Smart Charging Glossary

Energy & Power Units

kWh — Kilowatt hour

A unit of energy. One kWh is the amount of energy consumed by a 1 kW device running for one hour. Used to measure how much energy a battery stores or an EV consumes.

kW — Kilowatt

A unit of power, measuring the rate of energy transfer. A 22 kW charger delivers energy faster than an 11 kW charger. Your contracted transport capacity (GTV) is also expressed in kW.

kVA — Kilovolt-ampere

A unit of apparent power, combining both active (useful) and reactive power. Grid connections and transformer capacity are often rated in kVA.

kVAr — Kilovolt-ampere reactive

A unit of reactive power. Reactive power does not perform useful work but is necessary to maintain voltage levels in the grid. DSOs may charge for excessive reactive power.

Smart Charging & Grid

GTV — Gecontracteerd Transportvermogen (Contracted Transport Capacity)

The maximum power (in kW) that your grid connection is contracted for. Exceeding this limit results in penalty charges from the DSO. Stekker’s kW-max protection prevents this.

DSO — Distribution System Operator

The company that operates the local electricity distribution grid (e.g., Liander, Stedin, Enexis in the Netherlands). DSOs are responsible for maintaining grid capacity and may impose congestion signals.

TSO — Transmission System Operator

The operator of the high-voltage electricity transmission grid at national level (e.g., TenneT in the Netherlands). TSOs manage grid stability and ancillary services markets.

Grid congestion

A situation where electricity demand exceeds available grid capacity at a specific location or region. Smart charging can respond to congestion signals from DSOs to reduce load during peak periods.

Peak shaving

Reducing maximum power draw by spreading consumption more evenly over time. This avoids exceeding your contracted transport capacity and prevents costly demand charges on your energy bill.

Load balancing

Distributing available power across multiple charge points and other assets to prevent exceeding grid connection capacity. Ensures all vehicles charge while staying within safe limits.

Grid-aware charging

Charging that adapts to real-time grid conditions — including congestion signals, energy prices, and available capacity. Goes beyond simple timer-based charging to actively protect the grid.

Self-consumption

Using locally generated solar energy directly on-site rather than exporting it to the grid. Smart charging can shift EV charging to sunny hours to maximize self-consumption and reduce energy costs.

Fuse limit

The physical amperage limit of the main fuse at your grid connection. A hard constraint that cannot be exceeded without risking power outage. Stekker always respects fuse limits as a safety boundary.

Grid connection (netaansluiting)

The physical and contractual connection point between your building and the electricity grid. Defined by its fuse limit and contracted transport capacity (GTV).

Demand response

Adjusting energy consumption in response to grid signals or price signals to support grid stability. Smart charging is one of the most flexible forms of demand response.

Curtailment

Deliberately reducing power output of a device (e.g., solar panels or chargers) to stay within grid constraints. A last resort when other optimization strategies are not sufficient.

EV Charging

V1G — Vehicle-to-Grid (unidirectional)

Smart charging where the charging speed is varied based on grid conditions, energy prices, or solar production. Energy flows one way: from grid to vehicle. This is what most smart charging systems use today.

V2G — Vehicle-to-Grid (bidirectional)

Bidirectional charging where EVs can both charge from and discharge back to the grid. This turns EV batteries into distributed energy storage, enabling services like peak shaving and grid balancing.

V2H — Vehicle-to-Home

Bidirectional charging where the car returns power to the house instead of the grid. Acts as a home battery, useful during power outages or to maximize solar self-consumption.

SoC — State of Charge

The current charge level of a battery, expressed as a percentage (0-100%). Stekker uses SoC information to plan optimal charging schedules and ensure vehicles reach their target charge level.

EVSE — Electric Vehicle Supply Equipment

The physical charging equipment — the charger itself, including its connectors. Each EVSE can have one or more connectors (e.g., Type 2, CCS).

Charging profile

A time series of power setpoints sent to a charger via OCPP. Tells the charger exactly how much power to deliver at each moment. Stekker generates optimized charging profiles automatically.

Charging session

The period from when a vehicle plugs in until it disconnects. Stekker optimizes each session based on departure time, energy needs, grid conditions, and pricing.

Charge card (laadpas)

An RFID card used to authenticate and start charging sessions. In Stekker, charge cards can be assigned individual charging preferences and priority levels.

CDR — Charge Detail Record

A standardized record of a completed charging session containing energy delivered, duration, costs, and identification data. Used for billing and reporting.

Industry Roles

CPO — Charge Point Operator

A company that manages charging infrastructure: installing, maintaining, and operating charge points. CPOs handle billing, authentication, and communicate with platforms like Stekker via OCPP or OCPI.

CPMS / CSMS — Charge Point Management System

Backend software used by CPOs to manage their network of charge points. Stekker integrates with CPMS platforms to add smart charging capabilities without replacing existing systems.

eMSP — e-Mobility Service Provider

A party providing EV charging services to drivers — handling roaming, payments, and charge cards. eMSPs interact with CPOs via the OCPI protocol.

