In recent years, more cities have switched to electric buses. This trend is hitting not only capital cities but provincial towns as well. At present, the highest concentration of electric buses – 99% of the total – is in China. The city of Shenzhen has already replaced its entire diesel fleet.
This healthy trend is catching on in other countries too: It has taken Moscow just two years to launch 500 rapid-charge electric buses.
The number of electric buses is also increasing in other European cities such as London, Paris and Berlin. The city of Grodno in Belarus uses in- motion charging buses, making it possible to link routes at different ends of the city. It seems we are finally witnessing the start of mass decarbonization of surface transport.
A logical question arises: why has mass production of electric buses become possible only now?
The heart of any electric vehicle is its battery. The batteries used in electric buses are variants of the lithium-ion battery, which first appeared around 30 years ago. Initially, this type of battery became widely used in IT gadgets, specifically laptops and phones. With the development of the gadget market, lithium-ion batteries were improved and put into production on an industrial scale. The batteries’ chemical compounds became safer and manufacturing costs fell. These factors enabled the use of lithium-ion batteries in electric vehicles, including electric buses, and jumpstarted the “electric race” and rapid development of the industry.
At first glance, it may seem simple to replace diesel buses with electric ones. But in fact, the batteries in these electric buses must meet a number of criteria: they must be safe, environmentally clean, light, efficient and economical. The ideal solution is the lithium-titanate battery.
There are currently three types of electric bus: the depot charging bus, the opportunity charging bus, and the in-motion charging bus. Lithium-titanate batteries are suitable for the second and third types and are considered the best for good reasons. First, they are safe in every respect -- both for the environment and from the technical standpoint. Second, they are perfect for cities with wide temperature ranges and work even in strong frosts. (Think Moscow.) Third, they are economically efficient.
Admittedly, the cost of manufacturing lithium-titanate batteries is more expensive than others, but they have a service life of around 15 years, which is three times longer than batteries of other types. As a result, based on its full lifecycle, the lithium- titanate battery is the cheapest and most economical. And as the scale of production has expanded, the average cost of this type of battery has nearly halved over the past 10 years.
Another attractive feature of lithium-titanate batteries for electric buses is the ability to use rapid-charge technology. The buses can recharge at their route terminus in just a few minutes and travel 300-400 kilometers per day, thereby satisfying another important requirement of public transport in contemporary cities – continuous service.
Many people may argue that electric buses charged at night are more suitable for such purposes. Indeed, it would be possible to charge such buses overnight so they can operate all day. But the size and weight of the battery would have to be substantial: 3 to 4 tons, compared to just 1.5 tons for a rapid-charge bus. And given an average passenger weight of 75 kilograms, that would reduce the potential number of passengers by 20 to 35.
In a megacity where the passenger capacity of public transport is vital, the lithium-titanate battery wins every time. Furthermore, over the 15-year lifecycle of a rapid- charge bus the volume of recycled batteries would be 12 times less than when using electric buses with night charging.
For now, the lithium-titanate battery is the best type of battery for electric buses. The closest alternatives are inferior in efficiency and quality, and no new developments appear to be on the way over the next few years.
Thanks to technological progress and mass production, electric buses are becoming a symbol of change: it is with public transport that the trend towards environmentally clean transport is beginning. In some cities, the surface transport fleet could be switched to electricity within 5-10 years. The break-even point for electric buses has been found, and the lithium-titanate battery has played an important role in this. The green revolution can no longer be stopped and the first “bus wave” is already here.
Sergey Ivanov is CEO of private engineering company Drive Electro, a Russian leader in production of electric and hybrid systems for commercial vehicles and public transport. Drive Electro, founded in 2007 and based in Moscow, created several firsts in Russia--the e-bus, trolleybus and e-truck.