Renewables on track

 By Nicholas Newman

Today it is a rare sight to see a train steaming away from a station; usually you have to visit a tourist railway to see a historic steam train. However, less than 50 years ago, it was commonplace in Europe to see steam trains. Certainly many famous films are based on trains, especially steam trains. For instance, Murder on the Orient Express, the star of the film is the steam train. Nowadays, trains are powered by diesel or electricity. The electric powered ones are just as likely to obtain their power from a dam on the Rhine, a French nuclear power station, a Dutch wind farm or even an Italian solar farm. In addition, the trains are getting into the act of powering themselves. In London, there is a station covered in solar panels that helps power the trains that use it. Elsewhere, trains are using the power to brake to be stored in a battery for use to help the train move off again. Elsewhere, engineers are looking at powering trains using LNG, hydrogen or even on board nuclear power. However, one thing is certain, the train you see running past your office will have an interesting story to tell about how it is powered and the energy sourced…

It is increasingly rare to see a train steaming away from a station, unless it is a heritage train maintained by enthusiasts. The ‘golden’ age of steam locomotives, as featured in many famous films including, Anna Karenina, Polar Express and the classic, Murder on the Orient Express, in which the train is the star of the show, has been largely superseded by diesel and electric powered trains in Europe and North America.

In Europe today, the Eurostar 300 kph high-speed train leaving London for Brussels or Paris may be powered by either electricity from a French nuclear power station or a Polish coal power station, or even, by environmentally- friendly rail-side solar panels. Installing Solar PV panels along just this one service could, according to WSPGroup calculations , potentially save £30 million ($45.2 million) and 895,000 metric tons ( 986,568 short tons) of carbon a year for Network Rail (UK’s rail infrastructure agency). Additional savings can be achieved from regenerative braking, whereby the train uses a fraction of the power generated from a previous application of brakes, earlier on the line.

Throughout Europe, regenerative braking and batteries is proving to be an increasingly popular fuel source, for both suburban train and tram networks. For example, in the French port of Nice, conventional overhead power supply cables provide 750 V DC of power to the city’s trams. The only exceptions being the large public squares of Place Masséna and Place Garibaldi, where overhead wires would be an eyesore. Here crossing trams lower their pantograph and switch to their onboard nickel metal hydride batteries.

The past half-century has seen immense advances in trains’ productivity and efficiency with the successive adoption of diesel, diesel-electric hybrid or electricity using locomotives. In the UK, regional rail operator, Great Western plans to introduce bi-mode Intercity Expresses (IEPs) able to operate beyond the existing electrified network using installed diesel engines. Today, in response to climate change, rail engineers are experimenting with alternative propelling technologies such as lithium batteries, hydrogen fuel cells, flywheels and natural gas.

Does Diesel have a future?

Ever since Europe and North America began to phase out steam trains in the 1950s, diesel locomotives have dominated passenger and freight services. Diesel powered freight trains represented a significant breakthrough in fuel efficiency, being able to move a ton of freight an average of 457 mi (735 km), on a single gallon of fuel. According to the Federal Railroad Administration, freight railways are between nearly two and five times more fuel-efficient and considerably cheaper than trucks or lorries. The savings can be considerable. For example it costs around £160,000 ($241,297) a year in fuel, to operate a daily 600-mi (966-km) passenger diesel train service, according to “Battery Powered Trains,” a report by Britain’s Transport Research Laboratory issued in January 2013.

There are currently two different types of diesel locomotives. The first are diesel-mechanical locomotives using engines similar to diesel cars and trucks, which are employed as switchers or shunters in goods-yards or ports. The second type, is the diesel-electric locomotive, which uses a combination of diesel and electric engines to power a hybrid train. In this case, the diesel engine generates power for the electric motors to propel the train and provide electricity for the rest of the train. Since the 1970’s such hybrid-diesel electric locomotives have been the motive power of choice, for both passenger and freight trains such as Australia’s XPT intercity train linking Adelaide with Sydney and Melbourne. It uses a Paxman VP185 12-cylinder, turbo-charged diesel electric engine boasting 2000 horsepower.

Although cleaner than yesterday’s steam trains, increasingly strict environmental regulations are behind efforts to further clean up diesel trains. Manufacturers such as GE and ABB have innovations that make diesel trains quieter, cleaner and more fuel-efficient. For instance, GE Transportation’s, latest series of fuel-efficient heavy-haul Evolution Series Locomotives, have cut emissions by more than 70 percent compared with their 2005-based technology and can meet the latest U.S. EPA Tier 3 and EU IIIa targets. Customers have also benefited, to the tune “of more than $1.5 billion in infrastructure and operational costs,” says a GE representative. Another recent innovation is the Green Goat locomotive, a type of combined hybrid able to switch power between a small diesel engine and a large bank of rechargeable batteries. Green Goat locomotives are ideal for city services, where trains tend to be idle and where local populations, are sensitive to noise and pollution.

Solar power is no longer just for toy trains or university research. Since 2009, the railway industry has taken an active interest in exploiting solar power to provide energy for its lighting, customer information signage, signals and stations

Providing the spark behind train travel

Increasingly throughout Europe, it has become commonplace for trains to be powered by electricity. Electrification of railways is not a new concept. Mainline electric locomotives have been employed in Europe since the 1890s. Today, electric high-speed trains, such as the French TGV , draw their power from an overhead wire while some London commuter services are powered from an electrified third rail.

