A. U.S. Department of Energy laboratory managed by The University of Chicago 

# Economic Analysis of Commercial Idling Reduction Technologies
**Which idling reduction system is most economical for truck owners?** Linda Gaines and Danilo Santini – Center for Transportation Research Argonne National Laboratory

System Idling (baseline) Heat recovery Automatic start/stop Cab/bunk heater Evaporative cooler Air conditioner Auxiliary power unit (APU) or generator set Electrified parking space (EPS) (single system) e EPS (dual system) f 

# Cab Comfort Technologies

Services

All Heating All, intermittently

Heating (cab)

Cooling Cooling

All
All
All Fuel Use (gal/hour) 0.8 Negligible 0.8 if on, 0 if off 0.04 0.015 0.15 0.2
0
0 Installed Cost ($) 0 600 1200 1300 1800 4000 d 8000
10
2500 Maintenance ($/yr) See note a

0 See note b

110 c 100 200 c 400
0
100 Charge ($/hr)

0 0 0 0 0 0 0
2 g
1

a 

### Defaults for idling maintenance: $150/30,000 miles for oil change, $10,000 at 500,000 miles for overhaul. b 

### Same as idling, multiplied by the fraction of time the engine is on. Possible additional contribution from engine turning on repeatedly.
c 

### American Transportation Research Institute, Idle Reduction Technology: Fleet Preferences Survey (February 2006) d 

### No battery replacement included for battery-powered air conditioner.
e 

### A heating, cooling, and ventilation unit above each parking space is connected to a window-mounted service module via a flexible, reinforced, concentric hose that also delivers communications and entertainment packages. f 

### On-board equipment powered by extension cord to wayside electrical pedestal. g 

### $2.18 per hour retail; $1.85 per hour fleet discount. (Ref: Brass, Larisa: IdleAire's promise: New financing could help put a Knoxville company in truck stops across America , Knox News (February 20, 2006) (accessed June 2, 2006).)



# Payback Time vs. Fuel Price, by Device, Used 2,000 Hours per Year

Total Cost for Six Years of Operation vs. Idling Time @ $3/gallon

40

35

30

25

20

15

10

5

0 500 1000 Hours per Year$(1000)

1500 2000 2500 0 Idling Heat recovery Heater only Heater plus air conditioner APU Dual system EPS Single system EPS 3 4 5 6 7 8 10

2
1

1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 Diesel price ($/gallon)Payback time (years)

0 9

a Actual amount of time heater can be used varies by location Increasing level of cab comfort Heater only (used 50% of year) a Heater plus evaporative cooler Heater plus air conditioner APU Top-of-line APU ($10,000) Dual system EPS



# Conclusions 1. Fuel-fired heaters are the least expensive means of providing heating for trucks that would otherwise idle overnight. The worksheet should be used to confirm whether an auxiliary air conditioning unit is also economical. 2. On-board IR systems (including dual-system EPS) are the least expensive means of providing full cab comfort services, in the event of high annual use hours and long retention of the systems (six years illustrated here).3. For a low-annual-use case, a single-system EPS (an offboard system) is the least expensive full-service choice when fuel prices are high. 

# Overview Several factors have combined to create a surge of interest in idling reduction (IR). One is the increasing number of states and localities that have instituted restrictions on idling for trucks and other heavy vehicles. Extended idling by commercial trucks, both overnight and during the workday, also costs truck owners billions of dollars annually and uses a significant amount of our petroleum resources. Increased interest in IR has led to rapid growth in the number of equipment suppliers and the types of IR devices available. Although many suppliers have joined together to educate potential customers and government agencies, individual manufacturers often provide conflicting claims about the comparative financial merits of different devices. That makes it difficult for truck owners to choose the right equipment for their needs.

Note: Unknowns such as quality of service, IR device reliability, and variations in truck owner and driver preferences and in the need for services mean that the findings are informative, but not conclusive. Each option must be evaluated on its merits, as applicable to the owner's needs, before a purchase decision can be reached. 

# Approach This effort considers the types of devices available and provides a worksheet that allows a truck owner to estimate the costs, savings, and payback for each system. The truck owner must supply several inputs (particularly idling profile) to determine what the payback period is for each device and what the cash flow looks like as a function of time for typical inputs. Although it was developed with trucks in mind, the worksheet could be used for buses and other types of heavy vehicles as well. This figure shows how payback time varies with fuel price for a range of device costs (from $1,300 to $10,000) for a long-haul truck that idles for 2,000 hours per year (40 h/week 50 weeks). At $3 per gallon for diesel fuel, devices costing $7,000 or less pay back their investment in the two-years-or-less timeframe that many truck owners have cited as a goal, and even devices costing $10,000 pay back in under three years. The same analysis can be performed for day cabs, but because these trucks idle fewer hours per day, only a much smaller investment will pay back in an acceptable period. Payback for the single-system electrified parking space (EPS) is immediate at fuel prices over $2.50 per gallon, but the figure below shows that other criteria are also important.

This figure compares total cost to the truck owner over six years for different IR systems, assuming the current diesel price of $3 per gallon. This graph shows that, for the technology options that supply both heating and cooling, the relative ranking changes as a function of hours of idling eliminated. It is also true that diesel fuel price and length of ownership can change these rankings. Expensive fuel and long vehicle ownership favor on-board options and the dual-system EPS. Also note that the heater and heat recovery options are only needed in winter, and heat recovery only has capacity for up to four hours per day.