ComEd Hourly Pricing as Calendar Events

ComEd electricity prices change every hour — sometimes swinging several cents between midnight and mid-afternoon. After enrolling in hourly pricing, I realized I didn’t want to check a dashboard to know when power is cheap. I wanted to see it on my calendar, right next to the rest of my day.

Same impulse that led me to build iCal feeds for my entire blog history. A calendar is the tool I already use for planning around time. Price data is time data — it just happens to come from a utility instead of a CMS. If I can see that electricity drops to near-zero at 2am and spikes at 6pm, I can plan around it the same way I plan around meetings.

So I built a small Val.town server that generates an iCal feed of price changes. It pulls the last 24 hours of 5-minute prices from ComEd’s public API, averages them into hourly buckets, and grabs the next day’s prices from their (undocumented) day-ahead endpoint. Then it compares consecutive hours and emits a calendar event whenever the price shifts by more than a threshold:

↑ 3.7c/kWh (+0.9c)
↓ 2.1c/kWh (-0.3c)

Stable hours produce no event — gaps in the calendar mean the price isn’t moving. The sensitivity, lookback window, and lookahead are all configurable via query parameters, so I (or you!) can tune it to only surface the swings I care about.

The next step is pairing this with batteries to buffer my high-draw appliances — grow lights, the computer desk — into cheap hours automatically. For now, just seeing the price rhythm on my calendar alongside everything else is enough to shift my habits. Everywhere a calendar.