Vertical farming energy use: kWh per kg, where it goes, and what it costs in India

How much energy a vertical farm uses: kWh per kg benchmarks

The most useful single number is specific energy consumption: kWh of electricity per kg of fresh produce. Miserocchi and Franco reviewed published vertical-farm studies in Thermal Science and Engineering Progress (2025) and found 10 to 18 kWh per kg for lettuce, equal to an energy-use intensity of 850 to 1,150 kWh per m² a year. Lettuce was the crop in most of the studies they could compare. Their technical benchmark for what better equipment and control could reach is 3.1 to 7.4 kWh per kg.

Other sources sit in or near that range. Lovat, Noor and Milo (Plant Physiology, 2025) use data from a large commercial vertical farm (Martin and colleagues, 2023) that works out to about 10 kWh of electricity per kg of lettuce. A 2026 Leiden University model by Meeuws and colleagues put lettuce at 7.83 kWh per kg in its current-technology scenario, falling to 2.31 kWh per kg in its most advanced one, against 3.81 kWh per kg for a Dutch greenhouse.

Where the energy goes in a vertical farm

Lighting is the largest use. Miserocchi and Franco put it at 65 to 85 percent of total energy in current farms. The rest is mostly climate control, which is cooling, dehumidification and air movement, plus smaller loads for pumps, dosing, sterilisation and controls. Meeuws and colleagues found lighting remained the largest energy consumer in every scenario they modelled, while climate-control energy per kg also fell as yields improved.

The two big loads are linked. Nearly all the electricity a lamp uses becomes heat inside the room, and plants release most of the water they take up as vapour. The air-conditioning plant has to remove both, so every watt saved in lighting also saves cooling energy. In hot Indian cities, the cooling share rises in summer because heat also enters through walls and the roof. Insulation, a sealed envelope and running lights at night reduce this extra load.

• LED lighting: 65 to 85 percent of energy in current farms.
• Cooling and dehumidification: removing lamp heat and transpired water.
• Air movement: fans that push air across each shelf to prevent tip burn and disease.
• Pumps and water treatment: circulation, RO, UV and dosing.
• Controls, sensors and backup systems.

Why lettuce needs so much electricity

Plants convert only a small share of light into biomass. Lovat, Noor and Milo estimate the median energy conversion efficiency of vertical farms at about 1 percent, from 0.4 to 1.9 percent across farms, against a theoretical ceiling for C3 plants of about 4 percent. They work out about 250 kWh of electricity per kg of dry plant matter. Lettuce is mostly water, so this becomes the 10-plus kWh per kg of fresh leaves reported by farms.

Light-use efficiency is the lever that moves the number most. Jin and colleagues at Wageningen (Food and Energy Security, 2023) compared 53 vertical-farm lettuce studies and found an average of 0.55 g of dry weight per mol of light, against 0.39 in greenhouses and 0.23 in fields. The best vertical-farm value was 1.63 g per mol. Meeuws and colleagues found that raising light-use efficiency, not cutting the electricity price, gave the largest cost reduction.

LED efficacy and watts per square metre

LED fixture efficacy tells you how many micromoles of light each joule of electricity produces. The DesignLights Consortium's Horticultural Technical Requirements V4.0, effective 18 April 2025, set a minimum of 2.5 µmol per joule for listed fixtures. Kusuma, Pattison and Bugbee (Horticulture Research, 2020) calculated upper limits with current technology of about 3.4 µmol per joule for white plus red fixtures and 4.1 for blue plus red, reduced by about 10 percent when optics protect against water and humidity.

Power per square metre is light level divided by efficacy. ICAR-IARI researchers note that PPFD of 150 to 300 µmol per m² per second is optimal for lettuce under artificial light. At 250 µmol and 2.5 µmol per joule, 250 ÷ 2.5 = 100 W per m² of growing area. At 3.0 µmol per joule, 250 ÷ 3.0 = 83 W. Over 16 hours a day for a year, 100 W is 0.1 × 16 × 365 = 584 kWh per m², which fits inside the 850 to 1,150 kWh per m² total once cooling is added.

Electricity tariffs for vertical farms by state

In India, the tariff category matters as much as the kWh. Maharashtra's regulator, MERC, lists "Indoor Vertical Farming" by name under LT IV(C) Agriculture – Others in its multi-year tariff order of 28 March 2025. For 2026-27, the MERC order of 25 March 2026 in Case 75 of 2025 sets that category at ₹5.61 energy plus ₹1.60 wheeling, or ₹7.21 per kWh, while non-residential LT-II tariffs run from ₹10.11 per kWh for loads up to 20 kW to ₹16.42 per kVAh above 50 kW.

Karnataka's Tariff Order 2025 (KERC, 27 March 2025) charges LT-3(a) commercial users 680 paise per kWh in 2026-27, and its LT-5 schedule, which names green houses, floriculture with photoperiod lighting and tissue culture, charges 440 paise. Tamil Nadu's TNERC order of 30 June 2025 places horticulture under LT III-A(1), at ₹4.95 up to 500 units and ₹7.15 above in a bi-monthly bill, while LT V commercial users pay ₹10.45. Fixed charges, duty and fuel adjustment are extra everywhere.

