Category Archives: Transportation

Energy Literacy

I was impressed in 2007 by the following chart in Scientific American, which shows where our energy in the U.S. comes from and how the energy is used in electricity generation and in four consumer sectors. One conclusion is that more than half of our energy is wasted, which is clearly shown in the bottom right corner of the chart. However, this result shouldn’t be surprising.

2007 USA energy utilizationSource: Scientific American / Jen Christiansen, using LLNL & DOE 2007 data

The waste energy primarily arises from the efficiencies of the various energy conversion cycles being used. For example, the following 2003 chart shows the relative generating efficiencies of a wide range of electric power sources. You can see in the chart that there is a big plateau at 40% efficiency for many types of thermal cycle power plants. That means that 60% of the energy they used is lost as waste heat. The latest combined cycle plants have demonstrated net efficiencies as high as 62.22% (Bouchain, France, 2016, see details in my updated 17 March 2015 post, “Efficiency in Electricity Generation”).

Comparative generation  efficiencies-Eurelectric 2003Source: Eurelectric and VGB PowerTech, July 2003

Another source of waste is line loss in electricity transmission and distribution from generators to the end-users. The U.S. Energy Information Administration (EIA) estimates that electricity transmission and distribution losses average about 6% of the electricity that is transmitted and distributed.

There is an expanded, interactive, zoomable map of U.S. energy data that goes far beyond the 2007 Scientific American chart shown above. You can access this interactive map at the following link:

http://energyliteracy.com

The interactivity in the map is impressive, and the way it’s implemented encourages exploration of the data in the map. You can drill down on individual features and you can explore particular paths in much greater detail than you could in a physical chart containing the same information. Below are two example screenshots. The first screenshot is a top-level view. As in the Scientific American chart, energy sources are on the left and final disposition as energy services or waste energy is on the right. Note that waste energy is on the top right of the interactive map.

Energy literacy map 1

The second screenshot is a more detailed view of natural gas production and utilization.

Energy literacy map 2

As reported by Lulu Chang on the digitaltrends.com website, this interactive map was created by Saul Griffith at the firm Otherlab (https://otherlab.com). You can read her post at the following link:

http://www.digitaltrends.com/home/otherlab-energy-chart/

I hope you enjoy exploring the interactive energy literacy map.

The Cargo Bicycle – An Idea Whose Time Has Come, or Has it Been Here All Along?

There has been increasing interest in the U.S. in cargo bicycles for making pickups and deliveries, particularly in inner cities with high traffic volumes and limited parking. Human or electric-powered cargo bicycles offer obvious environmental advantages over traditional, much larger gas or diesel powered delivery vehicles.

In February 2017 IKEA will be introducing a multifunctional, affordable, “city bike” called the Sladda. In addition to IKEA’s own interpretation of conventional bicycle features, the Sladda can be equipped with a variety of cargo carriers:

  • Front basket that’s rated at 10 kg (22 pounds)
  • Rear rack that’s rated at 25 kg (55 pounds)
  • Clip-on pannier (bicycle bag), which requires rear rack and converts into a backpack
  • Trailer that’s rated to haul 49 kg (108 pounds).

The rated load of the bicycle itself is 160 kg (352 pounds), including the weight of rider.

IKEA Sladda-2

Sladda configured as a cargo bicycle.  Source: IKEA

You’ll find details on the Sladda on the IKEA website at the following link:

http://www.ikea.com/us/en/

Xtracycle offer the Cargo Node and Edgerunner cargo bicycles. The folding Cargo Node, shown below, has a 159 kg (350 pound) carrying capacity, including the weight of the rider. The Edgerunner is a non-folding bicycle with a 182 kg (400 pound) carrying capacity. Both can be configured with a variety of racks. You’ll find more information at the following link:

http://www.xtracycle.com

 Xtacycle cargo bikeCargo Node.  Source: Xtracycle

Cargo bicycles may be trending in the U.S., but they have been used for many decades in Europe, particularly in Scandinavian countries, and they probably have been used just as long in Asia.

