Vertical Farming Energy Use & Waste Heat Economics

Last reviewed: August 11, 2026

Vertical farming energy use is dominated by LED lighting, which typically accounts for 65–90% of a facility’s total electricity consumption. Of the electricity converted into light, only a small fraction ends up stored as energy in the harvested crop — the remainder becomes heat, which can itself be captured and monetized as a secondary revenue stream, an approach known as vertical farming waste heat recovery.

Key Facts

LED electricity-to-light conversion: Approximately 50% of input electricity becomes photosynthetically usable light (PAR); the other 50% becomes heat directly at the LED chip (Stokes shift and driver losses)
Overall electricity-to-crop-energy efficiency (lettuce): Approximately 1.4% (range 1.1–1.9% depending on facility efficiency) — meaning roughly 99% of electricity used ends up as heat rather than stored plant energy
Specific energy consumption (SEC), lettuce in vertical farms: 10–18 kWh of electricity per kg of fresh lettuce, average 14 kWh/kg
Share of facility electricity used for lighting: 65–90% of total facility electricity consumption, per Miserocchi & Franco (2025)
US DOE finding on LED adoption potential: Full LED adoption in US horticultural lighting could reduce electricity consumption by 34% and save an estimated $350 million annually
US horticultural lighting electricity use (DOE/Navigant, 2017): Estimated at 5.9 terawatt-hours (TWh) annually across US installations
Waste heat recovery rate (transferred from data center liquid cooling analogy): 50–75% of heat generated captured via cold-plate systems at 30–60°C, per industry data center analysis; no vertical-farming-specific recovery rate is yet publicly documented
Worked example: Nordic Harvest (Denmark), 1,000 t/year target output: ~14 GWh/year electricity use; estimated 7,000–9,800 MWh/year of usable captured heat; estimated €59,000–362,000/year in heat sale value; estimated €59,000–441,000/year in avoided cooling electricity costs
Useful temperature range of captured heat: 30–45°C (low-temperature heat), suitable for greenhouse heating, aquaponics/fish farming (24–28°C), mesophilic biogas digesters (35–38°C), or district heating via a heat pump (raised to 60–70°C)

What This Means in Practice

Because nearly all electricity used to power a vertical farm’s LEDs is converted to heat rather than stored in the crop, that heat represents a significant, predictable, and currently underused byproduct. Capturing it at the source (e.g., via liquid-cooled LED boards) provides two separate financial benefits: reduced facility cooling costs, and potential revenue from selling the captured low-temperature heat to a connected use case such as a greenhouse, aquaponics system, biogas digester, or district heating network.

Frequently Asked Questions

How much of a vertical farm’s electricity use goes to lighting?

Lighting typically accounts for 65–90% of a vertical farm’s total electricity consumption.

How efficient is a vertical farm at converting electricity into food energy?

For lettuce, overall efficiency from electricity input to stored energy in the harvested crop is roughly 1.4%, meaning approximately 99% of the electricity used ends up as heat rather than plant energy.

Can vertical farm waste heat be sold or reused?

Yes. Low-temperature heat (30–45°C) captured from LED cooling systems can be used for greenhouse heating, aquaponics, biogas digesters, or fed into district heating networks via a heat pump.

What does the US Department of Energy say about LED lighting in horticulture?

DOE analysis found that full LED adoption in US horticultural lighting could cut electricity consumption by 34% and save an estimated $350 million annually.