Monday, October 10, 2011

Honolulu Heavy Rail Is an Energy Black Hole

Energy and Honolulu rail is an angle that I did not have time to look at in detail, until last week when my students did some energy analysis of Honolulu’s proposed rail. They discovered this June 2008 article by Sean Hao: Rail's use of energy subject of debate in the Honolulu Advertiser.

Of note is that the rail will consume about 20 MW of energy which is about 20% of the capacity of HECO’s new palm oil plant. Unfortunately peak rail travel coincides with peak demand for electricity around 6 PM, which means that rail will stress HECO’s generators.

Now if you believe the city’s numbers which are based on incredible ridership projections and substantial bus route eliminations, Table 4-21 of the Final EIS shows that the rail project will save 2,440 million British thermal units (BTU) of energy each day, or about 610,000 million BTU per year.

Hao correctly added that: “Any evaluation of the energy savings generated by rail also needs to consider the massive amount of energy required during construction. For example, construction of the fixed guideway will require between 3.7 trillion and 4.9 trillion BTU of energy, according to Parsons Brinckerhoff.”

This quote reveals two startling facts:

First the unnamed Parsons Brinkerhoff source clearly lied to Hao by stating roughly half the correct amount of BTU. The 2008 Draft EIS, Table 4-34 on page 4-159, shows that the rail’s Airport alignment will require 7,480,000 MBTU. That’s 7.5 trillion BTU, not 3.7 trillion.

Second, by dividing 7,480,000 by 610,000 we get 12.2. That’s how many years it will take to make up the construction energy loss by the purported energy savings. But in reality these 12 years are an understatement because Hawaii's vehicle fleet is much smaller in engine size (more economical) than mainland fleet and the adoption of hybrid and electric vehicles is vastly bigger on Oahu. In addition the national averages are based on low vehicle occupancy, whereas Oahu has among the highest transit and carpooling rates, so BTU per passenger mile is way lower than mainland.

The City's BTU savings estimate may be wrong by a factor of 3 or larger, so it will take so many years for rail to "make up" its construction energy waste that before break-even is reached, rail will need multiple component replacements, repairs and refurbishments. So an energy black hole it is!

On the other hand, our 2008 simulation estimates using the DEIS traffic numbers show that rail is a net energy loser without even counting the huge energy consumption during construction. In comparison, a properly designed and operated HOT lane system will save energy (motor fuel and oil.)

Fuel Consumption for One Peak Hour (in US gallons)
Change from Base of ~97,000 gallons


Motor Fuel

Motor Fuel plus Diesel at HECO for Rail

Rail: 6.5% traffic reduction



Rail: 3.25% traffic reduction



HOT Lanes and Four