Home›Energy Consumption›Solar Cannabis Grow Calculator

Solar Cannabis Grow Calculator

Enter canopy area, grow type, and lighting — get annual energy, realistic solar offset, ITC + MACRS incentives, and indoor vs greenhouse energy comparison.

Facility configuration
sqft
cycles/yr
Facility & financial
sqft
hrs
$/kWh
Solar analysis for your cannabis facility
15 kW system — 38 × 400W panels — 14% grid offset
⚡ Reality check: Full grid offset is impractical for indoor grows. Solar offsets 14% of your 170,820 kWh annual demand — constrained by your 37 panel maximum from available roof space. A greenhouse would use ~60% less energy.
Lighting daily kWh225.0 kWh/day
HVAC + dehumid daily kWh240.0 kWh/day
Total annual energy170,820 kWh/yr
Annual electricity cost$25,623/yr
Energy intensity976 kWh/lb produced
Gross annual CO2 footprint66 metric tons CO2/yr
Solar grid offset14%
Annual solar savings$3,614/yr
CO2 reduction from solar9 tons CO2/yr
Gross system cost$42,000
Federal ITC (30%)-$12,600
MACRS bonus depreciation-$10,710
Net cost after incentives$18,690
Payback period (after incentives)5.2 yrs
Link copied to clipboard

How to Use This Calculator

Enter your canopy area and grow type

Canopy area is the actual plant growing footprint — this is also typically the regulated footprint in licensed facilities. Total building footprint is usually 2-3x canopy due to support spaces. Grow type is the most impactful choice: a greenhouse hybrid that uses natural sunlight for the main photoperiod uses approximately 60% less energy than a fully indoor facility of the same canopy size.

Select your lighting and enter your facility details

LED at 30W per square foot is now the industry standard, replacing HPS (50W/sqft) in most new facilities. CMH/LEC at 40W/sqft offers improved spectrum but doesn't match LED efficiency. Enter your available roof or ground area for solar — this limits the maximum system size and is the primary reason full grid offset is impractical for large indoor facilities.

Understand the honest solar offset

This calculator deliberately caps the solar grid offset based on grow type and available space. An indoor cannabis facility consuming 2-3 million kWh/year cannot be fully offset by rooftop solar — the math doesn't work without hundreds of acres of panels. The realistic value of solar for cannabis operations is 10-40% offset, reduced operating costs, strong ROI from ITC and MACRS incentives, and an authentic sustainability narrative.

The Formula

Lighting Daily kWh = W/sqft × Grow Type Multiplier × Area × 15h ÷ 1000 HVAC Daily kWh = (15W/sqft HVAC + 5W/sqft Dehumid) × Grow Multiplier × Area × 24h ÷ 1000 Total Daily kWh = Lighting + HVAC + CO2 (0.2 kW × 15h) Annual kWh = Daily kWh × 365 System kW = min(Available Roof Capacity, Needed System Size) Grid Offset = min(Solar Annual kWh ÷ Annual kWh, Grow Type Max Offset) Annual Savings = Annual Cost × Grid Offset % Net Cost = Gross Cost × (1 − ITC 30% − MACRS ~25.5%) Payback = Net Cost ÷ Annual Savings

The Greenhouse Multiplier reduces lighting to 30% of indoor and HVAC to 60% — greenhouse growers use natural light as the primary source and only supplement with LEDs in early morning/late afternoon. This is why a 5,000 sqft greenhouse needs roughly the same electricity as a 1,500 sqft indoor facility.

Example

Green Valley Cultivation — Medium indoor in Denver, CO

Green Valley operates a 2,000 sqft canopy indoor facility in Denver. They use LED lighting (30W/sqft), run 5 harvest cycles per year, pay $0.13/kWh for commercial power, and have 4,000 sqft of usable roof. Denver averages 5.5 PSH.

