Connection tariffs are the fees and pricing rules charged by a grid operator or utility for connecting a site to the electricity network and for maintaining that network capacity over time. In EV charging projects, connection tariffs can significantly influence total project cost, operating expenses, and decisions about charger power, load balancing, and phased expansion.
What Are Connection Tariffs?
Connection tariffs cover the cost of making an electrical connection available and, in many cases, the ongoing cost of reserving capacity on the grid. They can include:
– One-time connection charges (engineering review, new service line, metering setup)
– Network reinforcement charges (upgrades to cables, switchgear, transformers)
– Capacity-based charges tied to requested kW/kVA or fuse size
– Ongoing fixed charges for maintaining the connection
– In some markets, demand-related or peak-capacity charges that depend on maximum power draw
Why Connection Tariffs Matter for EV Charging
Connection tariffs often become one of the biggest cost drivers for public, commercial, and fleet charging sites. They matter because they:
– Impact CAPEX (upfront connection and reinforcement costs)
– Impact OPEX (ongoing capacity or network charges)
– Influence how many chargers can be installed without upgrades
– Drive the business case and charging ROI—especially for lower-utilization sites
– Encourage smart design choices like load balancing and phased deployment
Connection tariffs can make “more connectors at lower power” financially smarter than “fewer high-power chargers,” depending on the site use case.
Typical Components of Connection Tariffs
Connection tariffs often combine several pricing components:
Connection and Activation Fees
– Application and engineering assessment fees
– Physical connection work (service cable, switchgear interface)
– Metering installation and commissioning costs
Reinforcement or Upgrade Charges
– Costs to strengthen the local network if capacity is insufficient
– May include transformer upgrades, feeder upgrades, or MV/LV works
– Often site-specific and driven by the connection offer
Capacity Reservation Charges
– Fees based on contracted capacity (kW/kVA) or main fuse rating
– Charges for reserving network capacity even if not used continuously
– Can increase sharply when moving from LV to MV connection levels
Ongoing Network Charges
– Fixed monthly/annual charges for connection maintenance
– Sometimes includes service availability charges and administrative costs
Demand or Peak-Use Charges
In some tariff structures, costs depend on the highest measured demand:
– Maximum kW in a billing period
– Peak-time demand windows
– Penalties for exceeding contracted capacity
How Connection Tariffs Shape Charger Site Design
Connection tariffs directly influence engineering and commercial decisions, such as:
– Selecting AC charging (11–22 kW) for long dwell times to reduce connection capacity needs
– Using coincidence factor assumptions to model realistic peak demand
– Implementing load balancing to cap site import and avoid capacity upgrades
– Phasing the rollout: start with a smaller contracted capacity and expand later
– Adding on-site solar and energy storage to reduce peak import (where economically justified)
For fleets, optimizing charging schedules can reduce peak demand and lower tariff exposure.
Connection Tariffs vs Energy Tariffs
These are often confused but refer to different costs:
– Connection tariffs: cost of getting and keeping grid capacity available (infrastructure + capacity)
– Energy tariffs: cost per kWh consumed (the electricity price itself)
A site can have a low €/kWh energy tariff but still be expensive to operate if connection tariffs or peak charges are high.
Common Pitfalls
– Designing for maximum future power immediately, triggering unnecessary reinforcement costs
– Ignoring demand-based charges and then paying unexpected peak penalties
– Underestimating how tariff structure changes when moving from LV to MV connections
– Not aligning backend power caps with contracted capacity, causing exceedance events
– Overbuilding high-power capacity on sites with low utilization, damaging charging station profitability
Related Glossary Terms
Connection Offer
Connection Lead Time
Charging Capacity Planning
Load Balancing
Coincidence Factor
Peak Charging Power
Charging ROI
Grid Congestion
On-Site Energy Storage