SCSP — Smart Charging Service Provider

Stekker’s role in the ecosystem: providing smart charging optimization as a service to CPOs, installers, and fleet operators without replacing their existing infrastructure.

EMS — Energy Management System

A system that coordinates charging, generation, storage and consumption at a location to optimize for cost, grid constraints and priorities. The Stekker Engine is an EMS specifically designed for smart charging.

CEM — Customer Energy Manager

In the S2 standard: the controller that coordinates multiple flexible devices (chargers, batteries, heat pumps) at a customer location. Stekker acts as the CEM.

Aggregator

An entity that bundles demand response from multiple sites to participate in energy markets or provide grid services. Smart charging can contribute to aggregated flexibility portfolios.

Protocols & Standards

OCPP — Open Charge Point Protocol

The standard protocol for communication between charge points and backend systems. Stekker supports OCPP 1.6 and 2.0.1, sending optimized charging profiles to chargers in real time.

OCPI — Open Charge Point Interface

A protocol for data exchange between CPOs and eMSPs, enabling roaming and interoperability. Stekker uses OCPI to integrate with partners like E-Flux and Evesto.

S2 (EN 50491-12-2)

An open European standard for communication between energy management systems and flexible devices. Enables vendor-neutral control of chargers, batteries, and other flexible assets via WebSocket connections.

OpenADR — Open Automated Demand Response

A standard for automated demand response, enabling charge points and batteries to follow grid signals from DSOs and TSOs. Stekker supports OpenADR for congestion management.

MQTT

A lightweight messaging protocol used for real-time communication between Stekker Edge devices on-site and the Stekker cloud platform. Provides reliable, low-latency data exchange.

Modbus

An industrial communication protocol used by Stekker Edge to read real-time data from energy meters and inverters at the customer site. Enables faster local response times than cloud-only setups.

Energy Markets

Day-ahead market

The electricity market where hourly prices for the next day are determined through an auction. Stekker uses day-ahead prices to schedule charging during the cheapest hours.

Dynamic pricing / Dynamic energy contract

Electricity pricing with rates that vary by the hour based on wholesale market prices. Smart charging maximizes savings by automatically shifting consumption to low-price periods.

EPEX Spot

The European Power Exchange where day-ahead and intraday electricity is traded. Dutch and Belgian electricity prices are determined here. Stekker fetches these prices for optimization.

Imbalance price (onbalansprijs)

The real-time settlement price from the TSO for deviations between planned and actual electricity consumption. These prices can be very volatile and represent additional optimization opportunities.

PTU — Programme Time Unit

A 15-minute interval used in Dutch electricity market settlement and grid measurement. All energy flows are measured and settled per PTU. This is why kW-max is based on 15-minute averages.

GOPACS

A Dutch platform for market-based congestion management. Allows grid operators to request load shifts from market participants. Stekker can respond to GOPACS signals by adjusting charging schedules.

HBE credits — Hernieuwbare Brandstof Eenheden

Dutch renewable energy certificates earned through compliant reporting that proves simultaneous renewable generation and EV charging. Represents additional revenue from green charging.

Control & Optimization

BESS — Battery Energy Storage System

A stationary battery installation used to store and release electricity. When combined with smart charging, a BESS can absorb solar peaks, reduce grid demand during high-load periods, and provide backup power.

Model Predictive Control (MPC)

A control strategy that uses a mathematical model of the system to predict future behavior and optimize decisions at each time step. Stekker’s engine uses MPC to plan charging schedules that minimize costs while respecting grid limits and charging deadlines.

Digital Twin

A digital representation of a physical system — such as a charging site with its chargers, solar panels, and grid connection — that can be used to simulate and optimize behavior before applying changes in the real world.

Flexible assets

Devices that can adjust their energy consumption timing without impacting their core function. EVs, batteries, and heat pumps are flexible assets — their energy use can be shifted to moments that are better for the grid and cheaper for the customer.

Five levels of smart charging

Stekker’s framework for categorizing charging intelligence: Level 1 (manual timer), Level 2 (scheduled charging), Level 3 (price-optimized), Level 4 (grid-integrated), Level 5 (autonomous, self-regulating). Most Stekker customers operate at Level 3-4.

Stekker Platform

Stekker Engine

The AI-powered optimization core of the Stekker platform. Generates optimal charging profiles by considering 20+ metrics including energy prices, solar forecasts, grid constraints, and vehicle priorities.

Stekker Edge

An on-site hardware module (based on the Teltonika RUT956 router) installed in the customer’s meter cabinet. Reads real-time data from energy meters via Modbus and executes charging plans locally for faster response times.

Pairing code

A short code entered in your CPO’s management system to link a charge point to your Stekker account. This is how Stekker connects to your existing charging infrastructure without replacing it.