On a recent trip to China and Cambodia I found that 2- and 3-wheel cargo bicycles were very common and some were capable of carrying impressive loads. It seemed the concept of “rated load” never was an issue. Also common in China and Cambodia were 3-wheel cargo scooters and a range of small cargo vehicles that were part motorcycle and part truck. These small cargo vehicles seemed well suited for use in very high volume, relatively slow moving city traffic. Following are photos of several of the cargo bicycles, scooters and motorcycles I saw on the trip.

The cargo bicycles offered by IKEA and Xtracycle are nice, but they really don’t break new ground in the use of bicycles as cargo carriers. What is new is that individuals and businesses in the U.S. are expressing increasing interest in cargo bicycles, and other forms of small urban delivery vehicles. Next time you’re stuck in city traffic, you may be passed by a cargo bicycle in the bike lane.

Basic cargo bicycleBasic cargo bicycle in Xi’an, China

Streetsweepers cargo bikeStreet sweeper’s cargo bicycle in Xi’an, China

Cargo bike with cardboardCargo bicycle in Xi’an, China

Heavy load cargo bikeHeavy cargo bicycle in Xi’an, China

Cambodian vendor cargo bikeCargo bicycle in Cambodia

Cargo scooter beijingLoading an electric cargo scooter in Beijing, China

Cargo scooter LhasaCargo scooter in traffic in Lhasa, Tibet

cargo scooter big loadElectric cargo scooter/truck with a large volume load in Beijing, China

Cargo motorcycle tractor trailerCargo motorcycle tractor/trailer in Cambodia

Quadrennial Energy Review

On 9 January 2014 the Administration launched a “Quadrennial Energy Review” (QER) to examine “how to modernize the Nation’s energy infrastructure to promote economic competitiveness, energy security, and environmental responsibility…” You can read the Presidential Memorandum establishing the QER at the following link:

https://www.whitehouse.gov/the-press-office/2014/01/09/presidential-memorandum-establishing-quadrennial-energy-review

You can get a good overview of the goals of the QER in a brief factsheet at the following link:

https://www.whitehouse.gov/the-press-office/2015/04/21/fact-sheet-administration-announces-new-agenda-modernize-energy-infrastr

On April 21, 2015, the QER Task Force released the “first installment” of the QER report entitled “Energy Transmission, Storage, and Distribution Infrastructure.” The Task Force announcement stated:

“The first installment (QER 1.1) examines how to modernize our Nation’s energy infrastructure to promote economic competitiveness, energy security, and environmental responsibility, and is focused on energy transmission, storage, and distribution (TS&D), the networks of pipelines, wires, storage, waterways, railroads, and other facilities that form the backbone of our energy system.”

The complete QER 1.1 report or individual chapters are available at the following link:

https://energy.gov/epsa/quadrennial-energy-review-first-installment

QER 1.1 contents are listed below:

QER 1.1 contentOn January 6, 2017, the QER Task Force released the “second installment” of the QER report entitled “Transforming the Nation’s Electricity System.” The Task Force announcement stated:

“The second installment (QER 1.2) finds the electricity system is a critical and essential national asset, and it is a strategic imperative to protect and enhance the value of the electricity system through modernization and transformation. QER 1.2 analyzes trends and issues confronting the Nation’s electricity sector out to 2040, examining the entire electricity system from generation to end use, and within the context of three overarching national goals: (1) enhance economic competitiveness; (2) promote environmental responsibility; and (3) provide for the Nation’s security.

The report provides 76 recommendations that seek to enable the modernization and transformation of the electricity system. Undertaken in conjunction with state and local governments, policymakers, industry, and other stakeholders, the recommendations provide the building blocks for longer-term, planned changes and activities.”

The complete QER 1.2 report or individual chapters are available at the following link:

https://energy.gov/epsa/quadrennial-energy-review-second-installment

QER 1.2 contents are listed below:

QER 1.2 contentI hope you take time to explore the QERs. I think the Task Force has collected a great deal of actionable information in the two reports. Converting this information into concrete actions will be a matter for the next Administration.

Airbus Delivers its 10,000th Aircraft

Airbus was founded on 18 December 1970 and delivered its first aircraft, an A300B2, to Air France on 10 May 1974. This was the world’s first twin-engine, wide body (two aisles) commercial airliner, beating Boeing’s 767, which was not introduced into commercial service until September 1982. The A300 was followed in the early 1980s by a shorter derivative, the A310, and then, later that decade, by the single-aisle A320. The A320 competed directly with the single-aisle Boeing 737 and developed into a very successful family of single-aisle commercial airliners: A318, A319, A320 and A321.

