node-red-contrib-effekttariff 0.2.2

Node-RED node for capacity tariff peak shaving — Swedish effekttariff and Belgian capaciteitstarief

npm install node-red-contrib-effekttariff

node-red-contrib-effekttariff

Node-RED node for capacity tariff peak shaving. Supports both Swedish "effekttariff" and the Flemish (Belgium) "capaciteitstarief".

Supported Regions

This node supports two capacity tariff models:

• Sweden (Effekttariff): Hourly measurement, 2-3 highest peaks per month, seasonal (Nov-Mar)
• Flanders, Belgium (Capaciteitstarief): 15-minute measurement, single highest peak per month, 12-month rolling average

Understanding Capacity Tariffs

Sweden (Effekttariff)

In Sweden, your total electricity cost is typically composed of two main parts:

1. Energy Cost (Spot Price): The price for the actual electricity (kWh) you consume. With a dynamic contract ("rörligt elpris med timprisavtal"), this price changes every hour based on the Nord Pool spot market.
2. Grid Fee (Nätavgift): What you pay to your local grid company (nätbolag) for grid maintenance and usage.

The Swedish power tariff (effektavgift) is based on the average of your 2-3 highest hourly consumption values during a month. These peaks are often only measured on different weekdays during specific "peak hours" (e.g., 07:00-21:00) and during winter months (November-March).

Flanders, Belgium (Capaciteitstarief)

Starting January 2023, households in Flanders (Belgium) have a capacity tariff based on:

• 15-minute measurement intervals (quarter-hourly peaks)
• Single highest peak per month determines monthly capacity
• 12-month rolling average for annual billing
• 24/7 measurement (no peak hours, no seasonal restrictions)
• Cost: ~€50/kW/year based on the rolling average

A single high-power event (like EV charging at 11kW) can significantly impact your annual capacity fee, making peak shaving especially valuable for households in Flanders.

How the Power Tariff Works

The goal of the power tariff is to encourage users to spread out their consumption and reduce load on the grid. It does this by adding a fee based on your highest consumption peaks.

Important: You must configure this node according to your specific grid company's rules, or use the region presets for quick setup.

Disclaimer: The peak reduction estimates provided by this node and its tools are theoretical. Actual savings depend on many factors including your consumption patterns, equipment response times, battery efficiency, and grid conditions. Results may vary from simulated values.

Installation

cd ~/.node-red
npm install node-red-contrib-effekttariff

Then restart Node-RED.

Usage

Example integration with Victron Energy: grid meter power feeds into the node; outputs drive the inverter current limit, Venus OS grid set-point, battery charge rate, and a Dashboard 2.0 chart.

Input

Connect a Grid Meter node (Power in Watts) to the input. The node expects positive values for grid import.

Outputs

1. Current Limit (A): Target current limit in Amperes. Connect to your ESS current limit control (e.g., Victron Ac/In/1/CurrentLimit). Only outputs when the value changes.

2. Status: Object with detailed peak data for debugging or dashboard display.

3. Charge Rate (W): Battery charge rate recommendation in Watts (only when battery charging is enabled). Connect to your battery charge controller to ensure the battery is charged before peak hours.

4. Chart Data: Array of chart-ready messages for Dashboard 1.0 and FlowFuse Dashboard 2.0. Connect to a ui-chart node to visualize consumption, limits, and peaks in real-time. Each message has a topic (series name) and a numeric payload (value in Watts or %). Series include: consumption, limit, target, peak_avg, battery_soc.

Configuration

Region Preset

Use the region preset dropdown for quick configuration:

Measurement Settings (Belgium/Advanced)

Peak Measurement (Sweden)

Limits

Electrical

Battery Charging (Optional)

Enable smart battery charging to ensure your battery is charged before peak hours. This allows effective peak shaving by having enough stored energy ready.

