Innovating Energy Billing Systems: How Developers Can Use Energy API for Enhanced Customer Transparency

Introduction

In the rapidly evolving energy sector, transparency and accessibility of market data are paramount for developers, energy traders, and sustainability teams. Traditional methods of obtaining energy market data often involve scraping government portals or stitching together disparate data sources, which can be time-consuming and error-prone. This is where Energy API comes into play, offering a unified REST API that aggregates wholesale energy market data from trusted sources like OMIE, ENTSO-E, and EIA. By leveraging this API, developers can enhance customer transparency and streamline their data integration processes.

This blog post will explore how developers can utilize the Energy API to innovate energy billing systems, providing enhanced transparency for customers. We will delve into the API's features, core endpoints, and real-world use cases, demonstrating how it can solve common challenges faced by energy professionals.

Why Energy API

The Energy API stands out in the crowded landscape of energy data solutions for several reasons:

• Unified Data Format: The Energy API normalizes data from various sources into a single JSON interface. This eliminates the need for developers to handle multiple formats, schedules, and naming conventions, significantly reducing the time spent on data integration.
• Comprehensive Coverage: With over 39 symbols across six commodity categories—electricity, natural gas, crude oil, coal, carbon allowances, and grid carbon intensity—the API provides a holistic view of the energy market. Developers can access multiple commodities in a single API call, streamlining their data retrieval processes.
• Robust Endpoints: The API offers 16 endpoints covering a wide range of functionalities, including spot prices, historical data, intraday curves, and cost estimates. This versatility allows developers to build sophisticated applications without extensive ETL work.
• Trusted Data Providers: The Energy API aggregates data from reputable sources, ensuring that developers have access to reliable and accurate market information. This trustworthiness is crucial for applications that rely on real-time data for decision-making.

Quick Start

To get started with the Energy API, you will need to familiarize yourself with the base URL and the authentication method. The base URL for the API is:

https://energy-api.com/api/v1

Authentication is done via the api_key query parameter. Here’s how you can make your first request to retrieve the latest prices for a selection of commodities:

curl -G https://energy-api.com/api/v1/latest \
--data-urlencode "symbols=BRENT_CRUDE,TTF_GAS,EUA_CO2" \
--data-urlencode "api_key=YOUR_API_KEY"

The expected JSON response will look like this:

{
"success": true,
"date": "2026-06-11",
"base": "MIXED",
"rates": {
"BRENT_CRUDE": 74.82,
"TTF_GAS": 38.15,
"EUA_CO2": 67.40
},
"dates": {
"BRENT_CRUDE": "2026-06-11",
"TTF_GAS": "2026-06-11",
"EUA_CO2": "2026-06-11"
},
"currencies": {
"BRENT_CRUDE": "USD",
"TTF_GAS": "EUR",
"EUA_CO2": "EUR"
}
}

In this response, the success field indicates whether the request was successful, while the rates object contains the latest prices for the requested commodities.

Core Endpoints

1. GET /latest

This endpoint retrieves the most recent prices for one or more symbols.

Key Params: symbols (required), base (optional), category (optional)

curl -G https://energy-api.com/api/v1/latest \
--data-urlencode "symbols=BRENT_CRUDE,TTF_GAS,EUA_CO2" \
--data-urlencode "api_key=YOUR_API_KEY"

JSON Response:

{
"success": true,
"date": "2026-06-11",
"base": "MIXED",
"rates": {
"BRENT_CRUDE": 74.82,
"TTF_GAS": 38.15,
"EUA_CO2": 67.40
},
"dates": {
"BRENT_CRUDE": "2026-06-11",
"TTF_GAS": "2026-06-11",
"EUA_CO2": "2026-06-11"
},
"currencies": {
"BRENT_CRUDE": "USD",
"TTF_GAS": "EUR",
"EUA_CO2": "EUR"
}
}

The rates object provides the latest prices for each symbol, while the currencies object indicates the currency in which each price is quoted.

2. GET /historical

This endpoint allows you to retrieve prices for all symbols on a specific past date. If the date falls on a non-publishing day, it returns the most recent value before it.

