Overview

GrünstromIndex offers an API suite designed to provide developers with access to real-time and forecasted data on the availability of green energy. The platform focuses on the current and predicted mix of renewable energy sources in the electricity grid, allowing applications to make informed decisions about energy consumption timing. This service is primarily aimed at developers building solutions for smart homes, electric vehicle charging infrastructure, energy management systems, and industrial automation where optimizing for lower carbon footprints is a priority.

The core utility of GrünstromIndex lies in its ability to offer granular data on the proportion of renewable energy in the grid at specific times and locations. This enables intelligent scheduling of energy-intensive tasks, such as charging electric vehicles or running household appliances, during periods of high green energy production. By shifting consumption to these times, users can indirectly contribute to reduced carbon emissions and potentially lower energy costs, depending on local energy tariffs. The API delivers data in a structured JSON format, which integrates with various programming environments, making it suitable for a range of applications from mobile apps to backend services.

GrünstromIndex provides three main data streams: the Live API for current energy mix data, the Forecast API for predictions up to several days in advance, and Historical Data for analysis and model training. The Forecast API is particularly relevant for planning scheduled events, allowing systems to anticipate future grid conditions and adjust consumption patterns proactively. This predictive capability supports advanced energy management strategies, moving beyond reactive responses to current grid status. Integration typically involves authenticating requests with an API key and parsing the returned JSON payloads. The platform's developer experience is supported by documentation and code examples for languages like Python and cURL, facilitating initial setup and integration with existing systems.

For scenario planning and strategic energy decisions, access to historical data offers a foundation for understanding past trends in green energy availability. This can be used to validate optimization algorithms or to identify recurring patterns that might influence long-term energy strategies. The concept of leveraging real-time energy data for demand-side management is gaining traction as a method to support grid stability and enhance the integration of renewable energy sources, as discussed by organizations focused on sustainable energy practices like the European Network of Transmission System Operators for Electricity (ENTSO-E).

Key features

  • Real-time Green Energy Data: Access current information on the proportion of renewable energy in the electricity grid.
  • Energy Forecasts: Obtain predictions for green energy availability and grid carbon intensity for up to several days in advance.
  • Historical Data Analysis: Retrieve past green energy data for trend analysis, model training, and performance validation.
  • Location-Specific Data: Query data relevant to specific geographical regions to ensure localized accuracy.
  • JSON API: Data is delivered through a RESTful API in a standardized JSON format, compatible with most programming languages.
  • API Key Authentication: Secure access to API endpoints using unique API keys for each application.
  • Developer Documentation: Comprehensive guides and code examples to assist with integration and usage.
  • GDPR Compliance: Adherence to General Data Protection Regulation standards for data handling and privacy.

Pricing

GrünstromIndex offers a free developer plan and various paid tiers. The pricing structure is based on the number of API requests and the forecast horizon provided.

GrünstromIndex API Pricing (as of 2026-05-28)
Plan Monthly Requests Forecast Horizon Price (per month)
Developer 5,000 1 day Free
Basic 100,000 3 days 25€
Pro 500,000 7 days 99€
Business Custom Custom Contact for Quote

For detailed pricing and plan specifics, refer to the official GrünstromIndex pricing page.

Common integrations

  • Smart Home Systems: Integrate with platforms like Home Assistant or custom IoT solutions to automate appliance usage based on green energy availability.
  • Electric Vehicle Charging Apps: Develop charging applications that optimize vehicle charging times to coincide with periods of high renewable energy.
  • Energy Management Platforms: Connect with building management systems or industrial control systems to schedule energy-intensive operations.
  • Data Analytics Dashboards: Incorporate green energy data into custom dashboards for monitoring environmental impact and energy efficiency.
  • Weather and Climate APIs: Combine with weather data, such as from OpenWeatherMap, to enhance predictive models for renewable energy generation, especially solar and wind.

Alternatives

  • Tomorrow.io: Offers weather and environmental data APIs, including some energy-related forecasts.
  • OpenWeatherMap: Provides weather data APIs, which can be a component in energy forecasting models.
  • electricityMap: Visualizes real-time carbon intensity of electricity consumption across different regions.

Getting started

To begin using the GrünstromIndex API, first obtain an API key by registering for a Developer Plan on their website. Once you have your API key, you can make requests to their endpoints. The following Python example demonstrates how to retrieve the current green energy index for a specific location using the requests library.

import requests
import os

# Replace with your actual API key from GrünstromIndex
# It is recommended to load this from an environment variable
API_KEY = os.getenv("GRUENSTROMINDEX_API_KEY", "YOUR_API_KEY_HERE")

# Define the API endpoint for live data
API_URL = "https://api.gruenstromindex.de/v1/live"

# Parameters for the request (e.g., a specific German postal code and radius)
# For a full list of parameters, consult the GrünstromIndex API reference:
# https://docs.gruenstromindex.de/api-reference/
params = {
    "postal_code": "10115", # Example: Berlin Mitte
    "radius": "10",       # Radius in km
    "api_key": API_KEY
}

try:
    response = requests.get(API_URL, params=params)
    response.raise_for_status() # Raise an HTTPError for bad responses (4xx or 5xx)

    data = response.json()

    print("GrünstromIndex Live Data:")
    print(f"Timestamp: {data['timestamp']}")
    print(f"Green Energy Index: {data['gsi']}")
    print(f"Carbon Intensity (gCO2/kWh): {data['co2_g_kwh']}")
    print(f"Renewable Energy Share: {data['renewable_share']:.2f}%")

except requests.exceptions.HTTPError as http_err:
    print(f"HTTP error occurred: {http_err}")
except requests.exceptions.ConnectionError as conn_err:
    print(f"Connection error occurred: {conn_err}")
except requests.exceptions.Timeout as timeout_err:
    print(f"Timeout error occurred: {timeout_err}")
except requests.exceptions.RequestException as req_err:
    print(f"An unexpected error occurred: {req_err}")
except KeyError as key_err:
    print(f"Missing key in API response: {key_err}")
except Exception as e:
    print(f"An error occurred: {e}")

This Python script sends a GET request to the GrünstromIndex Live API, providing a postal code and radius to specify the location. It then prints the timestamp, green energy index (GSI), carbon intensity, and renewable energy share from the JSON response. For detailed information on available endpoints, parameters, and response formats, refer to the GrünstromIndex API reference documentation.