E-Mobility Fundamentals — Smart Charging
Knowing the EV charging industry’s complexity, I thought it would be a good idea to launch a series of blog posts on e-mobility fundamentals. The aim is to shed light on some of the topics that may not necessarily be clear to EV geeks!
You may also read the previous posts:
What is smart charging?
Smart charging is a convenient way of charging your electric vehicle (EV) at times when electricity demand is lower, for example at night, or when there is lots of renewable energy on the grid. Charging during these off-peak times not only reduces costs for EV drivers by using cheaper energy rates but also helps to prevent unwanted intervals of really high demand for electricity from the grid as illustrated in the following picture.
How does it work?
Smart charging can be done on the EV driver side or the e-Mobility Service provider (eSMP) and CPO side.
For an EV driver, a Time-of-Use tariff is applied, and the customer decides the timing to charge based on the price and needs.
However, in a supplier-managed charging, the charging and discharging decision is made based on multiple signals: real-time energy production, local energy consumption, as well as the state of charge information from nearby EVs and other electric devices.
We have 2 main forms of smart charging regarding the energy flow in the whole system:
- V1G — unidirectional, controlled charging, where charging infrastructure adjusts its rate of charging, based on grid requirements.
- V2G — vehicle-to-grid charging, where the vehicle’s battery is used to return energy to the grid during periods of high demand, and the vehicle is charged during off-peak times. The vehicle remains connected, and the smart charging management system adjusts the direction accordingly. Why do we need smart charging?
Benefits of Smart Charging
EV Smart charging provides significant benefits to the EV charging ecosystem as a whole. We can categorize the advantages based on the EV charging players:
- EV drivers: smart EV charging’s greatest incentive is cheaper, eco-friendly, and safer charging.
- CPO: charging point operators can benefit from smart charging by synchronizing their energy management systems with the distribution system operator (DSO) and any local distributed energy resource (DER) to get real-time energy production data and compare it with the local energy consumption. This way the CPO can avoid charging peaks and keep its competitive prices and increase customer satisfaction.
- Utility: smart energy management enables energy infrastructure (DSO, TSO, and generation plants) to optimize their infrastructure and operations by efficiently distributing the available power between vehicles and other power consumers.
How to implement smart charging?
I will highlight the available communication protocols (or application protocols) that define a system of rules. These protocols provide a detailed definition of the data exchange messages between EV charging parties. Any software that implements such a protocol, can be tagged as a smart charging software service. Let’s have a look at the smart charging protocols:
Open Smart Charging Protocol (OSCP)
OSCP is an open communication protocol between the charging point management system (managed by eMSPs and CPOs) and the energy management system of the site owner or the system of the DSO (Distribution System Operator). This protocol communicates a 24h forecast of the available capacity of the electricity grid. The Service Provider will fit the charging profiles of the electrical vehicles within the boundaries of the available capacity. OSCP, as well as OCPP, are hosted by the Open Charge Alliance.
OpenADR 2.0
OpenADR is an open, secure, and two-way information exchange model facilitating automated demand response (DR) actions that help balance grid supply and demand or mitigate high electricity costs. This protocol ensures that dynamic price and reliability signals are uniformly exchanged between utility companies, system operators, and energy management and control systems during DR events. Aggregated EV charging loads offer significant potential DR value and will likely become well-integrated with modern smart grids. The OpenADR Alliance fosters the development and adoption of the OpenADR standards.
Open Charge Point Interface protocol (OCPI v0.4)
OCPI is an open protocol between CPOs and eMSPs. This internationally supported independent interface supports affordability and availability of charging infrastructure. ElaadNL is one of the initiators. The protocol supplies correct charge station information such as location, availability and pricing, manages bilateral roaming, and allows for real-time billing and mobile access to charge stations. OCPI is facilitated by the Netherlands Knowledge Platform for Charging Infrastructure (NKL).
IEEE 2030.5 (IEEE Adoption of Smart Energy Profile 2.0 / SEP2)
IEEE 2030.5 is an IP-based application protocol for smart metering and automation of demand/response and load control in local or home area networks. It can be used in residential and commercial building settings to connect and manage devices using the Smart Grid.
ISO 15118
ISO 15118 Road vehicles — Vehicle to grid communication interface is an international standard defining a vehicle to grid (V2G) communication interface for bi-directional charging/discharging of EVs. The standard provides a Plug & Charge feature that enables an EV to automatically identify and authorize itself to a compatible charging station on behalf of the driver, to receive energy for recharging its battery.
I hope this brief introduction is enough to get to know smart charging and its protocols. In future posts, we will discuss more technical details about smart charging and e-roaming protocols. Stay tuned!