Key Params: date (YYYY-MM-DD, required), symbols (required), base (optional)

curl -G https://energy-api.com/api/v1/historical \
--data-urlencode "date=2025-09-15" \
--data-urlencode "symbols=BRENT_CRUDE,TTF_GAS" \
--data-urlencode "api_key=YOUR_API_KEY"

JSON Response:

{
"success": true,
"date": "2025-09-15",
"base": "MIXED",
"rates": {
"BRENT_CRUDE": 71.45,
"TTF_GAS": 36.20
},
"currencies": {
"BRENT_CRUDE": "USD",
"TTF_GAS": "EUR"
}
}

The rates object provides historical prices for the specified date, allowing developers to analyze trends over time.

3. GET /timeseries

This endpoint retrieves historical series between two dates, ideal for charting and trend analysis.

Key Params: start (required), end (required), symbols (required), base (optional)

curl -G https://energy-api.com/api/v1/timeseries \
--data-urlencode "start=2025-01-01" \
--data-urlencode "end=2025-03-31" \
--data-urlencode "symbols=BRENT_CRUDE,TTF_GAS" \
--data-urlencode "api_key=YOUR_API_KEY"

JSON Response:

{
"success": true,
"base": "MIXED",
"start_date": "2025-01-01",
"end_date": "2025-03-31",
"rates": {
"BRENT_CRUDE": {
"2025-01-02": 76.30,
"2025-01-03": 75.90
},
"TTF_GAS": {
"2025-01-02": 46.80,
"2025-01-03": 47.10
}
},
"frequencies": {
"BRENT_CRUDE": "daily",
"TTF_GAS": "daily"
},
"currencies": {
"BRENT_CRUDE": "USD",
"TTF_GAS": "EUR"
}
}

The rates object contains historical prices keyed by date, which is useful for visualizing trends over time.

4. GET /fluctuation

This endpoint provides start and end values, absolute change, and percentage change over a specified period.

Key Params: start (required), end (required), symbols (required), base (optional)

curl -G https://energy-api.com/api/v1/fluctuation \
--data-urlencode "start=2025-01-01" \
--data-urlencode "end=2025-03-31" \
--data-urlencode "symbols=BRENT_CRUDE,TTF_GAS" \
--data-urlencode "api_key=YOUR_API_KEY"

JSON Response:

{
"success": true,
"fluctuations": {
"BRENT_CRUDE": {
"start_value": 76.30,
"end_value": 75.90,
"change": -0.40,
"change_pct": -0.52
},
"TTF_GAS": {
"start_value": 46.80,
"end_value": 47.10,
"change": 0.30,
"change_pct": 0.64
}
}
}

The fluctuations object provides insights into price changes over the specified period, which is essential for traders and analysts.

Real-World Use Cases

1. Price Alert System

Developers can build a price alert system that notifies users when energy prices reach a certain threshold. By utilizing the /latest endpoint, the application can continuously monitor prices and send alerts via email or SMS when predefined conditions are met.

2. ESG Dashboard

Energy companies focused on sustainability can create an ESG dashboard that visualizes carbon intensity data. By leveraging the /carbon-intensity endpoint, developers can provide real-time insights into the carbon footprint of energy consumption, helping organizations meet their sustainability goals.

3. Cost Calculator

A cost calculator can be developed to estimate monthly energy expenses based on current market prices. Using the /cost-estimate endpoint, developers can input user-specific data such as monthly kWh usage and receive an estimated cost based on the latest prices.

FAQ

How often does the TTF gas price update?

The TTF gas price updates daily, reflecting the most recent market conditions. Developers can use the /latest endpoint to retrieve the most current price at any time.

Can I get historical energy prices going back 5 years?

Yes, the Energy API allows you to access historical prices for various commodities. By using the /historical and /timeseries endpoints, developers can retrieve data for specific dates or ranges, enabling comprehensive analysis.

Does the API support multiple currencies?

Absolutely! The Energy API supports multiple currencies for different commodities. Developers can specify the base currency in their requests, allowing for flexible financial calculations and reporting.

Conclusion

In conclusion, the Energy API offers a powerful solution for developers looking to innovate energy billing systems and enhance customer transparency. By providing a unified interface for accessing reliable market data, the API eliminates the complexities associated with traditional data retrieval methods. With its robust endpoints and comprehensive coverage, developers can build applications that meet the evolving needs of the energy sector.

Don't miss out on the opportunity to streamline your energy data integration processes. Try Energy API for free today and experience the benefits of having reliable energy market data at your fingertips.