Lab

4 min read

Greenhouse Lighting

Lighting is both crop energy and climate pressure. Solar radiation warms the greenhouse faster than the controller can always reject heat, while grow lights help the east-zone hydroponics rack and shelf crops when useful light is low. Verdify tracks the light story as a loop: outdoor solar, indoor lux, transmission through the structure, accumulated DLI, bounded per-circuit trigger bands, firmware readbacks, and supplemental-light circuit runtime.

Open the full live lighting dashboard

Current Light State

These cards are live Grafana panels. If they are unavailable, treat them as the current-light view rather than the proof of the whole lighting story; the seven-day rollups and forecast panels below show whether the room is light-limited or heat-limited.

Light Into The Room

Indoor light is not a simple copy of outdoor light. Polycarbonate diffusion, sun angle, tree shade, greenhouse geometry, and sensor saturation all change what the plants actually see. The indoor LDR is useful for timing and relative changes, but it saturates near bright conditions and is not a calibrated PAR sensor.

The lighting thresholds are exterior-lux thresholds, not indoor PAR targets. The current controller readback is 40,000 lux ON with an 8,000 lux hysteresis band, so the OFF edge is 48,000 lux. Tempest exterior lux can exceed 100,000 lux on clear high-sun samples; lower values on a graph usually mean cloud, shade/sensor geometry, or the panel’s time bucket rather than a full-sun constant.

DLI And Grow-Light Decisions

DLI is the plant-facing summary: how much usable light accumulated over the day. It is not the primary switching rule. The lighting controller targets qualified light minutes: a minute counts once when natural lux is above that circuit’s threshold or the actual switch is on. Grow lights add photons, but they also add electrical load and heat, so their value depends on crop need, time of day, and the resource-use story. The graphs show policy bands and circuit state rather than every internal tunable line.

Circuit Policy And Forecast Bands

The two supplemental-light circuits are tracked separately. Each circuit has its own target qualified-light minutes, local-hour window, natural-light ON threshold, OFF threshold, dwell guards, expected state, observed state, and auto-enable readback. Firmware evaluates those state machines once per minute. For switching, it uses Tempest outdoor illuminance first, falls back to the indoor LDR if Tempest lux is missing, and treats missing light as zero rather than inventing a daylight value.

The forecast-band graph binds the same policy into the future: observed and forecast natural light are compared against the main and grow circuit ON/OFF bands, and expected-on markers show when the controller should supplement daylight. Firmware state and reason fields show the database, dashboard, dispatcher, ESP32, and Lutron state path.

Biological Activity Window

Verdify treats the main lighting runtime as the greenhouse’s global biological activity window. The dispatcher mirrors the main circuit start hour and target qualified-light minutes into firmware activity_* tunables. Direct wetting then uses the same activity window, with zone-specific start offsets and drydown holds.

The panels below are the evidence view for that shared clock: the first panel shows the active lighting/activity policy in the forecast window, and the second shows how direct-wet permission is derived from the activity window plus per-zone offsets and drydown holds. The exact current start, duration, offset, drydown, and minimum-temperature values live in AI Tunables Traceability because those readbacks can change without changing the lighting story.

The activity window is permission, not demand. Lights still follow per-circuit lux/runtime logic, misters still require climate demand, and irrigation/fertigation still require their own schedules. The shared gate keeps light, wetting, fert paths, and drydown aligned without crop-specific firmware logic.

Seven-Day Rollup

The daily rollup is the planning view: was the greenhouse light-limited, did grow lights fill the gap, and did solar timing line up with greenhouse electrical load?

Forecast Context

Solar forecast is a control input. If the next day is clear, Verdify expects heat load and may need shade, venting, mist, or pre-cooling. If the day is dim, the lighting and hydroponics pages become more important. Solar alignment helps offset grow-light cost, but it does not make lighting free: cloudy forecasts, late-day heat, crop DLI needs, and circuit runtime still matter.

  • Climate for how light becomes heat and VPD pressure.
  • Hydroponics for the east-zone crops under supplemental lighting.
  • Resource Use for the solar-aligned power and cost story.
  • AI Tunables Traceability for the bounded lighting-related tactics the AI planning agent can write.