Although initial costs of electrification are high, electric trains are cheaper to run. As Secretary of State for Transport, Justine Greening said in a debate in the House of Commons in June 2012, “the comparative fuel cost per mile is 47p (71 cents) for diesel trains as compared with 26p (39 cents) for electric ones, whilst track wear and tear per mile is 9.8p (15 cents) for diesel and 8.5p (13 cents) for electric.” Electric trains have other advantages over diesel being, lighter, faster, cleaner, easier to maintain and longer potentially longer in length. The main disadvantage of electric trains is the initial capital cost of electrification. For example, the ongoing wiring up of the 235 mi (378 km) of heavily congested main line railway linking London with Bristol and Cardiff cost £2.5bn-£2.8bn but was probably worth it since “rail electrification hugely benefits passengers by enabling faster, more reliable train services,” said Britain’s rail minister Simon Burns. The electricity for this and the other 2,000 mi (3,219 km) of electrification projects planned by infrastructure owner Network Rail, will come from French nuclear power company EDF, Network Rail announced in January 2013.

Battery-powered trains are currently being tested to fill the gaps, between the mainline electrified sections of the UK’s rail network and branch lines, which are less likely to be electrified. During January 2015, a train with lithium iron magnesium batteries was tested on a branch line linking Harwich with Manningtree station in Essex, UK. On successful completion of final testing it is expected that purpose built trains using such batteries will be ordered. Network Rail principal engineer, James Ambrose, said such trains “ would contribute to the company’s goal of reducing its environmental impact, improving sustainability and reducing the cost of running the railway by 20per cent over the next five years.”

For countries without an extensive electrified rail network, including North America, locomotives fueled by LNG (liquefied natural gas) could be an option. Natural gas, even after processing into liquefied natural gas, is significantly lower cost per unit of energy, than diesel. However, before the widespread adoption of LNG becomes possible, three pre-conditions have to be met: development of the required engine and fuel tender technology, the provision of fuel infrastructure and a supportive regulatory framework. In terms of current fuel- tender design, “it’s too early to tell,” says BNSF Director Operations Support Mike Swaney.

Solar Power Gives a Boost to High Speed Trains

Solar power is no longer just for toy trains or university research. Since 2009, the railway industry has taken an active interest in exploiting solar power to provide energy for its lighting, customer information signage, signals and stations. In London for example,Blackfriars mainline station is using 4,400 solar photovoltaic (PV) panels, to generate an estimated 900,000kWh of electricity, or half of the station’s energy a year, while simultaneously reducing the station’s CO2 emissions by an estimated 490 tonnes reports Railtrack.

In Belgium, railway infrastructure agency Infrabel working with renewable energy company Enfinity, constructed a 22-mi (3.6-km) long, solar-powered tunnel enclosure over its main surface high- speed line connecting Antwerp with Amsterdam. The above-ground tunnel enclosure is designed to protect the high-speed line from falling trees blocking the line. The 16,000 solar panels installed on the tunnel roof have 3.3GWH of generating capacity, sufficient to power 4,000 train journeys a year. “For train operators, it is the perfect way to cut their carbon footprints,” said Bart Van Renterghem, UK head of Belgian renewable energy company Enfinity, which installed the panels on behalf of Infrabel.

Burning Hydrogen

Unlike solar-powered trains, hydrogen-powered trains are still under development. Also known as “hydrail,” they are based on the concept of converting the chemical energy stored in hydrogen into mechanical energy. Two main approaches are being investigated. The first involves burning hydrogen in hydrogen internal combustion engines and the second is, by reacting hydrogen with oxygen, in a fuel cell to run electric motors. However, a hybrid locomotive is in development. In 2014 Alstom, the French train builder signed a contract with German regional transport operators to build two prototype trains using modified Coradia Lint multiple units. These new trains, expected to be operational as early as 2018, will use a combination of hydrogen fuel cells, batteries and energy storage systems to replace a roof-mounted diesel power pack, giving equivalent performance to an electric multiple-unit. In the meantime, hybrid trains or trams incorporating traditional engines, using regenerative braking technology could provide a bridging solution on the way towards hydrogen- powered trains.

Once the technology is proven, hydrail could become a serious contender since, “the primary advantage of hydrail is that it runs on ordinary track”, explains Stan Thompson, chairman of the Hydrogen Economy Advancement Team (HEAT). Rural lines in Europe and the un-electrified lines of North America could provide a sufficiently large market for this technology.

As for the Future

Anticipated rising energy costs together with stricter environmental controls are driving diverse technological innovations and locomotive development. One recent trend is the adoption of hybridization using different combinations of motive power designed to meet specific market needs ranging from hi-speed mainline services, suburban and city rail and tram services, industrial and mining trains. One thing is certain, the train passing you by has many stories to tell, both of how it is powered and where its energy comes from.

about the author
Nicholas Newman
Freelance energy journalist and copywriter who regularly writes for AFRELEC, Economist, Energy World, EER, Petroleum Review, PGJ, E&P, Oil Review Africa, Oil Review Middle East. Shale Gas Guide.