On 14 October 2016, Airbus announced the delivery of its 10,000th aircraft, which was an A350-900 destined for service with Singapore Airlines.

EVE-1236Source: Airbus

In their announcement, Airbus noted:

“The 10,000th Airbus delivery comes as the manufacturer achieves its highest level of production ever and is on track to deliver at least 650 aircraft this year from its extensive product line. These range from 100 to over 600 seats and efficiently meet every airline requirement, from high frequency short haul operations to the world’s longest intercontinental flights.”

You can read the complete Airbus press release at the following link:

http://www.airbus.com/presscentre/pressreleases/press-release-detail/detail/-9b32c4364a/

As noted previously, Airbus beat Boeing to the market for twinjet, wide-body commercial airliners, which are the dominant airliner type on international and high-density routes today. Airbus also was an early adopter of fly-by-wire flight controls and a “glass cockpit”, which they first introduced in the A320 family.

In October 2007, the ultra-large A380 entered service, taking the honors from the venerable Boeing 747 as the largest commercial airliner.   Rather than compete head-to-head with the A380, Boeing opted for stretching its 777 and developing a smaller, more advanced and more efficient, all-composite new airliner, the 787, which was introduced in airline service 2011.

Airbus countered with the A350 XWB in 2013. This is the first Airbus with fuselage and wing structures made primarily of carbon fiber composite material, similar to the Boeing 787.

The current Airbus product line comprises a total of 16 models in four aircraft families: A320 (single aisle), A330 (two aisle wide body), A350 XWB (two aisle wide body) and A380 (twin deck, two aisle wide body). The following table summarizes Airbus commercial jet orders, deliveries and operational status as of 30 November 2016.

Airbus orders* Includes all models in this family. Source: https://en.wikipedia.org/wiki/Airbus

Boeing is the primary competitor to Airbus. Boeing’s first commercial jet airliner, the 707, began commercial service Pan American World Airways on 26 October 1958. The current Boeing product line comprises five airplane families: 737 (single-aisle), 747 (twin deck, two aisle wide body), 767 (wide body, freighter only), 777 (two aisle wide body) and 787 (two aisle wide body).

The following table summarizes Boeing’s commercial jet orders, deliveries and operational status as of 30 June 2016. In that table, note that the Boeing 717 started life in 1965 as the Douglas DC-9, which in 1980 became the McDonnell-Douglas MD-80 (series) / MD-90 (series) before Boeing acquired McDonnell-Douglas in 1997. Then the latest version, the MD-95, became the Boeing 717.

Boeing commercial order status 30Jun2016

Source: https://en.wikipedia.org/wiki/Boeing_Commercial_Airplanes

Boeing’s official sales projections for 2016 are for 740 – 745 aircraft. Industry reports suggest a lower sales total is more likely because of weak worldwide sales of wide body aircraft.

Not including the earliest Boeing models (707, 720, 727) or the Douglas DC-9 derived 717, here’s how the modern competition stacks up between Airbus and Boeing.

Single-aisle twinjet:

  • 12,805 Airbus A320 family (A318, A319, A320 and A321)
  • 14,527 Boeing 737 and 757

Two-aisle twinjet:

  • 3,260 Airbus A300, A310, A330 and A350
  • 3,912 Boeing 767, 777 and 787

Twin aisle four jet heavy:

  • 696 Airbus A340 and A380
  • 1,543 Boeing 747

These simple metrics show how close the competition is between Airbus and Boeing. It will be interesting to see how these large airframe manufacturers fare in the next decade as they face more international competition, primarily at the lower end of their product range: the single-aisle twinjets. Former regional jet manufacturers Bombardier (Canada) and Embraer (Brazil) are now offering larger aircraft that can compete effectively in some markets. For example, the new Bombardier C Series is optimized for the 100 – 150 market segment. The Embraer E170/175/190/195 families offer capacities from 70 to 124 seats, and range up to 3,943 km (2,450 miles).  Other new manufacturers soon will be entering this market segment, including Russia’s Sukhoi Superjet 100 with about 108 seats, the Chinese Comac C919 with up to 168 seats, and Japan’s Mitsubishi Regional Jet with 70 – 80 seats.

