PowerLight

Project PowerLight
Show energy mix of dutch power generation as a pie chart on a LED ring
Status	In progress
Contact	bertrik
Last Update	2022-07-19

The concept

Draw the current dutch electrical power generation-mix as pie chart on a LED ring light, with colors representing fractions of a specific power generation source.

For example:

• yellow: solar
• blue: wind
• red: fossil
• green: nuclear
• grey: other/waste

Power generation data

Information about energy in Europe is collected at the european organisation https://www.entsoe.eu/ . The section about electrical energy is collected in ENTSO-E. Data is available from this platform at a 15-minute interval.

TenneT is the organisation that supplies ENTSO-E with data from the Netherlands.

Information about ENTSO-E generation domain API: https://transparency.entsoe.eu/content/static_content/Static%20content/web%20api/Guide.html#_generation_domain

Power generation categories

The backend uses the following categories

ENTSO-E numbers the production types from B01 to B20 ("PsrType"), how these are filled for the netherlands:

• B01 (biomass): always 0, not useful
• B02: not available
• B03: not available
• B04 (fossil hard coal): useful
• B05 (fossil gas): useful
• B06: not available
• B07: not available
• B08: not available
• B09 (geothermal): not available
• B10 (hydro): not available
• B11 (hydro): always 0
• B12 (hydro): not available
• B13 (marine): not available
• B14 (nuclear): useful
• B15 (other renewable): useful, but what is this?
• B16 (solar): hugely underreported, *not* useful
• B17 (waste): useful
• B18 (wind offshore): useful
• B19 (wind onshore): useful
• B20 (other): ???

The solar power problem

In particular the solar power fraction is incomplete, but also the biomass figures are missing. See:

• https://berthub.eu/articles/posts/dutch-electrical-power-figures-2/ provides a nice overview of the current situation about dutch electrical power generation data
• https://energy-charts.info/charts/energy_pie/chart.htm?l=en&c=NL note how the solar part is tiny, even during the day

There is a model that estimates the solar fraction, also at a regional level, at https://api.netanders.io/, however use of this model requires a paid subscription.

What I'm currently doing for the solar fraction, is to use the ENTSO-E forecast instead of the actual solar numbers reported to them, see yesterday's wind/solar forecast. Perhaps this can also be done for the wind fraction.

Hardware

Parts:

• LED ring light https://nl.aliexpress.com/item/1005003798658173.html
• Wemos D1 mini with an ESP8266

Software

The software consists of two parts:

• backend part that collects the power generation data
• light part that visualizes the power generation as fractions on a LED ring

Backend

Source code: https://github.com/bertrik/energymix-server

Runs as a REST-like resource at http://stofradar.nl:9001/energy/latest (1-minute rate limit)

The backend uses the following categories:

• solar = B16 (from the forecast document)
• wind = B18 + B19
• fossil = B04 + B05
• nuclear = B14
• waste = B17
• other = B15 + B20

Returns a JSON-structure like:

{
  "time": 1657057500,
  "total": 9122,
  "mix": [
    { "id": "solar", "power": 0, "color": "#FFFF00"},
    { "id": "wind", "power": 4, "color": "#0000FF"},
    { "id": "fossil", "power": 86, "color": "#FF0000"},
    { "id": "nuclear", "power": 5, "color": "#FF00FF"},
    { "id": "other", "power": 4, "color": "#444444"},
    { "id": "waste", "power": 1, "color": "#444444"}
  ]
}

• time is a unix time stamp in seconds, representing the end of the 15-minute period that the power figures refer to
• total is the total current electrical power (megawatt), suitable for display (on a numeric display inside the ring for example)
• energymix is an array of power sources, each with:
  • a short unique id
  • most recent known power (megawatt)
  • hex color, for display on the led ring

Light

Source code: https://github.com/bertrik/PowerLight

The Arduino sketch polls the REST API using HTTP every minute.

WiFi is managed by WifiManager. LEDs are controlled using FastLED. JSON content is parsed using ArduinoJSON.