(DGIwire) – An all-electric bus fleet is great for the environment—especially at a time when the world’s population centers are growing into megacities clogged with traffic. But the idea presents a challenge. How can sufficient energy be supplied to recharge hundreds of buses simultaneously at night? With an electric fleet, energy needs to be available to be able to plug multiple vehicles in at the same time. As a recent article in Motorindia notes, this presents a challenge in areas where the electric grid may not be particularly reliable.
“A potential solution involves a phenomenon known as ultra-fast charging, in which the prohibitively long charging times encountered with existing batteries for electric vehicles are drastically reduced,” says Stephen Voller, author of the Motorindia article and CEO of ZapGo Ltd. “One technology that can make this potentially viable is Carbon-Ion (C-Ion®) cells, a fast-charging and safe alternative to lithium-ion batteries, the standard energy source for electric vehicles today.”
As Voller writes, C-Ion cells allow energy to be safely transferred to electric vehicles using extremely fast charging rates. Banks of C-Ion cells can be used to buffer the grid, and very-high-rate direct current chargers could then be connected to the C-Ion banks operating at 350kW, 450kW or even as high as 1,000kW. These DC chargers could be installed at bus depots without the need to install new grid infrastructure. ZapGo Ltd is already working with utility companies on a grid storage product that would utilize large banks of its C-Ion batteries to provide high rates of charging at locations such as truck stops; bus depots easily could be another type of location where they are set up.
Municipalities can make money from the Microgrid as a Service (MaaS) or Electrons as a Service (EaaS) model. This involves buying and storing energy at off-peak times, or at night, and selling the electricity during the day at peak times. Clearly this has major benefits when used in conjunction with variable renewal generation systems like wind or solar.
There are several potential benefits to the scenario in which large C-Ion batteries or storage containers are situated at bus depots. As in the MaaS model, these could be filled up at night or during periods where the grid is running reliably; when a bus pulls up, it is then charged from the stored energy on site rather than from the grid directly. This provides a significant cost savings because off-peak electricity rates are comparatively lower than peak rates. It also avoids a nightmare scenario in which a multitude of buses require recharging in the middle of a night on which the electric supply is not available.
Separately, as an electric bus is proceeding on its regular route during the day, there will be multiple idling points, such as when the driver is taking a break. Recharging stations can be set up at these break points to minimize inconvenience to the driver and passengers alike.
“The move toward all-electric bus fleets is not only a good idea; the goal can potentially be achieved with a significant amount of cost savings and efficiency through the use of ultra-fast charging—made possible with burgeoning technologies such as C-Ion,” Voller adds.