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How green is high-speed rail?

Ethan Elkind, director, Climate Program at Berkeley Law | July 1, 2010

highspeedrailLife cycle costs can be a buzz kill. Just when you think you’ve got a great environmental solution, such as going paperless and doing everything digitally, or installing double-paned windows to make a home more energy efficient, you find out that manufacturing these supposedly environmentally-friendly technologies can create waste that offsets some of their “green” value. The same may be true for high-speed rail. A new study by Mikhail Chester and Arpad Horvath of the Department of Civil and Environmental Engineering at UC Berkeley attempts to calculate the life cycle environmental costs of California’s proposed high-speed rail system. Compared to other modes of transit, the researchers found that:

High-speed rail has the potential to be the lowest energy consumer and greenhouse gas emitter only if it consistently travels at high occupancy or uses a low-emission electricity source such as wind, both of which will require appropriate planning and continued investment.

To ensure high ridership, high-speed rail will need to be affordable (low fares will encourage more riders), and towns and cities around the rail stations will need to plan for and legalize high-density, mixed-use development around the station areas. Both of these conditions will require strong leadership to meet.

As for the renewable energy, California has been working its way to more renewables through its renewable portfolio standards, which require investor-owned utilities to provide 20% of their electricity from renewable sources by this year (we’re not going to make it) and 33% by 2020. The 33% target, however, comes from the governor’s executive order under AB 32, the state’s global warming law which could be suspended this year by a ballot initiative. So the jury is out on the state’s ability to maximize its renewable production for uses like high-speed rail.

But leaving aside the life cycle costs, the Berkeley researchers note other benefits from high-speed rail. Says Chester:

Even if high-speed rail is ‘dirtier’ in some environmental aspects than other modes, you may still choose to build it for several reasons. These include transportation capacity constraints with the current infrastructure and the need to connect a growing number of cities, preferably avoiding developmental issues that have been identified with uncontrolled automobile growth.

While these other goals are important, high-speed rail leaders should ensure that the public is getting the maximum environmental benefit from the project, and that means ensuring high ridership and more renewable energy.

Cross-posted from Legal Planet.

Comments to “How green is high-speed rail?

  1. If you add it all up, it makes sense for “high speed rail” but the cost is very difficult to justify to the general public at the moment, especially when all governments are trying to pull out of a recession.

  2. A few excerpts from “Rail vs Auto Energy Efficiency” by David S.Lawyer:

    Intro: The railroad was originally invented because rail used far less energy than animal hauled carts to move heavy freight on dirt roads. “Railroads” were first used to haul coal from mines and were pulled by animals. The rolling resistance of a train (per ton of vehicle weight) is only a small fraction of that of an automobile or truck. Thus one would expect railroads to be a few times more energy-efficient than autos or trucks. While this is often true for the comparison with trucks, it’s seldom true when comparing a passenger train with the automobile.

    It turns out that in spite of it’s low rolling resistance, passenger trains in the US today (including rail transit) are not much more more energy efficient than the auto. It wasn’t always like this. From the late 1930’s thru the 1960’s diesel passenger trains were significantly more energy efficient than the auto. During World War II they were 2 to 3 times as energy efficient. Then in the 1970’s, federal mantdates greatly improved the energy efficiency of the auto. There were no federal mandates to improve rail energy-efficiency. To understand why rails are not as efficient as one might expect, it’s necessary to first understand various technical concepts, especially rolling resistance.


    6. Passenger Trains Are Heavy: The question still remains: Why aren’t passenger trains more energy efficient if their rolling resistance is so low? There are a number of reasons, the major one being that trains are usually much heavier than autos (on a per passenger basis). Previously, the units used were rolling resistance per unit weight. If one takes into account the weight of the train per passenger, and then examines the rolling resistance per passenger, the advantage of rail over the auto drastically drops. For a very heavy passenger train, it will even favor the auto.

