What do you get when you combine some of the most advanced pieces of green technology in the marketplace today? It might look something like the new EcoSaver IV hybrid buses from DesignLine.
First, the basics. The buses in question are built by North Carolina-based DesignLine International and feature wide entry doors, super-low floors, and room for 42 passengers. Earlier versions of the EcoSaver hybrid system have been powering these buses for the past ten years. As far as mass transit goes, not a bad start. However, it gets even better when you peek under the hood of the latest generation.
The idea of microturbines in a vehicle is nothing new. The Chrysler turbine car is a throwback all the way to the 1960s. However, while extremely efficient at maximum RPMs, their efficiency falls off precipitously in non-optimal driving conditions. These factors doomed early turbine car programs.
Today, however, series hybrid drive trains give a whole new twist on the concept. Rather than having the turbine connected to a transmission to turn the wheels, it runs a generator. In this environment, it can take all the time it needs to start up, run in its ideal operating conditions, then shut off. You get all of the benefits (smooth operation, flex fuel, efficiency, etc) with none of the penalties.
In this vein, DesignLine purchased an initial order of 30 C30 Capstone Microturbines. These microturbines have only one moving part that floats on an air bearing (near-zero friction, no wear), are rated for 16 million+ hours, and a single turbine can burn your choice of diesel, biodiesel, jet fuel, or kerosene. A different version that burns natural gas is also available.
But the story gets more interesting from there, for better than a normal hybrid is a plug-in hybrid, and that’s just what the EcoSaver IV hybrid system is. They’re not just using any batteries; they’ve placed an order for the cells for their first four, 44kWh “Nano-titanate” battery packs from AltairNano and are preparing to build more. AltairNano’s advanced lithium-ion cells, while having only marginally higher energy density than nickel metal hydride, have incredible power density, can charge in under ten minutes, and can withstand tens of thousands of charge cycles under almost any conditions.
All together, DesignLine’s latest generation of buses spend a third of their time running only on electricity, and when they’re not, they can operate on a wide range of fuels, netting twice the efficiency of normal busses and saving 6,000 gallons of diesel per year.
Image Credit: Adam E. Moreira (GFDL)