Most people may associate Mercedes with high end sedans, but the company is a major player in the market for heavy duty vehicles like trucks and buses. Electric cars may be taking a longer time than expected to gain market acceptance, but Mercedes and other manufacturers are wasting no time getting electric bus and truck models to market.
The gloss on this story is that electric vehicles are far more environmentally friendly than their diesel powered cousins. Not only do diesel engines emit large quantities of carbon dioxide, they also spew millions of tons of nitrous oxides and sulfur dioxide into the atmosphere. Sulfur dioxide reacts with sunlight to create fine particulates — tiny specks so small they can be absorbed directly into the blood stream through the walls of the lungs. They are accused of being responsible for many health issues, especially respiratory, circulatory, and kidney disease.
While all of that is true, world manufacturers are not rushing their electric bus and truck offerings to market to make themselves feel good or save the earth. They are doing it because electric vehicles make economic sense for fleet operators. Electricity (in most places) costs less than diesel fuel. In addition, electric motors tend to last longer and require far less maintenance than diesel engines. After all, internal combustion engines have a thousand or more moving parts. Electric motors have as little as three.
“It’s all about cost, capacity, and range,” says Gustav Tuschen, the head of development at Daimler Buses in a press release. “Electric drive is no longer a niche, it’s a major player.” He promises the time for prototypes is over and it is now time for series production of the Mercedes Citaro E-CELL elecrtric bus to begin. Pre-production models are undergoing real world testing in extremely cold and extremely hot environments at present.
“By 2030, seventy percent of all newly-registered urban buses will have emission-free drive systems,” Tuschen says. Things may happen even sooner than that. The Chinese city of Shenzen — population 12 million — is on pace to have every bus in its enormous fleet powered by electricity before the end of 2017.
The Mercedes electric bus uses modular lithium ion battery packs so that it can tailor each one to the individual needs of its customers. Those who need shorter range can order buses with smaller batteries and pay less. Those who need longer range can order additional battery modules. Mercedes says its customers can order precisely the bus they need to meet their individual needs. Electric hub motors are used to propel the buses forward.
One factor that Mercedes’ engineers have worked hard at is maximizing the efficiency of the climate control systems used in its electric bus models. Heating and air conditioning can double the use of electrical energy or even triple it on cold winter days. In other words, on a cold, blustery, winter day as much as two thirds of the available battery power may be used to heat the interior.
“This means that we have to use intelligent energy management,” says Tuschen. In the new Citaro E-CELL line, heating and air conditioning control systems will react to traffic conditions and the number of passengers to optimize passenger flow so the bus spends less time at stops with the doors open.
Mercedes is active in another segment of the electric bus market as well. Just a few days ago, it announced that an electric school bus would soon be available to school districts in the US through its Thomas Built Buses division.
“The way of the future is to get new things done without abandoning what we already have,” says Mercedes. “Emission-free driving, partially autonomous vehicles, more attractive E-ticketing options, new layouts and faster passenger flows — the future of the urban bus is just arriving.” For the sake of the earth and the people who live on it, the future can’t get here fast enough.