The fair-share principle is a key distribution mechanism in the dynamic charging management of charging parks, fleet locations, and public charging infrastructure. When grid connection capacity is limited, it ensures that multiple electric vehicles can be charged simultaneously and according to demand.
Definition of terms
The fair-share principle is a method for distributing limited charging power within the charging infrastructure. Under this principle, the power available at the grid connection point is distributed among all active charging points in such a way that the available capacity is utilized as fully as possible and no single vehicle is unnecessarily disadvantaged. Unused power is automatically made available to other vehicles. It is an important component of modern load management and charging management systems for charging stations and charging infrastructure.
The term “grid connection capacity” is used here to refer to the equitable distribution of available power among all charging points—a usage that is not standardized across the industry in this form but has become established in practice as a clear description.
How It Works
The fair-share principle consists of four steps:
- The total available power at the grid connection point is determined
- The total available power is divided by the number of active charging points or vehicles—this ratio is the fair share
- If a charging point does not use its full allocation, the remaining power is distributed proportionally among the other active charging points
- Whenever vehicles are added or removed, the distribution is recalculated
Real-World Example at the Charging Station
A charging station has a grid connection capacity of 300 kW and eight charging points. When multiple electric vehicles are charging at the same time, the fair-share principle distributes the available power to the individual charging points based on demand. This allows the existing infrastructure to be used efficiently without having to expand the grid connection.
Distinction from Other Distribution Logics
The fair-share principle is one of several possible allocation strategies within dynamic charging management—and should not be equated with the other approaches:
- Static charging management (equal distribution): Each active charging point receives the same amount of power, regardless of actual demand—the opposite of fair-share
- Fair-Share Principle: Available power is distributed according to need, so that each vehicle receives as closely as possible the power it requires, and unused power automatically benefits others
- Priority-based charging: certain user groups or vehicles are given priority — this is also not a fair-share approach, but rather an alternative approach
Okean always distributes power according to the fair-share principle and does not give preference to any individual charging points.
Benefits for Charging Infrastructure Operators
- Optimal use of the available grid connection capacity
- uniform availability of charging stations
- Higher customer satisfaction through reliable, needs-based charging capacity
- A basis for expanding additional charging stations without immediately expanding the grid
- resulting in higher sales of electricity
Limitations of the Fair-Share Principle
The benefits of the fair-share principle diminish as grid connectivity becomes increasingly scarce, since the available charging power must be distributed among an ever-growing number of vehicles, and the power available per vehicle decreases accordingly. In such cases, supplementary measures such as battery storage, pre-charging storage, or peak shaving are advisable.
Relation to dynamic charge management
Dynamic charging management monitors the available power at the grid connection and distributes it according to a defined distribution logic. The fair-share principle describes one possible logic for this power distribution—alongside other approaches such as first-come, first-served or priority charging.
Frequently Asked Questions (FAQ)
What is the fair-share principle?
The fair-share principle distributes the power available at the grid connection point to all active charging points based on demand, so that as many vehicles as possible can be charged at the same time.
Is Fair Share the same as dynamic load management?
No. Dynamic charging management is the overarching control concept; the fair-share principle is one of several possible allocation strategies within this concept.
Does the “fair share” principle favor certain vehicles?
No, unlike priority-based methods, in a true fair-share system, all active charging points are treated equally.
Distinction from related terms
Not to be confused with:
- Dynamisches Lademanagement: übergeordnetes Steuerungskonzept zur Regelung der verfügbaren Ladeleistung. Das Fair-Share-Prinzip kann dabei als eine mögliche Verteilungslogik eingesetzt werden
- Demand Side Management (DSM): übergeordnetes Konzept zur Steuerung und Optimierung von Energieverbräuchen. Es wird in vielen Bereichen eingesetzt und ist nicht auf Ladeinfrastruktur beschränkt
- Peak Shaving für Ladeparks: Verfahren zur Reduzierung von Lastspitzen am Netzanschlusspunkt. Im Fokus steht die Begrenzung der Gesamtleistung, nicht die Verteilung der verfügbaren Leistung auf einzelne Ladepunkte
Summary
The fair-share principle ensures that as many vehicles as possible can be charged simultaneously at charging stations, based on demand. It is one of several allocation strategies within dynamic charging management—unlike rigid equal distribution or priority-based charging, it ensures fair, demand-based use of the available grid connection capacity.
Note: This article is intended for general informational purposes only and is not a substitute for individual legal, technical, or financial advice.
