Opportunity Billing vs Deposit Billing
The charging of electric buses has so far been done overnight in depots. However, if the daily operating range of the bus exceeds the actual range the driver is able to achieve, local transport authorities are often left with two options. These two options are buying an electric bus with a bigger battery, which costs more or buying a secondary bus to replace its service while the first one is charging. Both options are more expensive than traditional diesel buses. Not to mention that charging an electric bus during the day at the depot can incur costly peak charges. The term “opportunity charging” refers to charging an electric vehicle for short periods throughout the day instead of fully charging it all at once. In short, you charge the battery whenever the opportunity arises.
Wireless inductive charging best offers its benefits when applied as an on-road charging system. Wireless charging equipment installed at one or both ends of a route typically charges the batteries for 5-10 minutes while the bus waits at the terminus before the start of a new/round trip. With an automated charging process like wireless charging, one can integrate the charging process into the usual mode of operation by installing chargers where the bus should stop anyway or by charging while driving (so-called wireless charging). dynamic thread). Wireless chargers can also be strategically installed at bus stops for grazing charging while letting passengers hop on and off. The charging process integrates seamlessly into day-to-day operations, enabling continuous service, optimal fleet uptime and high efficiency. IDTechEx’s latest report, “Wireless Charging Market for Electric Vehicles 2023-2033: Technology, Players and Forecasts”, covers the necessary enablers on both ground-side and vehicle-side.
Benefits for battery life
Lithium-ion batteries degrade with use. Overnight or deep cycle discharge damages batteries and high charge rates degrade batteries due to the temperature created. Studies have also shown that recharging batteries during the day avoids having to charge batteries from deeply depleted states, thereby extending battery life. Shallow, frequent battery charging is known to be better for battery life than deep, infrequent charging. Wireless charging with multiple ground pads installed allows the battery to be charged in a shallow and frequent charging pattern, maintaining it at an optimal state of charge between 45-75% during operation. However, more pedestals on the ground will require a larger initial investment. Research from IDTechEx reveals that 70% of infrastructure value is in ground assembly (GA) and high power wireless charging systems can cost up to $50,000 for GA alone.
Battery size reduction potential
Although high-powered wireless chargers can be expensive to install, they pay back their investment in different ways. An added benefit of opportunity pricing is that when buses return with a higher state of charge, costly peak demand loads at the depot are reduced. Second, wireless opportunity charging can significantly reduce the battery capacity required. Instead of running around with tons of batteries, buses focus on transporting people. Wireless Opportunity Charging technology increases the profitability of an electric bus fleet as more frequent but shorter charging cycles reduce required battery capacity and improve battery life. As a result, operators of electric bus fleets can buy cheaper buses with smaller batteries. The IDTechEx report includes operational analysis of real-world case studies highlighting the cost savings achieved by some transit authorities. Considering the example of an all-electric BYD K9 bus (the K9 is its best-selling model), research by IDTechEx revealed that the ability to reduce the battery from 138 kWh (to about half the original weight ) can result in savings of approximately $55,000. by bus.
Potential for battery size reduction enabled by Wireless Opportunity Charging. Source: IDTechEx
Players and Deployment
Companies like WAVE, InductEV (formerly Momentum Dynamics) and IPT are involved in wireless bus charging. The IDTechEx report includes their comprehensive company profiles, benchmarking of their technology based on power, efficiency, air gap and vehicle cushion weight levels, as well as detailed deployment data . Additionally, companies like Electreon are included in the report – companies working with major OEMs to bring dynamic wireless charging to market. However, they are expensive to deploy – research by IDTechEx estimates that an electric road system would cost around $1.5 million per kilometer. Overall, wireless spot charging is a promising new technology that offers major benefits to transit authorities. The IDTechEx report, “Wireless Charging for Electric Vehicles Market 2023-2033: Technology, Players and Forecast”, provides a comprehensive analysis of this emerging charging technology that is expected to support the adoption of electric buses globally.
