Those of us who live in a city with a robust public transportation system know a good portion of that system involves buses. And for those in cities still running bus fleets on traditional fuel, we know what that exhaust does to our air and our lungs. With less than half of US buses running on alternative fuel or electric power, the country has a way to go to catch up to an electric bus overachiever like China, but with the worldwide goal of reducing global emissions, the US along with many other countries are stepping up to reduce emissions by increasing alternative fuel and electric bus usage.
Most city buses driving their route, running on fuel, emit nitrogen oxides (NOx), which are poisonous, highly reactive gases formed when fuel is burned at high temperatures. You may have even seen their brownish gas or smog (ozone), especially on a hot day, over your town. And we’ve all listened to the the impact of CO2 on our environment. Even though it is naturally occurring, we humans are adding far too much extra carbon into the atmosphere, furthering climate change. Knowing the average car emits around 6 tons of CO2 every year, reducing these emissions almost seems a moral imperative for us all.
Of course cities are switching to electric buses in an effort to reduce NOx and CO2, and will tout this as their main reason, but more likely they are looking at other benefits, like financial. The maintenance on an electric bus is practically negligible. Think no oil changes, fewer moving parts, reduced number of fluids, no spark plugs or wires, and longer lasting, regenerative brakes, and you can already see the savings in not only repairs but in uninterrupted service. Add a quieter engine to the mix and for honk-happy cities like New York, the noise reduction is a true blessing.
Charging an Electric Bus
Electric buses can save cities on fuel, oil, and maintenance, but how do they get their power and how often do they need it? Electric car chargers don’t charge fast enough to keep a city bus on schedule throughout the day, and most charges don’t last long enough to get the bus to the end of its route, but the combined charging system (CCS) is still common for overnight charging when time is not critical. But during the day, companies like ABB, Heliox, and Siemens have designed flash chargers that can charge a bus in 3-6 minutes. These new systems can even charge the bus faster than filling the tank at the gas pump. Properly spacing these efficient chargers along the bus route, passengers will never notice a lag in service.
These fast automated chargers use OppCharge, an open standard interface between electric buses and chargers offering charging power of 150kW. The benefits of OppCharge is that it can be used with any vehicle manufacturer or charging infrastructure, and they are backed by the cloud, which allows for remote diagnostics and over-the-air updates. They have also been designed to upgrade up to 450 kW should that become necessary. This gives cities not only the flexibility to buy from any bus manufacturer, but to easily upgrade when newer models are introduced with bigger batteries needing faster charging speeds.
The OppCharge system has automatic contact using a pantograph, wireless communication, contacting plates and infrastructure equipment that connects the bus to the pantograph. A pantograph is a hinged assembly that connects to the bus and provides conductive static charging. So the charger interfaces directly with the bus’ battery. Communication between the bus and charger is done via WiFi. The inverted pantograph allows for the use of an inexpensive, low weight interface on the roof of the bus. This new system gives cities opportunities to contribute positively to the environment without sacrificing any public service. Simply adding a network of fast charging stations to a bus route would allow for widespread adoption of electric buses.
Luxembourg Electric Buses
Already a pioneer in hybrid technology, Luxembourg was one of the first countries to implement hybrid buses in 2009. Volvo supplied Sales-Lentz, the leading bus operator in the Grand-Duchy of Luxembourg, with over 40 hybrid buses and will now equip them with full electric buses. Sales-Lentz now has an impressive fleet of 500 vehicles ready to meet all levels of public and personal transportation. And now with the May, 2017 introduction and installation of two OppCharge fast chargers along the route, the world is witnessing the viability of a citywide fleet of electric buses.
With their eye on the future, Luxembourg sees this new system as one step towards a sustainable, zero emission future. The Minister for Sustainable Development and Infrastructure in Luxembourg, François Bausch wisely sees the importance of their bus system as helping “to dramatically reduce the emissions of public transport and improve the environmental impact of public transportation.”
The Luxembourg charging station and bus stop were constructed by ABB and delivered to the Ministry of Sustainable Development and Infrastructure. ABB has about 5,000 fast chargers around the world. Beating Tesla to the punch, ABB even installed a fast charger for cars right in Tesla’s backyard in CA. And in October, 2016, ABB inaugurated the first bus charging station next to Volvo’s electric depot in Sweden.
The Volvo 7900 Electric Hybrid buses are designed for zero-emission areas and silent or safety zones and operate quietly and emission-free for about seven km. As compared to a diesel bus, the Volvo electric bus consumes 60% less energy with 75-90% fewer CO2 emissions and can run on electricity for 70% of its operating time. A small diesel engine extends their reach when needed, giving the buses even more flexibility.
UAF and Electric Vehicles
Where does a company like UAF fit into the electric bus and charging system? Because the buses run on battery power, there is a definite need to to keep the battery at an appropriate temperature. Not only do electric vehicles require battery cooling, but there can be no moisture or impurities, and the air used to cool the battery needs to be clean to prevent damage to the system components. Don’t forget, there is also a sophisticated computer operating these vehicles and internal temperature can adversely affect the entire system. UAF filters maintain thermal constancy and air purity.
We can’t forget that all vehicles have air conditioning, which requires filtering outside air to keep out particles as well as managing the recirculating air inside the cabin. A proper air filter can make the air in the car as clean as the air in a hospital operating room. UAF can design an air filter to any specification needed for any application.
The charging system is just as susceptible to heat and elements. Because the chargers are exposed to the environment and the connectors and parts are so sensitive and smart, maintaining flawless performance is paramount to all else. UAF helps keep the equipment within its optimal temperature range and keeps harmful particles from destroying the system’s functionality.