By Noel T. Braymer
There are major changes coming in the near future to transportation, and this will impact rail passenger service as well. All forms of transportation are under pressure to save money, be more energy efficient and run more cleanly. Autos, truck and bus builders are looking for solutions to these problems. We may find that the solutions these other forms of transportation use could have an impact to the railroads much like when GM introduced the diesel locomotive in the 1930’s.
An example of what is coming is from a start up electric bus company named Proterra . It has built a prototype electric bus with enough range to run an entire day in service on a single charge. A major factor for this range is the fact that the bus is built largely with carbon fiber instead of steel. Carbon fiber is much stronger than steel, lighter than aluminum and doesn’t rust. Because of its costs its use has been limited largely to military aircraft and race cars. However as production increases which brings economies of scale, the price of carbon fiber is coming down. Carbon itself is one of the most common elements in the universe. The automaker BMW has built the world’s largest carbon fiber factory in South Carolina for use in its cars. BMW in now selling a lightweight electric car built with carbon fiber. BMW has announced that in the next 10 years it will phase out all of its gasoline engine cars and build only hybrids and electric cars.
Electric batteries continue to become lighter, hold more energy and cheaper. In 2013 the International Energy Agency (IEA) predicted that for electric cars to be cost competitive with gasoline cars, the cost of the battery on a kilowatt per hour (kWh) basis would have to be no more than $300 per kWh. The IEA predicted that this would happen around 2020. In 2013 the cost of an electric car battery came in at about $500 per kWh. General Motors’ new electric car, the Bolt going on sale in the 2017 model year will have a 200 mile range on a single charge and cost around $35,000. General Motors recently announced that the price of building its battery will cost $145 per kWh in 2017. By 2022 the price for it’s battery is expected to drop to $100 kWh.
Along with cars using less energy by using electricity to travel the same distance than using traditional fuels, the cost of using renewable energy to make electricity continues to go down. The electric utilities are making plans to expand their market by encouraging more customers to drive electric cars. By 2020 we could see a major turn around beginning in the auto and truck markets and declining use of fuels. Trucking companies are also under pressure to save money and reduce emissions. To do this prototype trucks funded by Walmart with much better aerodynamics and hybrid power are being tested. Such efforts have reduced fuel consumption by half for big rig trucks. This has included hybrid turbine electric powertrain. Turbine engines are very efficient run at a constant speed, They are also very clean and produce fewer emissions than diesel engines. Combined with batteries the turbine can keep the batteries charged and gives future trucks long range and excellent fuel economy.
So how could this effect future rail passenger equipment? We could see more MU trains built with strong light weight carbon fiber bodies, run with electric batteries. As a MU the batteries could be spread out on all of the cars along with powered trucks on each car. With lighter weight and improved traction such a train would have excellent acceleration and hill climbing ability. This means shorter running times. Such trains could also have pantographs. This would allow trains to use electrified segments of railroads to save battery power and to use electrified segments to accelerate which has the greatest power consumption for a train. This would allow trains to operated on heavily used main lines under catenary, but continue service on branch lines where it isn’t economical to electrify. Money can be saved by not electrifying entire railroads which can be expensive This would insure that the battery powered trains don’t run low on power. This not only save money on catenary, but avoids complaints from residents of building catenary in their neighborhoods.
So what about the locomotive of the future, for both passenger and freight trains? As battery cost continue to decline, it will become more economical to use batteries than a diesel engine. This is particularly true as the energy density of batteries improve. A battery powered locomotive would have lower operating costs and lower maintenance costs was well. How would an electric locomotive get charged on a long trip? One way would be to have short segments of catenary to allow trains to charge on the go. The best places for this would be at steep grades and where trains are most likely to accelerate. One major advantage of using batteries is that they can be charged using power from regenerating braking on the trains.
In some cases it might be better to use hybrid locomotives. This too can use turbine engines which burn very cleanly and efficiently to keep the batteries charged on locomotives. What fuels can we use to get the cleanest running with a turbine? Fuels made from algae, often called pond scum, have been used and proven to work running diesel and turbine engines. The problem so far is these experimental fuels cost more than conventional fuels. Progress is being made to lower the cost of algae fuels, so it may only be a matter of time before we see much greater use of these fuel. We may first see blends of both algae and conventional fuels. This would create a much cleaner burning fuel. Algae may replace ethanol in fuel as a better alternative to reduce emissions. This is particularly needed in the short run for diesel fuel.
What we can look forward too in the future on trains, is even cleaner, more economical and more reliable passenger and freight trains in the next 5 to 10 years.