How it works:

• During off-peak hours, the node calculates how much time remains until peak hours
• It determines the energy needed to reach target SOC (minSoc + buffer)
• Outputs a charge rate that ensures the battery is ready before peaks
• During peak hours, charge rate is 0 (battery should be available for discharge)

Integration:

1. Set up a battery monitoring node to store SOC in global context
2. Configure the context keys to match your setup
3. Connect the third output (Charge Rate) to your battery charge controller

Status Indicator

• Grey ring: Off-season
• Green ring: Off-peak hours
• Blue ring: Learning phase (tracking but using minimum limit)
• Blue dot: Peak hours, usage well below target
• Yellow dot: Peak hours, approaching target (>85%)
• Red dot: Peak hours, over target (>105%)

Learning Phase

At the start of each month (or first use), the node enters a learning phase until it has recorded enough peaks. During learning, it outputs the minimum limit to prevent establishing unnecessarily high peaks.

Watts to Amps Conversion

• 1-phase: Amps = Watts / Voltage
• 3-phase: Amps = Watts / (3 × Voltage)

Example at 230V: 4 kW = 17.4A (1-phase) or 5.8A (3-phase)

Provider Examples

Sweden

Belgium (Flanders)

Quick Setup: Select "Belgium" from the Region dropdown to auto-configure all settings.

Future Development

This node is under active development. Future enhancements will focus on creating a more comprehensive "Cost-Saving Optimizer" by integrating dynamic spot prices.

• Flexible Tariff Models: Allow users to select their grid company's specific power tariff model (average of N peaks vs. single highest peak).
• Cost-Aware Logic: Make the battery charging and discharging logic aware of the hourly energy price. The system will then be able to make economic decisions, balancing the cost of the power tariff against the cost of the energy itself.

Battery Sizing Tool

An interactive web-based tool is available to help you understand how a battery can reduce your effekttariff peaks. The tool simulates different battery configurations and consumption profiles to estimate potential savings.

Try the Battery Sizing Tool (English/Swedish)

Features:

• Adjust battery capacity, charge rates, and SOC settings
• Choose from predefined consumption profiles (typical household, EV charging, heat pump)
• Configure your grid provider's peak hours and peak count
• Set your electrical installation (phases, breaker size)
• View simulated peak reduction with interactive charts

Note: The simulation results are theoretical estimates based on simplified consumption patterns. Actual savings depend on your real consumption behavior, battery efficiency, grid conditions, and other factors. Use the tool for guidance and planning purposes only.

Simulation & Testing

The package includes a simulation framework for testing and validating system behavior without connecting to real hardware.

Running Simulations

# List all available scenarios
npm run simulate

# Run a specific scenario
npm run simulate:scenario basicWeek

# Run all scenarios
npm run simulate:all

# Run with verbose output
npm run simulate:verbose basicWeek

# Generate HTML report with interactive charts
node scripts/run-simulation.js basicWeek --html

# Export data to CSV files
node scripts/run-simulation.js basicWeek --csv

# Generate both HTML and CSV
node scripts/run-simulation.js basicWeek --html --csv

Visualization Options

The simulation CLI supports two visualization modes:

HTML Report (--html): Generates an interactive HTML report with Chart.js charts showing:

• Hourly power consumption vs limit (line chart)
• Top recorded peaks (horizontal bar chart)
• Battery SOC over time (if applicable)
• Battery charge rate (if applicable)

The HTML file auto-opens in your default browser.

CSV Export (--csv): Exports simulation data to CSV files:

• *_hourly.csv - Hourly consumption data
• *_peaks.csv - Peak records with timestamps
• *_limits.csv - Limit changes over time
• *_battery.csv - Battery data (if applicable)

Output files are saved to ./simulation-output/.

Available Scenarios

Interactive HTML reports are automatically generated and available online. View all simulation reports

Running Tests

# Run all tests
npm test

# Run with coverage
npm run test:coverage

# Run in watch mode during development
npm run test:watch

License

MIT

Author

Dirk-Jan Faber