11 KiB
Migrating from Entso-E Prices to EPrices
This document explains the rationale behind EPrices and documents all changes relative to the last public release of the predecessor project, entso-e-prices v4.3.1.
It is intended for users who ran entso-e-prices v4.3.1 and want to migrate their Home Assistant automations, dashboards, and energy configurations to EPrices.
Why EPrices was created
The original entso-e-prices project fetched electricity prices from the
ENTSOE Transparency Platform XML API. That API requires a private token,
has rate limits, and returns data in a complex XML format that required
significant parsing logic and an external helper file (entsoe_http_idf.h).
Additionally, all automation logic (midnight bridge, retry scheduling, NVS
management) was split across external HA automations, making the system fragile
and difficult to maintain.
The goal of EPrices was to:
-
Eliminate the need for a private API token — the Energy-Charts API (Fraunhofer ISE) is public, free, and returns clean JSON. No registration, no token rotation, no rate limit concerns.
-
Move all core logic into the device — midnight bridge, retry scheduling, NVS persistence, and boot recovery all run on the ESP32 itself. No external HA automations are required for any core functionality.
-
Simplify the codebase — the two external helper files (
entsoe_http_idf.handentsoe_storage_v2.h) were eliminated. All logic is now either inline ineprices.yamlor in the single helpereprices_nvs.h. -
Improve sensor clarity and user experience — sensor names were systematically restructured with Today/Tomorrow prefixes, redundant words removed, and diagnostic sensors clearly separated from operational ones.
-
Make the system DST-safe — the original slot arithmetic
(hour × 4) + (min / 15)breaks on DST transition days. EPrices uses UNIX timestamps and binary search throughout, making it fully DST-safe.
Summary of all changes from entso-e-prices v4.3.1 to EPrices v1.0
API
| Item | entso-e-prices v4.3.1 | EPrices v1.0 |
|---|---|---|
| Data source | ENTSOE Transparency Platform XML | Energy-Charts JSON (Fraunhofer ISE) |
| Authentication | Private API token required | No token — public API |
| Data format | XML | JSON |
| Price resolution | 15-minute | 15-minute |
| Base price unit | €/MWh | €/MWh (converted to €/kWh in firmware) |
Project structure
| Item | entso-e-prices v4.3.1 | EPrices v1.0 |
|---|---|---|
| ESPHome node name | entso-e-prices |
eprices |
| Friendly name | Entso-E Prices |
EPrices |
| Helper files | entsoe_http_idf.h + entsoe_storage_v2.h |
eprices_nvs.h only |
| NVS namespace | entsoe2 |
eprices |
| Secret key prefix | entsoe_ |
eprices_ |
| Provider fee / VAT | Hardcoded in lambdas | Configurable via secrets.yaml |
| Core automation logic | Split across external HA automations | Fully on-device |
NVS storage
| Item | entso-e-prices v4.3.1 | EPrices v1.0 |
|---|---|---|
| Storage format | Fixed 96-slot float blobs | Dynamic timestamp + price arrays |
| DST handling | Hour-slot arithmetic (h×4)+(m/15) — breaks on DST |
UNIX timestamp binary search — DST-safe |
| Boot recovery | Via external HA automation | On-device boot_recovery_today/tomorrow_script |
| Midnight bridge | Via external HA automation | On-device midnight_bridge_promotion script |
Fetch scheduling and retry logic
| Item | entso-e-prices v4.3.1 | EPrices v1.0 |
|---|---|---|
| Today fetch trigger | External HA automation | On-device auto-retry (up to 8 attempts) |
| Tomorrow fetch schedule | External HA automation | On-device 13:25 → 13:55 → 14:55 … 19:55 |
| Manual force update | Button | Button (unchanged) |
| Midnight bridge | External HA automation at 00:00 | On-device on_time: 00:00:00 |
Sensor naming
All sensors were renamed with a systematic Today / Tomorrow prefix. The words "electricity" and "energy" were removed from all sensor names. "Next Day" was replaced with "Tomorrow" throughout.
