Neptune 3 Pro
Idle- State
- Printer idle — no print running (saw no print start yet)
- Also watched
- Print Status — a Wyze cam on the Z-axis rail shows the live visual (visual-only): print progress and job state come from OctoPrint, and completion is confirmed by the Shelly plug's power drop.
- Current draw
- 15.3 W · 123.1 V · 0.23 A
- Total energy metered
- 58.70 kWh since plug install · ≈ $4.39 avg per print at $0.1640/kWh + printer & supplies $439.07
- Prints tracked
- 131 start/end cycles at 40 W threshold
- Updated
- 2026-10-14 20:23 UTC · polls every 15 min
Recent print events
- END 2026-10-14 15:37 UTC — ran 15.1 h · 1.74 kWh (≈$0.28)
- START 2026-10-14 00:32 UTC — power jumped to 253 W (heating)
- END 2026-10-13 01:28 UTC — ran 9.3 h · 1.10 kWh (≈$0.18)
- START 2026-10-12 16:12 UTC — power jumped to 275 W (heating)
- END 2026-10-12 08:26 UTC — ran 4.8 h · 0.55 kWh (≈$0.09)
- START 2026-10-12 03:40 UTC — power jumped to 51 W (heating)
- END 2026-10-12 00:10 UTC — ran 4.5 h · 0.54 kWh (≈$0.09)
- START 2026-10-11 19:39 UTC — power jumped to 194 W (heating)
- END 2026-10-11 19:24 UTC — ran 0.5 h · 0.05 kWh (≈$0.01)
- START 2026-10-11 18:54 UTC — power jumped to 305 W (heating)
Recent samples (15-min polls)
| Poll time (UTC) | Instant draw | State |
|---|---|---|
| 2026-10-14 16:37 UTC | 15.3 W | idle |
| 2026-10-14 16:52 UTC | 15.3 W | idle |
| 2026-10-14 17:07 UTC | 15.2 W | idle |
| 2026-10-14 17:22 UTC | 15.3 W | idle |
| 2026-10-14 17:37 UTC | 15.4 W | idle |
| 2026-10-14 17:52 UTC | 15.3 W | idle |
| 2026-10-14 18:07 UTC | 15.4 W | idle |
| 2026-10-14 18:22 UTC | 15.3 W | idle |
| 2026-10-14 18:37 UTC | 15.4 W | idle |
| 2026-10-14 18:52 UTC | 15.3 W | idle |
| 2026-10-14 19:07 UTC | 15.4 W | idle |
| 2026-10-14 19:22 UTC | 15.3 W | idle |
| 2026-10-14 19:38 UTC | 15.4 W | idle |
| 2026-10-14 19:53 UTC | 15.3 W | idle |
| 2026-10-14 20:08 UTC | 15.3 W | idle |
| 2026-10-14 20:23 UTC | 15.3 W | idle |
How this works: a Shelly Plug US Gen4 sits in the printer's power chain.
Every 15 minutes this page polls the plug's cloud API for live wattage. The printer idles around 20 W
(screen + PSU standby); when a print starts, the bed and hotend heaters push the draw above 40 W, and it
falls back below 20 W when the print ends. Because the poll interval is 15 minutes, start/end times are
accurate to the nearest sample (the timestamp shown is when the change was detected, i.e. within 15 min of
the true time). Preheating the bed by hand looks like a print start. Energy comes from the plug's
cumulative kWh counter; energy costs use a 4-month rolling average of SELCO rates
(0.1640/kWh avg; latest bill 2026-09-14; synced daily from the MonthlyObligations
spreadsheet from the 13th on), and printer & supply costs from the printer-supplies spreadsheet are added
on top, spread evenly across every print.
