effectiveness of the approach entails analyzing fatty acids in the cows' milk. If the new regimen leads cows to produce more omega-3 fatty acids in their milk, then milk might even become a significant source of these fatty acids. This would make them better for people.