Overview

Dynamic electricity pricing (spot tariffs like Tibber, Nordpool direct) creates 3-8x price variation between cheap and expensive hours. KNX demand response automation shifts flexible loads to cheap hours automatically, reducing electricity bills by 15-30% for homes with EV chargers, heat pumps, and batteries.

Tibber API Integration

Tibber API: GraphQL endpoint 'https://api.tibber.com/v1-beta/gql'. Query 'priceInfo { current { total level startsAt } today { total level startsAt } }'. Authentication: Authorization header with 'Bearer YOUR_TIBBER_TOKEN'. Response: 'level' field = VERY_CHEAP / CHEAP / NORMAL / EXPENSIVE / VERY_EXPENSIVE.

Python Bridge on Raspberry Pi 4

Python bridge runs as a systemd service. Every 60s it queries the Tibber API, maps the level to an integer (1=very cheap, 2=cheap, 3=normal, 4=expensive, 5=very expensive), and writes that integer to KNX GA '8/0/1' (DPT 5.010) via the knxpy library using 'tunnel.group_write(GroupAddress("8/0/1"), DPT5010(tariff_level))'.

KNX Logic Reactions

ETS6 comparator block on GA 8/0/1. When value is 2 or lower (cheap): write SG Ready state 3 (GA 8/1/1 OFF, GA 8/1/2 ON → heat pump raise setpoint 3K), write battery forced charge GA 8/2/1 = ON, enable EV charger GA 8/3/1 = ON. When value is 4 or higher (expensive): SG Ready state 1 block if demand also high, battery discharge GA 8/2/2 = ON.

Nordpool Alternative

Nordpool day-ahead prices are published at 13:00 CET daily. A script downloads next-day hourly prices (no authentication required via public API), sorts by price, and marks the cheapest 6 hours as schedule targets. KNX time switch is programmed at 13:00 daily with the next-day cheap-hour schedule.

Price Visualisation and Annual Savings

Gira X1 server KNX GA reads tariff level → displays colour indicator (green=cheap, amber=normal, red=expensive) on Gira touchscreens in kitchen and living room. Annual saving estimate: 5 kW heat pump shifted to cheap hours 8h/day saves approximately 400-600 EUR/year (Nordic markets). EV charging shifted to night saves approximately 200-350 EUR/year for 10,000 km/year driver.