Why Track Energy?

Electricity is the largest ongoing cost of indoor growing. A single 120x120 cm tent running a 480W LED, inline fan, clip fans, humidifier, and dehumidifier can consume 8–15 kWh per day, translating to $30–$80 per month depending on your electricity rate. Over a 4-month grow cycle, energy costs can exceed the value of the harvest if not managed carefully.

Knowing exactly where your energy goes lets you make informed decisions: Is the dehumidifier running too much? Could you dim the light during the last week? Is it cheaper to run the exhaust at a constant low speed or cycle it on and off?

How GrowVPD Pro Tracks Energy

GrowVPD Pro tracks energy consumption through two methods:

1. Smart Plug Power Reporting

Some Tuya smart plugs report real-time power consumption (watts) and cumulative energy usage (kWh). When a device is connected through one of these plugs, GrowVPD Pro reads the power data directly. This is the most accurate method.

Look for Tuya plugs with energy monitoring in the product description. Not all smart plugs report power — the cheapest models only provide on/off control.

2. Estimated Energy from Nominal Power

For devices that do not report power directly, GrowVPD Pro uses the nominal power rating you enter in the device settings (e.g., 480W for an LED, 250W for a dehumidifier). It multiplies this by the recorded on-time to estimate energy consumption.

For variable-speed devices like fans, the estimation is less precise because actual power at speed 3 is much lower than at speed 10. The app uses a linear approximation based on the speed setting relative to maximum.

Tip: For the most accurate tracking, set the nominal wattage for each device in the device settings. Even estimated tracking is far better than no tracking at all.

Understanding Your Energy Breakdown

The energy dashboard in the Automation tab shows consumption per device, per tent, and per room:

  • Daily kWh: Total energy used in the last 24 hours, broken down by device
  • Device on-time: How many hours each device ran, helping you identify which devices dominate your energy bill
  • Trend over time: See how energy usage changes as plants grow (transpiration increases, dehumidifier runs more, etc.)

Typical Energy Distribution

For a standard tent setup, energy is typically split like this:

  • LED grow light: 50–65% of total energy (the single biggest consumer)
  • Dehumidifier: 15–25% (runs heavily during flower)
  • Inline exhaust fan: 5–10%
  • Humidifier: 3–5% (mostly during seedling/veg)
  • Clip fans, heaters, other: 5–10%

Estimating Costs

Once you know your daily kWh, calculating cost is straightforward:

Daily cost = Daily kWh x Electricity rate (per kWh)

Example: 12 kWh/day at $0.15/kWh = $1.80/day = $54/month = $216 for a 4-month cycle.

GrowVPD Pro's analytics engine can calculate this automatically if you enter your electricity rate. It also factors in the total cost per grow cycle when computing efficiency metrics like cost per gram of dried harvest.

Optimizing Energy Usage

1. Dim Your Lights When Possible

Most modern LED drivers support dimming. Running at 75% power instead of 100% saves 25% of your biggest energy consumer. Many strains do not need full power during the first 2 weeks of flower (stretch phase) or during late flower when the plant is ripening rather than actively photosynthesizing.

2. Right-Size Your Dehumidifier

An oversized dehumidifier cycles on and off frequently, wasting energy on each startup. A properly sized unit runs longer at lower intensity, which is more efficient. See the humidity control guide for sizing recommendations.

3. Use Variable-Speed Fans

Running an inline fan at speed 4 instead of speed 10 can reduce its power consumption by 60–70%. AC Infinity fans with built-in controllers automatically adjust speed based on conditions, running at the minimum speed needed to maintain your target.

4. Schedule for Off-Peak Hours

If your electricity provider charges different rates at different times (time-of-use pricing), schedule your lights-on period during off-peak hours. In many regions, electricity is cheapest between 11 PM and 7 AM. Running a 12/12 flower schedule from midnight to noon instead of 6 AM to 6 PM can save 20–40% on electricity.

Tip: GrowVPD Pro's light schedule feature lets you set precise on/off times for each tent. Pair this with time-of-use electricity rates for maximum savings.

5. Improve Tent Insulation

If your tent is in a cold garage or basement, the heater runs constantly to maintain temperature. Insulating the floor (foam mats), sealing air leaks, and using a more insulated tent shell reduces heating costs significantly.

Comparing Grows by Energy Efficiency

The ultimate energy metric is grams per kWh — how much dried flower you produce for each kilowatt-hour consumed. GrowVPD Pro calculates this automatically when you record harvest data.

Typical ranges:

  • Beginner setup: 0.5–0.8 g/kWh
  • Optimized setup: 1.0–1.5 g/kWh
  • Advanced/commercial: 1.5–2.5 g/kWh

Tracking this metric across multiple grows shows you whether your efficiency is improving and which changes had the biggest impact.