Load Management for EV Charging

Load management, also known as load balancing or load shifting, describes the active control of electricity consumption by means of targeted switching on/off or regulation of electricity-consuming devices. The aim is to not exceed a site’s given grid connection capacity and to optimally distribute the available electricity among all devices. Load management makes grid costs more transparent, and reduces them to their minimum. There are two distinct types of load management: static and dynamic. Due to its high electricity demand, EV charging infrastructure is the major use case for load management. Load management also enables individual prioritization, for example through tailored EV charging strategies.

Types of load management

Unmanaged

When no load management is applied to EV charging infrastructure (i.e. loads are not actively controlled), the assets are always provided with the requested load, in this case the amount of charge. Therefore, all EVs could charge with full power at all times. Without protection against overloads, the high loads of these simultaneous charging processes can easily cause fuses to blow and lead to blackouts. In addition, the sharp peaks drive up grid tariffs. If at all, this option is only recommended for the operation of a small number of charge points, as it is costly and risky.

Key aspects

• no management of loads
• charge points receive the requested load
• no overload protection
• high risk of blackouts
  

Use case

• not recommended, only suitable for site with very few charge points

Static load management

Static load management is a simple, but inflexible and inefficient form of load management. Here, the total available capacity of a grid connection point is permanently split into two parts: one for the existing building consumption (base load) – which is variable – and one for EV charging – which is capped at a static value. Usually, however, the required load of each charge point varies depending on its use. In this scenario, the base load can vary significantly, depending on the site’s consumption, while the maximum capacity of the charge points stays the same. On the one hand, this results in periods of unused capacity at the grid connection point (e.g. at night when the base load is low), which cannot be used for EV charging or other flexible consumption. On the other hand, static load management also does not protect against overloads in periods of high base loads.

Key aspects

• inflexible and inefficient management of loads
• fixed maximum capacity for EV charging
• fixed capacity per charge point
• when base load is low, free capacity is not used for EV charging
• risk of overloads in times of high base load

Use case

• sites with very stable base load

Dynamic load management 

Dynamic load management (DLM) is a highly flexible – and the most advanced – form of load management. It continuously adjusts the maximum EV charging capacity by adjusting the power supplied to the charge points according to the real-time load at the grid connection point. It therefore also takes the site’s base load into account, alongside all other loads, such as elevator, air conditioning, heat pump, photovoltaic system etc. If grid limits are about to be breached, the charge points are regulated to reduce consumption. In this way, dynamic load management enables permanent overload protection and ensures that the charging power is only limited in times of high base load.

As a result, DLM allows EVs to charge at their maximum, without causing unnecessary peaks. This enables more charge points to operate on existing grid infrastructure, while simultaneously reducing grid tariffs and alleviating concerns about overloads. By leveraging the flexibility of EV charging, DLM also enables more sophisticated prioritization logic to optimize a particular charging strategy according to an individual site’s needs. XENON makes a range of EV charging strategies possible to minimize costs and emissions and maximize user-friendliness.

Key aspects

• variable amount of electricity distributed to EV charge points according to the current base load at the grid connection point
• charge point control communicates with the energy meter
• if base load at a location is low, more capacity is made be available for charge points
• operating more charge points on existing infrastructure without expansion of grid infrastructure
• permanent overload protection as peak loads are avoided
• individual prioritization logic made possible

Use cases

• large residential complexes
• commercial properties, such as office buildings or hotels
• destination charging, such as retail, hospitality or fitness studios
• en-route charging on highways

By automatically adjusting the power supplied to charge points in response to a site’s base load, dynamic load management ensures maximum utilization of power at minimum costs. Unlike other forms of load management, it guarantees stress-free, user-friendly and reliable EV charging that never exceeds grid limits.