Electricity cost per kg: the arithmetic

Cost per kg is kWh per kg × tariff. At the benchmark's 10 to 18 kWh per kg and Maharashtra's agricultural tariff of ₹7.21, electricity costs 10 × ₹7.21 = ₹72 to 18 × ₹7.21 = ₹130 per kg. On the small non-residential tariff of ₹10.11, it is ₹101 to ₹182 per kg. On LT-II(B) at ₹13.92, it is ₹139 to ₹251 per kg. These are energy charges only; fixed charges add more, especially for a farm with a high sanctioned load.

Compare that with the price buyers pay. The B2B supplier Hyperpure listed iceberg lettuce at ₹99 per kg on 24 September 2026. At most Indian commercial tariffs, electricity alone costs more than that for each kg of vertical-farm lettuce. This is why energy is the first number to check in any Indian vertical farming plan, and why many farms favour crops such as microgreens and herbs that sell for several times more per kg.

Solar power for a vertical farm: offset arithmetic

Rooftop solar lowers the bill but needs far more area than the farm itself. The Ministry of New and Renewable Energy's rooftop solar FAQ (28 April 2022) states that 1 kWp of panels needs about 10 to 12 m² of shadow-free area and generates 4 to 5.5 units a day on a clear sunny day. Take the 1,000 sq ft, 5-layer farm from our cost article, which uses about 1,80,651 kWh a year.

To cover all of it on sunny-day figures, the farm needs 1,80,651 ÷ (5.5 × 365) = 90 kWp at the high end of generation, or 1,80,651 ÷ (4 × 365) = 124 kWp at the low end. That is 90 × 10 = 900 m² to 124 × 12 = 1,488 m² of shadow-free roof, compared with a farm floor of 92.9 m². Cloudy and monsoon days lower generation further. Solar makes most sense as a partial offset under net metering, sized to the roof you have.

Sunlight plus LED hybrids

A greenhouse or glass-roofed farm with LED top-up uses free sunlight for most of the light and switches lamps on only when daylight falls short. The Meeuws model uses a Dutch greenhouse at 3.81 kWh per kg of lettuce as its reference, against 7.83 kWh per kg for its current-technology vertical farm. In India, where daylight is strong for most of the year, the saving on lighting can be larger, though cooling in summer becomes the main challenge instead.

An ICAR-IARI study (Gavhane and colleagues, Scientific Reports, 2023) grew iceberg lettuce in an indigenous vertical hydroponic system under white LEDs at 200 µmol per m² per second and compared it with the same system without artificial light in a greenhouse. Adding LED light raised fresh weight by 60 percent, and a 16-hour photoperiod gave the best energy use efficiency, 206 g of lettuce per kWh of LED electricity. Stacking under glass reduces light on lower layers, so hybrids usually have fewer layers than sealed indoor farms.

How to reduce vertical farm energy use

Most savings come from getting more crop per photon and fewer watts per photon. Cheaper power helps, but the Meeuws model found biological efficiency moved cost more than the electricity price did. Each step below changes one input in the kWh per kg arithmetic, so you can estimate its effect on your own farm before spending money on new equipment.

• Buy fixtures by measured efficacy. Moving from 2.5 to 3.0 µmol per joule cuts lighting power by (1 − 2.5 ÷ 3.0) = 17 percent.
• Match light level and photoperiod to the crop. The ICAR-IARI study found 20 hours of light at 200 µmol reduced iceberg lettuce weight compared with 16 hours.
• Keep light on leaves, not walls and aisles, with close spacing when plants are young and wider spacing later.
• Run lights at night where time-of-day tariffs discount night power and cooler air helps the AC.
• Insulate and seal the room, and use efficient inverter AC or heat pumps with dehumidification.
• Apply for the correct tariff category and check the fixed-charge basis before choosing sanctioned load.
• Consider a greenhouse or hybrid design where land allows, since sunlight is the cheapest photon.

Energy lessons from farms that struggled

High energy prices have closed or shrunk large vertical farms. Just Food reported on 17 May 2023 that Infarm was leaving Europe, where it began in Germany in 2013, to focus on "regions better suited for indoor farming, with low energy prices and healthy market demand", with its chief executive citing escalating energy prices and tough financial markets. For an Indian plan, the lesson is to test the numbers at a tariff 20 percent higher than today's, and at a yield 20 percent lower, before committing capital.

Designing a vertical farm around its energy use

Garden & Acre's Vertical Farm Setup covers feasibility, design, build, commissioning and first-crop support for rooftops, warehouses, campuses, hotels and cafés, with lighting and cooling sized from the crop's light needs and the local climate. Vertical Farm Consulting reviews energy use, fixture choice and tariff category for farms that are already running, including farms built by others. Both are priced in a written proposal after an initial call.

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