Based on a recent report to the , it appears that the cost of bringing an old locomotive up to current standards is roughly equivalent to the cost of converting an old locomotive from diesel-electric to battery powered electric. While an emissions abatement upgrade will improve fuel economy through the application of newer technology, a battery retrofit can eliminate all direct emissions and fuel consumption. Based on a current off-road diesel price of $3 per gallon and an estimated fuel consumption of 50,000 gallons per year, a battery retrofit should offer a payback period in the three to four year range. In comparison, the payback period for an emissions abatement upgrade will be closer to ten years. The long-term revenue potential of retrofitting a portion of the switcher fleet to run on batteries isn't a company maker, but it's a darned good start.