Railroad Trains for the Soul - Battery-Electric Locomotives
This may be a broad topic in contemporary railroading, but in celebration of Earth Day 2022, let’s talk about zero-emissions, battery-electric locomotives that have already been built as well as those that are currently in the design process. The two largest North American diesel builders, Progress Rail/Electro-Motive Diesel and Wabtec/GE Transportation, are offering battery-powered locomotives for not only yard switching but even for mainline freight duty. During the 19th century, some of the earliest known battery-electric trains were built primarily for mining areas where smoke emissions and fire ignition are strictly prohibited. They were also used to bypass the installation of an overhead wire that would otherwise power regular electric locomotives. In the 1920s, the American Locomotive Company and General Electric engineered what was referred to as a tri-power locomotive for the New York Central Railroad. It had three different propulsion sources: onboard batteries, a diesel generator, and a third-rail connection. This model was designed to comply with New York’s smoke abatement laws while easily maneuvering through some areas that lacked the electrical third rails. To recharge the batteries, only the diesel engine could do that activity, not the third rail.
In 2002, GE constructed its first GEVO-powered ES44AC diesel locomotive prototype (numbered 2005) as part of the builder’s newly introduced Evolution Series. Five years later, it was modified and renumbered into what became the Evolution Hybrid #2010. The purpose was to promote energy-savings technology by using a series of batteries that can receive energy when dynamic braking is activated. In this case, the term is technically called regenerative braking where some of the power generated by the locomotive’s traction motors can be stored into the batteries rather than just being dissipated as heat. In 2013, GE built an experimental dual-fuel ES44 demonstrator that could run on either regular diesel fuel or the cleaner natural gas. Numbered as GECX 3000, the locomotive featured the NextFuel retrofit kit that can fit into existing GEVO-engined models, be they Tier 2 or Tier 3 emissions-compliant.
When the BNSF Railway gained interest in battery-electric technology, GE Transportation (now merged with Westinghouse Air Brake Technologies in 2019) decided to rebuild the NextFuel demonstrator into what is considered to be the world’s first practical mainline locomotive powered entirely by batteries; it was named FLXdrive. In an effort to produce 4,400 horsepower (equal to about 2,400 kilowatt hours), the unit required approximately 20,000 lithium-ion battery cells. While the first half of the locomotive appears to be the same, the other half was completely rebuilt with a full-width body to house the complex zero-emissions system. As a similar case to the GE Evolution Hybrid, the Wabtec FLXdrive has a regenerative/dynamic braking system to recharge the batteries while on the road, although it can also be plugged into a stationary source. Because it was requested by the BNSF, the six-axle FLXdrive was configured with the A1A-A1A wheel arrangement, which has only four traction motors instead of six. Like many recent freight locomotives, the demo unit has AC motors that receive alternating current from the inverters where the battery-supplied direct current is fed.
While it is possible to operate the FLXdrive as a single unit, it is currently intended to be connected with a conventional diesel locomotive for best results. For instance, one battery locomotive coupled to two diesels means that the train can produce 33 percent fewer emissions than a three-diesel consist. By the time the FLXdrive was sent to California for testing, its formal designation was now named BEL44C4D. Although the demonstrator has approximately the same frame length (74 feet, 6 inches) as in a GE Tier 4 ET44C4 diesel, it is expected that a production version of the FLXdrive will require a substantially longer frame. This will possibly be a similar size to the 76-feet-long AC6000CW as well as the ES44ACi and DCi models for Australia. As a side note, the extra frame length for those export units was used to accommodate an extended cooling system that would endure the harsh desert environments in Australia. Because of the increase in length, the production FLXdrive series may probably include a six-motor C-C model, which would certainly be named “BEL44AC”, in addition to the four-motor BEL44C4.
Now let's move on to Progress Rail’s own line of battery-electric locomotives: the Joule. In 2009, Norfolk Southern’s Juniata Shops rebuilt a former Penn Central EMD GP38 into a unique battery-powered switcher, named the BP4 and numbered 999. More than a decade later, Electro-Motive’s first Joule model was completed and sold to a Brazilian mining company; the six-axle locomotive has 1.9 megawatt hours of energy storage and is designated as BE1.9C. Another model, the BE2.4C (rated at 2.4 megawatt hours), will be delivered to the Pacific Harbor Lines, which is anticipated to be the first American user of the EMD battery locomotive. The third variant is by far the most powerful type to be built: the BE14.5BB. First ordered by an Australian mining railroad, Fortescue Metals Group (FMG), this locomotive will be rated at 14.5 megawatt hours and have eight axles housed in four trucks as what the BB designates. Although the BE1.9 and 2.4 switcher models will have hood-unit bodies, the mainline-duty BE14.5 must have a full-width body to sufficiently provide space for larger energy capacity.
As of this blog post, four Australian railroads have placed orders for battery-electric locomotives from Progress Rail and/or Wabtec. Back in North America, Union Pacific is interested in both the Joule and FLXdrive units while Canadian National is choosing only Wabtec. Battery locomotives can be used for both switching and freight duties, but it is not very likely that there will be a battery-powered passenger locomotive at this time. On many modern passenger diesels, it generally takes a lot of energy to produce head-end power (HEP) for the coaches, which is one possible reason. However, some of the most recent locomotives such as the Electro-Motive F125 and the Siemens Charger feature regenerative braking that can produce some extra energy for the HEP system and can even blend with the standard air brake system when applied. We hope the battery locomotives will be successful in terms of their energy efficiency, even though it is currently unlikely that they can replace a lot of diesels. With the most advanced technology available, both the Progress Rail Joule and the Wabtec FLXdrive models will be the most eco-friendly locomotives in North America and eventually around the world. Keep going green this year!
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GE Wabtec 3000 departs Erie
Wabtec's BEL FLX Drive locomotive returns to Erie. What next?