Canopy2,000 sqft indoor
LightingLED 30W/sqft
LocationDenver, CO (5.5 PSH)
Rate$0.13/kWh commercial

Result

Daily energy~1,346 kWh/day
Annual energy~491,000 kWh/yr
Annual electricity cost~$63,800/yr
Energy intensity~2,100 kWh/lb
Solar system~149 kW / ~373 panels
Grid offset~30%
Annual savings~$19,100/yr
Gross system cost~$417,200
After ITC + MACRS~$231,000 net
Payback~12 years (after incentives)

The numbers are big but so is the operation. Green Valley's electricity bill of $63,800/year is a significant operating expense — solar offsets nearly a third of it. After ITC and MACRS incentives reduce the net cost from $417K to $231K, the 12-year payback is reasonable for infrastructure that lasts 25+ years. The real upside: if they switched to a greenhouse model, energy consumption would drop ~60%, saving $38,000/year in electricity and making solar nearly irrelevant in scale.

FAQ

Indoor cannabis cultivation is one of the most energy-intensive legal industries. A typical indoor facility uses 2,000-3,000 kWh per pound of dried flower produced. For comparison, an average US home uses about 10,500 kWh per year — a 2,000 sqft indoor facility producing 200 lbs/year would use 400,000-600,000 kWh annually, equal to 40-60 average homes. Per square foot of canopy, expect 0.6-0.8 kWh/day for LED operations and 1.0-1.2 kWh/day for HPS — 24/7, every day of the year.
In practical terms, no — not for large indoor operations. A 10,000 sqft indoor facility might consume 2.5 million kWh/year. To generate that with solar would require approximately 1,700 panels (400W each) covering about 250,000 sqft of roof or ground — far more than most facilities have available. Solar realistically provides 10-35% of indoor cannabis electricity, depending on available space. Full offset requires switching to greenhouse production, where natural sunlight handles 70-80% of the lighting need and solar can cover the remaining electrical loads.
Cannabis businesses face unique federal tax challenges under IRC Section 280E, which disallows most deductions for businesses trafficking Schedule I controlled substances — but solar incentives still apply. The federal ITC (30%) is a tax credit applied directly against federal tax liability. MACRS 5-year depreciation (with bonus depreciation) is a deduction against taxable income. For cannabis operators who are paying federal taxes, these incentives work as designed and can reduce net solar cost by 40-55%. Consult a cannabis-specialized tax professional — the ITC interaction with 280E is nuanced and depends on your entity structure.
A well-designed greenhouse cannabis facility uses approximately 60% less electricity than an equivalent indoor operation. The savings come primarily from lighting: natural sunlight provides the bulk of the photoperiod, with LED supplementation only needed during early morning, late afternoon, and overcast days. HVAC loads are also lower because the greenhouse uses natural ventilation for much of the year. The tradeoff is less environmental control — weather, pests, and seasonal light variation are real challenges. Many commercial operators use a hybrid model: propagation and early veg indoors, flowering in greenhouse, combining the control benefits of indoor with the energy efficiency of greenhouse.
Indoor cannabis production has an extremely high carbon footprint relative to other crops. At the US grid average of 0.386 kg CO2/kWh, a 2,000 sqft indoor facility consuming 490,000 kWh/year produces approximately 189 metric tons of CO2 annually — equivalent to driving 21 million miles in a passenger car. Per pound of flower, indoor cannabis produces 770-1,200 kg CO2, compared to 2-10 kg CO2/lb for outdoor-grown crops. Solar panels reduce this footprint proportional to offset percentage but do not eliminate it for indoor operations. Switching to greenhouse production plus solar is the most effective path to a genuinely low-carbon cannabis operation.

Related Calculators

🍄 Solar Mushroom Farm Calculator
Size solar for 24/7 climate-controlled mushroom operations.
🌿 Solar Greenhouse Calculator
Power grow lights, ventilation, and heating with solar.
💰 Solar Savings Calculator
Estimate annual electricity bill savings from a solar system.
📈 Solar ROI Calculator
Full 25-year ROI analysis with ITC and depreciation.

Embed This Calculator

Free to embed on your website. Just copy this code:

<iframe src="https://solarsizecalculator.com/solar-cannabis-grow-calculator"
  width="100%" height="700" frameborder="0"
  title="Solar Cannabis Grow Calculator"></iframe>