Vertical Farms and the Price of Electricity

Published October 10, 2026

The Deep Harvest, Chapter 10: The Vertical Farming Graveyard

In March 2025, Plenty Unlimited filed for bankruptcy. The indoor farming company had raised $1.19 billion, and its valuation had fallen from $1.9 billion to $15 million. After the bankruptcy it narrowed to a single crop, strawberries.

A vertical farm grows plants indoors on stacked shelves under LED lamps, with machines controlling the water, heat and air. Plenty was one of several. AeroFarms had raised $238 million when it went bankrupt in June 2023. AppHarvest went bankrupt in July 2023 after its peak valuation of $3.7 billion fell by 99 percent. Bowery Farming had raised $700 million and stopped operating in November 2024. The research behind this chapter counts fourteen indoor farming companies that filed for bankruptcy between 2023 and 2025.

The power bill

A field farm gets its light from the sun. A vertical farm buys it from the grid. Growing a kilogram of lettuce indoors takes 10 to 20 kilowatt-hours of electricity, against 0.3 kilowatt-hours in a field. Lamps use 60 to 80 percent of that energy, climate control 15 to 30 percent, and other systems 5 to 10 percent.

In the UK, at a grid price of 0.25 pounds per kilowatt-hour, the electricity in a kilogram of lettuce cost 3.10 pounds, nearly all of what the lettuce sold for. When the UK price rose to 0.40 pounds in 2023, the energy in each kilogram cost 5.00 pounds, which made growing lettuce effectively impossible. The research puts the line close: a farm that breaks even when power costs 10 US cents a kilowatt-hour loses money at 12 cents.

The building

Before the power bill comes the building. A high-specification vertical farm costs $1,000 to $2,500 per square metre of growing area, about $11 million an acre for a high-tech farm against $6 million for a comparable greenhouse. A small 1,000 square metre farm needs $1 million to $2.5 million before it grows a single plant. The research finds payback usually takes more than 7 to 10 years, and 15 to 20 years for some farms. Some equipment sellers' calculators claim 11 months; the research treats those as sales material.

What clears the bar

Indoors, lettuce yields 80 to 120 kilograms per square metre each year, against 3.9 in a field. Even with that yield and good conditions, energy takes 38 to 45 percent of the selling price. The crops that work are watery, fast-growing and expensive. Herbs sell wholesale for $15 to $25 a kilogram. Strawberries fetch $4 to $8 a pound out of season, against $2 to $3 in season, which is why Plenty chose them.

Wheat, rice and corn fail that test. Dry matter is what is left of a plant once the water is gone, and grain is 80 to 90 percent dry matter. It sells for 12 to 25 US cents a kilogram. The research puts the cost of growing it indoors at about 50 times what it returns. That leaves vertical farming a market of $15 billion to $20 billion a year, 1 to 2 percent of the world's fresh produce.

The lamps are close to their limit

The usual answer is better lamps. Lamp efficiency for plants is measured in micromoles per joule: how much light a plant can use comes out for each unit of electricity going in. The best LEDs now reach 2.7 to 3.0, up from 1.7 for the high-pressure sodium lamps used a decade ago. The physical ceiling is about 3.5 to 4.0. If lamps improved another 25 percent, a farm using 10 kilowatt-hours per kilogram would use 7.5, and at 10 cents a kilowatt-hour its energy cost would fall from $1.00 to $0.75 a kilogram. That helps. Climate control, the other big load, does not improve the same way.

Where the numbers work

The farms that survive sit on cheap power. Geothermal electricity in Iceland costs under 5 US cents a kilowatt-hour, and its farms use the geothermal heat to keep the growing rooms warm. Hydroelectric power in the Pacific Northwest of the United States costs under 8 cents. Farms in the Middle East use solar power and waste heat from oil and gas processing. GoodLeaf Farms, running on hydroelectric power in Ontario, stayed profitable and raised $115 million in 2024. In Keihanna, Japan, Spread pipes in waste heat from a nearby cogeneration plant, which makes electricity and heat together, and uses about 40 percent less energy on climate control.

Money moved the same way. Investment in new farming systems fell 53 percent in 2024, and what remained went to cheap-power regions. Cox Farms bought BrightFarms and Mucci Farms and became the largest indoor farm operator in North America. Singapore backs vertical farms as a matter of food security and accepts paying more for food so it imports less.

The environmental case follows the same power line. A vertical farm uses 1 to 2 litres of water for a kilogram of lettuce, against 250 in a field. On UK grid electricity, though, that kilogram carries 4.71 kilograms of CO2-equivalent, a figure that counts all its greenhouse gases as CO2,, against 0.59 for field lettuce grown in Spain and shipped to the UK. In the same study, the farms grew their plants in casings of jute, a fibre farmed in the tropics, which gave them about twice the land-use impact of a field farm. Only on clean, cheap power such as Iceland's do the money and the carbon both come out ahead.

The same test elsewhere

Vertical farming gives a test: take the cost of one unit at full operating scale, add the price of the energy it eats, and see which customers will pay it. The same test applies outside farming. NuScale's small nuclear reactor design had an estimated capital cost of $5,000 per kilowatt in 2015 and about $20,000 in 2023. Its flagship project, with the utility group UAMPS, was terminated in November 2023 because the member utilities found the costs too high.

The vertical farms that are left grow strawberries and herbs on hydro and geothermal power. The other frontier industries in The Deep Harvest have to pass the same check on unit cost and power price, and the next chapters turn to the permits and insurance that add time and cost to every one of them.

Read more in The Deep Harvest, Chapter 10: The Vertical Farming Graveyard.