Okt 15

Smart Charging Electric Buses: The Ultimate Guide

What is smart charging?

The easiest way to understand Smart Charging is to compare it to regular charging.

With regular (non-smart) charging as soon as you plug in a vehicle into a charger it will start charging. In this scenario, the battery demands the maximum amount of power until fully charged and the only way to control the charging session is by manually plugging in and plugging out the vehicle. 

Smart Charging, on the other hand, allows you to monitor and manage the charging session. This means you can control remotely when, for how long and how fast a vehicle charges. The process can be managed automatically giving maximum flexibility. Furthermore, it also allows for a fleet approach, where some vehicles can charge faster or have priority over others, depending on your needs. 

Smart Charging is also known as intelligent charging, flexible charging, peak shaving, or load balancing  – even though they are not always equivalent. 

Benefits of Smart Charging

The reason why operators are hesitant to expand their electric fleet is often due to the high costs related to energy, infrastructure, and network upgrades. 

The good news is that part of these costs can be avoided through Smart Charging.  Here’s what you can expect. 

Power peak reduction

When scheduling and managing your charging infrastructure, you are able to avoid charging your vehicles at peak times and exceeding your network operator’s maximum capacity, which will lower your energy costs. Charging speeds are optimally controlled so that buses are always charged, but refrain from exceeding the maximum grid capacity.

Lower Investment Costs

There is no need to upgrade your network to increase your power supply. This, along with the purchase of additional transformers can add up to a huge investment. With the right planning, you can make optimal use of your existing grid connection.

Smart charging allows you to control the charging speed of each individual charger. By prioritizing specific vehicles or balancing the available charging power, your charge capacity can remain the same, while your vehicles are still fully charged at the beginning of their service.

Energy cost reduction

Smart Charging allows you to take into consideration day and night tariffs and schedule charging sessions at the most cost-effective times. Your vehicles will still be charged on time, but your costs will drop. 

More flexibility

Through prioritized load balancing, buses are charged in relation to their schedules and the energy that their upcoming routes require. By connecting your vehicle- and charger data to your operational information, charging regimes become efficient and straightforward. Buses will automatically start -and stop- charging, ensuring that the buses set to leave the depot first are sufficiently charged at the time of departure.

Demand response

Respond instantly to dynamic energy pricing and accelerate or reduce the energy consumption of your fleet. With negative pricing becoming a reality, you might even be paid to charge your buses. 

Integration of batteries and renewable energy sources

Looking further into the future we anticipate that you will be able to significantly decrease your energy costs by integrating stationary batteries in your depot. You will be able to charge your stationary batteries at lowest costs when there’s an excess of energy from renewable sources, and later use it to charge your buses. 

On top of all this there are also a few less obvious benefits as the ones below. 

Reduce manual labor

Without smart charging, the only way to balance the load is to manually plug in and out the buses at specific times. This is time-consuming, error-prone, and costly as you need someone to stay in the depot overnight to follow this routine. 

While with smart charging, buses will automatically start -and stop- charging, ensuring that the buses set to leave the depot first are sufficiently charged at the time of departure.

Improved battery health

An inherent benefit but not always obvious is improving the state of health of your battery. Smart charging results in slower charging. And slow is healthier for batteries increasing battery life. Again this will save your operations costs in the long run.

So, what makes charging Smart?

In short, it’s data. The more information you can integrate the smarter the system gets. Through OCPP, charging profiles can be set enabling the control over the charging station and how much power is released at a time.  

In the context of electric buses, the relevant data comes from:

  • Infrastructure: grid limitation
  • Vehicles: battery capacity, SOC, max charging power of the battery
  • Chargers: max charging power of the charging station
  • Planning: when does a bus need to be on a particular block (service), and for how long
  • Route: how long is a particular block (service)
  • Energy grid: cost per Kwh at different times of the day, peak demand costs

Different levels of smart charging?

Even though most people talk about smart charging as one generic term, smart charging for electric buses comes in different levels. There are no standard names for these levels, so we took the liberty to name them and they are as follows: 

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 in your vehicles as soon as they get into the depot, but they will start charging during low tariff hours. 

Dynamic load balancing

This is the highest level of smart charging and it 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.

A practical example:

Let’s take a look at how smart charging can help a bus operator avoid peak demand charges. 

The above example shows a case in the United States where 60 buses were charged manually at the depot. It shows that buses are charged at night from around 8 PM till 3 AM most probably because that is when the buses are back at the depot, and this is the time period the buses require to fully charge. 

As can be seen on the graph, the peak load was reached around midnight at about 3000 kW. (Side note: In the US the energy tariffs are based on peak demand). The tariff in this scenario was around USD 20 per kW per month. This resulted in an approximate electricity bill of USD 60,000 per month!

The above example uses the same scenario WITH Smart Charging. By lowering the power, and spreading out the charging period over a longer period of time, a peak of 1850 kW was reached. In comparison to the non-smart charging example, this resulting in savings of USD 23,000. 

With planning data, scheduling and routes information taken into consideration. Not all buses needed to be fully charged at the same time. Priority could be given to some buses in the fleet. 

This example does not reflect all geographical locations. Needless to say, cost savings will differ per country depending on electricity networks and systems.

Smart Charging requirements 

To enable Smart Charging, your chargers need to be set up with the Open Charge Point Protocol (OCPP),  from version 1.6 onwards. This protocol allows a remote connection to your charging stations (fast chargers or slow chargers) directly via the internet. You won’t need anything else. 

“The Open Charge Point Protocol (OCPP) is an application protocol for communication between Electric vehicle (EV) charging stations and a central management system, also known as a charging station network, similar to cell phones and cell phone networks.  

The protocol is an initiative of the ELaadNL foundation in the Netherlands. Its aim was to create an open application protocol that allows EV charging stations and central management systems from different vendors to communicate with each other. It is in use by a large number of vendors of EV charging stations and central management systems all over the world”.  – from Wikipedia 

Important to know: Smart Charging is not restricted to specific OEMs. 

One exception is the BYD buses and chargers, that use a proprietary operating system to communicate. 

Best Smart Charging solution for electric bus and truck fleets

Have you experienced challenges with your charging infrastructure as your electric fleet is expanding? 

ViriCiti offers the best Smart Charging solution for electric bus and truck fleets. The Smart Charging package is optimized for medium and heavy-duty vehicles such as electric buses, electric trucks, as well as light electric vehicles. 

ViriCiti has the number one all-in-one platform in the Americas and Europe with more than 7 years experience in electric bus fleet management. 

ViriCiri already integrates with a number of charging station manufacturers including ABB, Heliox, Furrer + Frey, Ebusco, Opbrid, and Schaltbau. 

For more information click here to request a demo.

About The Author

We are the ViriCiti marketing team. A group of EV enthusiasts writing about the most important aspects of operating electric fleets. From monitoring to smart charging.