Numeric sensors
| entso-e-prices v4.3.1 name | EPrices v1.0 name |
|---|---|
Current Electricity Price |
Today Current Price |
Next Electricity Price |
Today Next Price |
Average Electricity Price Today |
Today Average Price |
Highest Electricity Price Today |
Today Highest Price |
Lowest Electricity Price Today |
Today Lowest Price |
Current Hourly Electricity Price |
Today Current Hourly Price |
Next Hourly Electricity Price |
Today Next Hourly Price |
Highest Hourly Electricity Price Today |
Today Highest Hourly Price |
Lowest Hourly Electricity Price Today |
Today Lowest Hourly Price |
Current Max Hourly Price Percentage |
Today Current Max Hourly Price Percentage |
Daily Price Update Attempts |
Today API Fetch Attempts (moved to text_sensor) |
Today Entry Count |
Today Entry Count (moved to text_sensor) |
Next Day Current Electricity Price |
Tomorrow Current Price |
Next Day Next Electricity Price |
Tomorrow Next Price |
Average Electricity Price Tomorrow |
Tomorrow Average Price |
Highest Electricity Price Tomorrow |
Tomorrow Highest Price |
Lowest Electricity Price Tomorrow |
Tomorrow Lowest Price |
Current Hourly Electricity Price Tomorrow |
Tomorrow Current Hourly Price |
Next Hourly Electricity Price Tomorrow |
Tomorrow Next Hourly Price |
Highest Hourly Electricity Price Tomorrow |
Tomorrow Highest Hourly Price |
Lowest Hourly Electricity Price Tomorrow |
Tomorrow Lowest Hourly Price |
Next Day Current Max Hourly Price Percentage |
Tomorrow Current Max Hourly Price Percentage |
Next Day Price Update Attempts |
Tomorrow API Fetch Attempts (moved to text_sensor) |
Tomorrow Entry Count |
Tomorrow Entry Count (moved to text_sensor) |
Text sensors
| entso-e-prices v4.3.1 name | EPrices v1.0 name |
|---|---|
ENTSO-E Hourly Prices EUR⁄kWh JSON |
Today JSON Hourly Prices EUR⁄kWh |
ENTSO-E 15-Min Prices EUR⁄kWh JSON (P1 00:00-07:45) |
Today JSON 15-Min Prices EUR⁄kWh (P1 00:00-07:45) |
ENTSO-E 15-Min Prices EUR⁄kWh JSON (P2 08:00-15:45) |
Today JSON 15-Min Prices EUR⁄kWh (P2 08:00-15:45) |
ENTSO-E 15-Min Prices EUR⁄kWh JSON (P3 16:00-23:45) |
Today JSON 15-Min Prices EUR⁄kWh (P3 16:00-23:45) |
Time Of Highest Energy Price Today |
Today Highest Price Time |
Time Of Lowest Energy Price Today |
Today Lowest Price Time |
Time Of Highest Hourly Energy Price Today |
Today Highest Hourly Price Time |
Time Of Lowest Hourly Energy Price Today |
Today Lowest Hourly Price Time |
Price Update Status |
Today Price Update Status |
Last Price Update Time |
Today Data Loaded Time |
Price Update Status Message |
Today Price Update Status Message |
Current Price Status |
Today Current Price Status |
ENTSO-E Next Day Hourly Prices EUR⁄kWh JSON |
Tomorrow JSON Hourly Prices EUR⁄kWh |
ENTSO-E Next Day 15-Min Prices EUR⁄kWh JSON (P1 00:00-07:45) |
Tomorrow JSON 15-Min Prices EUR⁄kWh (P1 00:00-07:45) |
ENTSO-E Next Day 15-Min Prices EUR⁄kWh JSON (P2 08:00-15:45) |
Tomorrow JSON 15-Min Prices EUR⁄kWh (P2 08:00-15:45) |
ENTSO-E Next Day 15-Min Prices EUR⁄kWh JSON (P3 16:00-23:45) |
Tomorrow JSON 15-Min Prices EUR⁄kWh (P3 16:00-23:45) |
Time Of Highest Energy Price Tomorrow |
Tomorrow Highest Price Time |
Time Of Lowest Energy Price Tomorrow |