At the upper end of the market, demand for four jet heavy aircraft is dwindling. Boeing is reducing the production rate of its 747-8, and some airlines are planning to not renew their leases on A380s currently in operation.

It will be interesting to watch how Airbus and Boeing respond to this increasing competition and to increasing pressure for controlling aircraft engine emissions after the Paris Agreement became effective in November 2016.

Improving Heavy Tractor-Trailer Aerodynamics

My recent road trip to the Black Hills included long transit days each way on Interstate 90 through southern Minnesota and South Dakota. One thing I noticed was that many of the heavy tractor-trailers on this high speed route had streamlined tractors and / or trailers with a variety of aerodynamic devices that appeared useful for reducing drag and fuel consumption. In addition, there were quite a few trucks hauling double trailers.

The trucking industry’s ongoing efforts to improve heavy freight vehicle performance and economics was aided in 2004 by the creation of the SmartWay Transport Partnership, which is administered by the Environmental Protection Agency (EPA). SmartWay® is a voluntarily program for achieving improved fuel efficiency and reducing the environmental impacts from freight transport. The goal is, “to move more freight, more mile, with lower emissions and less energy.”

EPA SmartWay

SmartWay® is promoting the following strategies to help the heavy trucking industry meet this goal:

  • Idle reduction
  • Speed control
  • Driver training
  • Aerodynamics
  • Tire technologies
  • Lubricants
  • Hybrid power trains
  • Improved freight logistics
  • Vehicle weight reduction
  • Intermodal freight capability
  • Alternative fuels
  • Long combination vehicles (LVCs, such as double trailers)

The SmartWay® website is at the following link:

https://www.epa.gov/smartway

You’ll find an interesting Fall 2014 presentation on the SmartWay Transport Partnership at the following link:

http://www.mmta.com/document_upload/SmartWay%20and%20Truck%20Drivers.pdf

Key points from this presentation include the following:

  • Freight transportation is a cornerstone of the U.S. economy. As of 2012, U.S. businesses spent $1 trillion to move $12 trillion worth of goods (8.5% of GDP).
  • Freight accounts for 9% of all U.S. greenhouse gas (GHG) emissions, and trucking is the dominant mode. (Note: There were about 2 million tractor-trailers in active service in the U.S. in 2011).
  • A truck or trailer fitted out with all the essential efficiency features can be sold as a SmartWay® “designated” model. A “designated” tractor-trailer combo can be as much as 20% more fuel-efficient than the comparable standard model.

In May 2012, the Canadian Center for Surface Transportation Technology (CSTT) issued technical report CSTT-HVC-TR-205, which is entitled, “Review of Aerodynamic Drag Reduction Devices for Heavy Trucks and Buses.” In Table 2 of this report, CSTT provides the following illustrative example of the relative power consumption of aerodynamic drag and rolling / accessory drag as a function of vehicle speed.

CSTT truck power consumption tableRelative contributions to total vehicle drag. Source: CSTT

In this example, rolling / accessory drag dominates at lower speeds typical of urban driving. At 50 mph (80 kph) aerodynamic drag and rolling / accessory drag are approximately equal. At higher speeds, aerodynamic drag dominates power consumption. The speed limit on I-90 in South Dakota typically is 80 mph (129 kph). At this speed the aero drag contribution is even higher than shown in the above table

Key points from this CSTT report include the following:

