Energy Recovering Using Regenerative Braking in Diesel–Electric Passenger Trains: Economical and Technical Analysis of Fuel Savings and GHG Emission Reductions

Abstract

Rail transport, specifically diesel–electric trains, faces fundamental challenges in reducing fuel consumption to improve financial performance and reduce GHG emissions. One solution to improve energy efficiency is the electric brake regenerative technique. This technique was first applied on electric trains several years ago, but it is still considered to improve diesel–electric trains efficiency. Numerous parameters influence the detailed estimation of brake regenerative technique performance, which makes this process particularly difficult. This paper proposes a simplified energetic approach for a diesel–electric train with different storage systems to assess these performances. The feasibility and profitability of using a brake regenerative system depend on the quantity of energy that can be recuperated and stored during the train’s full and partial stop. Based on a simplified energetic calculation and cost estimation, we present a comprehensive and realistic calculation to evaluate ROI, net annual revenues, and GHG emission reduction. The feasibility of the solution is studied for different train journeys, and the most significant parameters affecting the impact of using this technique are identified. In addition, we study the influence of electric storage devices and low temperatures. The proposed method is validated using experimental results available in the literature showing that this technique resulted in annual energy savings of 3400 MWh for 34 trains, worth USD 425,000 in fuel savings.

An Estimation of the Energy Savings of a Mainline Diesel Locomotive Equipped with an Energy Storage Device

“…obtained for a specific type of diesel locomotive under specific operating conditio makes it impossible to extend them to other conditions, and therefore, there is a new studies on specific types of locomotive, train, and route. To determine the e ness of the use of energy storage on rolling stock, indicators characterizing the operating a serial rolling stock without energy storage and a hypothetical mod rolling stock with energy storage are compared [10,23]. As a rule, fuel consum taken as an indicator.…”

“…Ref. [23] provides data on the reduction in energy consumption by a passenger diesel locomotive for various operating conditions. The reduction in energy consumption is 47.52% of the total energy consumption.…”

Methodology for the Estimation of Electrical Power Consumed by Locomotives on Undocumented Railroad Tracks

“…Finally, the potential electric energy that can be generated with the locomotive at time t can be estimated as shown in (9), which corresponds to the integral of the negative values of P(t) multiplied by two efficiencies and one factor. In (9), η gen is the efficiency of the system that receives the energy generated by motors, and AF is the availability factor and represents the percentage of the locomotive braking mechanical power (i.e., P(t):P(t) < 0 W) that can be used by the regenerative braking system, which may be between 20% and 30% [30]. For example, in a diesel locomotive with a battery bank, η gen would be defined as η gen = η c • η b , where η c and η b are the efficiencies of the power converters and the battery bank.…”

Experimental Underperformance Detection of a Fixed-Speed Diesel–Electric Generator Based on Exhaust Gas Emissions

“…Conversely, an engine may be operating at low RPMs without necessarily underperforming. This could be intentional during a time of load transition, for example, onboard ships or in rail transport, when the diesel-electric generators operate under low load (≤30%) but for a determined time (less than 30 min) [6][7][8][9]. According to the Caterpillar manufacturer, underperformance occurs when the diesel generator operates under low load (≤30%) for an extended period (over 30 min) and frequently.…”