Tomorrow Lowest Price Time |
Time Of Highest Hourly Energy Price Tomorrow |
Tomorrow Highest Hourly Price Time |
Time Of Lowest Hourly Energy Price Tomorrow |
Tomorrow Lowest Hourly Price Time |
Next Day Price Update Status |
Tomorrow Price Update Status |
Next Day Last Price Update Time |
Tomorrow Data Loaded Time |
Next Day Price Update Status Message |
Tomorrow Price Update Status Message |
Next Day Current Price Status |
Tomorrow Current Price Status |
ENTSO-E Last Reboot |
Last Reboot |
Entso-E Today NVS Status |
Today NVS Status |
Entso-E Tomorrow NVS Status |
Tomorrow NVS Status |
ENTSO-E Last Update Source |
Last Update Source |
Today Data Date |
Today Data Date (unchanged) |
Tomorrow Data Date |
Tomorrow Data Date (unchanged) |
Buttons
| entso-e-prices v4.3.1 name | EPrices v1.0 name |
|---|---|
Entso-E Force Update |
Force Today's Update |
Entso-E Force Next Day Update |
Force Tomorrow's Update |
Entso-E Reboot Device |
Reboot Device |
New sensors in EPrices v1.0 (no equivalent in v4.3.1)
| Sensor | Purpose |
|---|---|
Today Last API Fetch Time |
Timestamp of last successful HTTP fetch for today |
Tomorrow Last API Fetch Time |
Timestamp of last successful HTTP fetch for tomorrow |
WiFi Signal |
RSSI in dBm |
Uptime |
Human-readable uptime string |
Sensor output changes
| Sensor | v4.3.1 output | EPrices v1.0 output |
|---|---|---|
Last Reboot |
Last reboot: 2026-04-04 20:10:10 |
2026-04-04 20:10:10 |
Today NVS Status |
Today NVS: Stored 96 pts for 2026-04-04 |
Stored 96 pts for 2026-04-04 |
Tomorrow NVS Status |
Tomorrow NVS: Stored 96 pts for 2026-04-05 |
Stored 96 pts for 2026-04-05 |
Today Entry Count |
96.0 |
96 |
Tomorrow Entry Count |
96.0 |
96 |
Today API Fetch Attempts |
0.0 |
0 |
Tomorrow API Fetch Attempts |
0.0 |
0 |
Today Current Price Status |
Valid / Missing |
Valid / Missing / Stale |
Today Data Loaded Time |
Stamped on HTTP fetch only | Stamped on NVS load and HTTP fetch |
Tomorrow Data Loaded Time |
Never after NVS boot load |
Stamped on NVS load and HTTP fetch |
HA entity ID changes
All entity IDs changed due to the node name change from entso-e-prices to eprices.
Find and replace in all your automations and dashboards:
sensor.entso_e_prices_ → sensor.eprices_
button.entso_e_prices_ → button.eprices_
Then apply the individual sensor name slug changes from the tables above.
NVS data
The NVS namespace changed from entsoe2 to eprices. On first boot after
flashing EPrices v1.0 the device will not find any stored data and will
trigger a fresh HTTP fetch automatically. This is expected and safe.
No manual NVS erase is required.
Migration checklist
- Flash
eprices.yamlto the device - Update
secrets.yaml— rename allentsoe_keys toeprices_; addeprices_prov_feeandeprices_vat_rate - In all HA automations: replace
entso_e_prices_witheprices_in all entity IDs - Apply individual sensor name slug renames from the tables above
- Remove any external HA automations that handled midnight bridge, boot recovery, or fetch scheduling — these are now all on-device
- Verify the device fetches fresh data on first boot (check
Today NVS StatusandToday Price Update Status Message) - Update any HA dashboard cards referencing old entity IDs