Heavy Hybrid Vehicles

electric haul truck

Heavy vehicles

Hybrid power trains are used for diesel-electric or turbo-electric railway locomotives, buses, heavy goods vehicles, mobile hydraulic machinery, and ships. Typically some form of heat engine (usually diesel) drives an electric generator or hydraulic pump which powers one or more electric or hydraulic motors. There are advantages in distributing power through wires or pipes rather than mechanical elements especially when multiple drives—e.g. driven wheels or propellers—are required. There is power lost in the double conversion from typically diesel fuel to electricity to power an electric or hydraulic motor. With large vehicles the advantages often outweigh the disadvantages especially as the conversion losses typically decrease with size. With the exception of non nuclear submarines, presently there is no or relatively little energy storage capacity on most heavy vehicles, e.g. auxiliary batteries and hydraulic accumulators—this is changing.

Rail transport  Hybrid train

hybrid electric train

Europe
An example of a typical "hybrid" is the new Autorail à grande capacité (AGC or high-capacity rail-car) built by the Canadian company Bombardier for service in France. This has dual mode (diesel and electric motors) and dual voltage capabilities (1500 and 25000 V) allowing it to be used on many different rail systems.

China
The First Hybrid Evaluating prototype locomotive was designed and contracted by railway research center MATRAI in 1999 and the sample was ready in 2000. it was a G12 locomotive that was converted to hybrid by using a 200KW diesel generator and batteries and also was equipped with 2 AC traction motors (out of 4) retrofited in the cover of the DC traction motors.

Japan
The first operational prototype of a hybrid train engine with significant energy storage and energy regeneration capability was introduced in Japan as the KiHa E200. It utilizes battery packs of lithium ion batteries mounted on the roof to store recovered energy.

North America
In the U.S., General Electric introduced a prototype railroad engine with their "Ecomagination" technology in 2007. They store energy in a large set of sodium nickel chloride (Na-NiCl2) batteries to capture and store energy normally dissipated during dynamic braking or coasting downhill. They expect at least a 10% reduction in fuel use with this system and are now spending about $2 billion a year on hybrid research.

Variants of the typical diesel electric locomotive include the Green Goat (GG) and Green Kid (GK) switching/yard engines built by Canada's Railpower Technologies. They utilize a large set of heavy duty long life (~10 yr) rechargeable lead acid (Pba) batteries and 1000 to 2000 HP electric motors as the primary motive sources and a new clean burning diesel generator (~160 Hp) for recharging the batteries that is used only as needed. No power or fuel are wasted for idling—typically 60–85% of the time for these type locomotives. It is unclear if dynamic braking power is recaptured for reuse; but in principle it should be easily utilized.

Since these engines typical need extra weight for traction purposes anyway the battery pack's weight is a negligible penalty. In addition the diesel generator and battery package are normally built on an existing "retired" "yard" locomotive's frame for significant additional cost savings. The existing motors and running gear are all rebuilt and reused. Diesel fuel savings of 40–60% and up to 80% pollution reductions are claimed over that of a "typical" older switching/yard engine. The same advantages that existing hybrid cars have for use with frequent starts and stops and idle periods apply to typical switching yard use. "Green Goat" locomotives have been purchased by Canadian Pacific Railway, BNSF Railway, Kansas City Southern Railway and Union Pacific Railroad

Cranes

Rail power Technologies Corp. engineers working with TSI Terminal Systems Inc. in Vancouver, British Columbia are testing a hybrid diesel electric power unit with battery storage for use in Rubber Tyred Gantry (RTG) cranes. RTG cranes are typically used for loading and unloading shipping containers onto trains or trucks in ports and container storage yards. The energy used to lift the containers can be partially regained when they are lowered. Diesel fuel and emission reductions of 50–70% are predicted by Rail power engineers.