  • For tractor-trailers, pressure drag is the dominant component of vehicle drag, due primarily to the large surface area facing the main flow direction and the large, low-pressure wake resulting from the bluntness of the back end of the vehicle.
  • Aero-tractor models can reduce pressure drag by about 30% over the boxy classic style tractor.
  • Friction drag occurring along the sides and top of tractor-trailers makes only a small contribution to total drag (10% or less), so these areas are not strong candidates for drag-reduction technologies.
  • The gap between the tractor and the trailer has a significant effect on total drag, particularly if the gap is large. Eliminating the gap entirely could reduce total drag by about 7%.
  • Side skirts or underbody boxes prevent airflow from entering the under-trailer region. These types of aero devices could reduce drag by 10 – 15%.
  • Wind-tunnel and road tests have demonstrated that a “boat tail” with a length of 24 – 32 inches is optimal for reducing drag due to the turbulent low-pressure region behind the trailer
  • Adding a second trailer to form an LCV, and thus doubling the freight capacity, results in a very modest increase in drag coefficient (as low as about 10%) when compared to a single trailer vehicle.
  • In cold Canadian climates, the aerodynamic drag in winter can be nearly 20% greater than at standard conditions, due to the ambient air density. For highway tractor-trailers, this results in about a 10% increase in fuel consumption from drag when compared to the reference temperature, further emphasizing the importance of aerodynamic drag reduction strategies for the Canadian climate.

You can read an executive summary of this CSTT report at the following link:

https://www.tc.gc.ca/eng/programs/environment-etv-menu-eng-2939.html

You can download the complete 100-page report here:

https://www.tc.gc.ca/media/documents/programs/AERODYNAMICS_REPORT-MAY_2012.pdf

The 2012 CSTT report includes a note that Mercedes had introduced a concept trailer that is reported to provide an 18% reduction in drag for a full European tractor-trailer combination.

Mercedes-aero-trailer-4 Source: Mercedes

You can view a short 2012 YouTube video on a similar Mercedes aero tractor-trailer at the following link:

https://www.youtube.com/watch?v=I1Sq2Q8YEYw

The U.S. firm STEMCO offers two aero kits for improving conventional tractor-trailer aerodynamics:

  • TrailerTail®, which is installed at the back of the trailer, reduces the magnitude of the turbulent low-pressure area that forms behind the trailer at high speeds.
  • EcoSkirt®, which is installed under the trailer, reduces aerodynamic drag under the trailer where air hits the trailer’s rear axles. The side fairings streamline and guide the air around the sides and to the back of the trailer.

Both of these aerodynamic devices are shown in the following figure.     This was a tractor-trailer configuration that I saw frequently on I-90.

Stemco 1794Source: STEMCO

STEMCO allocates the primary sources of tractor-trailer aerodynamic drag as shown in the following figure.

Stemco contributions to semi aero dragSource: STEMCO

STEMCO claims the following benefits from their aero kits:

“TrailerTail® fuel savings complement other aerodynamic technologies. A TrailerTail® reduces aerodynamic drag by over 12% equating to over 5% fuel efficiency improvement at 65 mph (105 kph) and over 12% fuel efficiency improvement when combined with STEMCO’s side skirts and other minor trailer modifications.”

STEMCO TrailerTail® meets the SmartWay® advanced trailer end fairings criteria for a minimum of 5% fuel savings and the STEMCO EcoSkirt® meets the advanced trailer skirts qualifications with greater than 5% fuel savings. The payback period for these aero devices is expected to be about one year.

You’ll find more details on STEMCO’s tractor-trailer drag reduction products, including a short “Aerodynamics 101” video, at the following link:

http://www.stemco.com/aero-u/

More details on TrailerTail®, including its automatic deployment and operational use, are shown in a short video at the following link:

https://www.youtube.com/watch?v=qPrM3-CCth8

Another firm, Aerotech Caps, offers a range of aero kits for improving truck aerodynamics, including aerodynamic wheel covers, aerodynamic trailer skirts, tail fairings and vortex generators. You can see their product line at the following link:

http://www.aerotechcaps.com/index.html

Aero wheel covers

Source: Aerotech Caps

Aerotech Caps claims that its aerodynamic wheel covers deliver about 2.4% increased miles per gallon when installed on rear tractor and all trailer wheels. Payback period for this aero kit is expected to be about one year.

The future of heavy freight vehicles is likely to include increasingly aerodynamic tractor-trailers. One particularly elegant concept vehicle is shown below.

Future TruckjpgConcept aero-optimized heavy freight vehicle. Source: http://forums.fourtitude.com

In spite of all of these opportunities for improving heavy tractor-trailer aerodynamics, there always will be cases when few of these are actually practical. As evidence, I offer the following photo taken at 80 mph on I-90 in South Dakota during my recent road trip. How do you optimize that giant drag coefficient?

DSC_5401Source: Author photo