    Just how heavy are passenger trains? There are various types of trains, some pulled by heavy locomotives and some that are driven by electric motors under each car. The ones pulled by locomotives tend to be very heavy and estimates made from US government data for 1963 (the government ceased collecting such data after that date) indicate about 3.7 tons/passenger. Automobiles are roughly one ton/passenger with an average of 1.6 persons/auto in an auto weighing 3,200 pounds. Thus rail was (in 1963) about 3.5 times heavier per passenger.

    If one compares a lightweight auto with a lightweight train car, the train car weighs about twice as much per seat. A lightweight auto will weigh about 2,000 pounds with 5 seats (0.2 tons/seat). The (mostly aluminum) BART car (for the San Francisco rail transit) weighed 30 tons with 72 seats (0.42 tons/seat). The percentage of seats occupied by passengers on trains, is often not much different than for automobiles.

    The Acela electric trainsets introduced by Amtrak in the early 21st century, are 2.1 tons/seat. This is ten times higher than that of a lightweight auto.

    The heavy weight of trains not only increases rolling resistance, it also increases the energy used for climbing up a grade or accelerating from a stop. If the weight triples, so does such energy use.


  3. I wonder if this includes the reduction on carbon over the life of the asset… and if it includes the amount of carbon offset by all of the riders whom otherwise will be either taking a higher pollutant vehicle, etc.

    If you add it all up, it makes sense for “high speed rail” but the cost is very difficult to justify to the general public at the moment, especially when all governments are trying to pull out a recession.

    Ridership will be low at a high ticket price, hence politicians will not be able to convince tax payers of such initiative… unless it can be built fast and subsidized by tax base for ridership… it will then definitely increase the ridership and help offset carbon.


  4. One worst case scenario cause of unacceptable Climate Changes that we are experiencing in California and around the world today is that over 50 years ago UC failed to dedicate all necessary scientific resources to protecting and preserving quality of life in the long term for all future generations by achieving Teller’s promise of fusion energy in the 20th century.

    Instead, UC dedicated itself to short term profitability programs from building Holocaust bombs to BP oil alliances.

    So today, the consequences are that we are forced to nitpick the pros and cons of “green” wedges like high-speed rail while we continue to run out of clean water due to our failures to build desalination plants, and dust bowlification of agricultural lands in areas like Fresno at accelerating rates.

    Yet UC continues to fail to do the right things for humanity today because academic rhetoric is still cheap and takes no real effort, while positive actions to implement long term solutions ASAP to save humanity take hard work and dedication.

  5. High Speed Rail will have a major, positive economic impact. Not only are the short- term design, engineering and construction benefits important, especially in these pressing economic times, but also, there is the long-term advantage to a region that is served by High Speed Rail. While the numbers vary and are, indeed, debatable, most experts agree there will be a positive benefit.

    Instead of debating the details—$19B, $34B, $7B—let’s focus on the other side of the equation, which is, what happens if we do not build a new system? Most of our regional centers of economic activity are increasingly paralyzed in ever increasing traffic congestion. Our airports are increasingly over-crowded, making it more and more difficult to meet the public and especially the business community’s need for intra-regional travel. When these congestion delays become too great, the business community and the resultant jobs will look elsewhere.

  6. these supposedly environmentally-friendly technologies can create waste that offsets some of their “green” value.

  7. You’re on the right “track.” Decisions based on fact are so much harder that those based on perception. But wait, maybe there is a solution; a nice fusion or fission power plant buried in the Central Valley to produce electricity where the sun don’t shine and the wind won’t blow. By-the-way, the electricity could also be used to pump the Delta dry or at least pump some of the water south up the big hill to So-Ca. Wow, then how about a hydro-plant at the bottom of the hill, say Burbank, to recover the excess electrical energy that could be used to power our TV and movie production so we have something to watch on our big screen TV’s in our sub-cooled homes. Don’t give up, there are answers, we just haven’t found how they will benefit us yet. Choo, Chooo “I hear the train comming down the track.”

  8. Even your wind and solar power has sunk carbon costs; most of those windmills and solar panels are manufactured with coal-generated electricity…add the energy cost of mining the materials, transportation, et al, youre heading into a stiff brown headwind…

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