One of the main issues bus operators face as they transition to electric fleets is the ever-growing cost of charging their electric buses.
To understand why you need to consider smarter ways to charge your fleet take a look at the image below that compares the energy consumption rate across different vehicle types and even a skyscraper.
- the Chevy Volt charging rate is 3.3 kW,
- the medium-duty E-Truck charging rate is 15 kW
- the E-Bus charging rate is 60 kW.
As you can see, the total cost of charging a fleet of 50 electric buses can quickly surpass the total energy costs of a skyscraper. Thus, thinking of smarter ways to charge your fleet becomes imperative.
What is smart charging?
First, let’s take a moment to define smart charging. And probably the easiest way to understand Smart Charging is to compare it to regular charging.
When you plug a vehicle into a charger with regular (non-smart) charging, the vehicle will start charging immediately. In this case, the battery uses the maximum amount of power until charged completely. The only way to control the charging session is by unplugging or plugging in the vehicle.
Smart charging allows for much more control over the charging session. You can control remotely when, for how long, and how fast a vehicle charges. This process allows for maximum flexibility because it can be managed automatically. Additionally, it allows for a fleet approach, where some vehicles can charge faster or have priority over others, depending on your needs.
Smart Charging is sometimes referred to as intelligent charging, flexible charging, peak shaving or load balancing - though they are not really equivalent.
The Different Levels of Smart Charging
Although people talk about smart charging as one generic term, smart charging for electric buses come in different levels. There are no standard names for these levels, but based on our experience at ViriCiti, here are the names we assigned them, plus a definition of what each stands for.
Simple/Basic Load balancing
This is the most basic form of smart charging and it basically prevents overcapacity, by distributing the available capacity equally overall charging points at a given location. Basic load balancing is sufficient if you are looking to avoid grid limitation and peak time costs.
Scheduled/Static load balancing
This is one level up and on top of the equal distribution of load. It can optimize the charging schedule based on day/ night energy tariffs. With static load balancing you can plug your vehicles in as soon as they get to the depot, but they will start charging during low tariff hours.
Dynamic load balancing
This is the highest level of smart charging and can combine both static data and dynamic data, such as bus routes, next day planning, or dynamic energy pricing. With Dynamic load balancing, you can optimize the charging schedule, so your electric vehicles are charged on time for departure, with the right amount for completing their routes and at the lowest cost.
Making better decisions
I hope that this guide will provide you with a better understanding of what is possible and help you make more informed decisions.
And as you start looking for solutions that allow you to smart charge your fleet, remember to inquire what level each provider can offer and how deep can they integrate with your existent ITCS system.