Bioethanol: Resources and labour

Land, water, fertiliser and the farm jobs behind each litre

What this tab covers The natural resources (land, water, materials, fuel or feedstock) and the labour needed to capture this energy, per unit, with the reason each is needed.

Ethanol is made from crops, so its main resources are cropland, fertiliser, water and the process heat needed to distil the fuel.

Natural resources

Resource	How much	Why it is needed
Cropland	US corn: 163.96 bushels per acre x 2.76 gallons per bushel, about 4,200 litres of ethanol per hectare (calculated); Brazilian cane yields 78-85 t per hectare¹²	Ethanol comes from sugar or starch that plants make by photosynthesis, so output is limited by crop yield per hectare.
Nitrogen fertiliser	136.5 lb per acre of corn (about 153 kg per hectare, calculated; 2010 survey)¹	Maize needs large amounts of nitrogen to build protein and achieve high yields; making the fertiliser uses natural gas.
Process energy	About 38,141 Btu per gallon at a conventional dry mill; 23,424 Btu per gallon when wet grains are sold¹	Distillation boils off water to separate ethanol, and drying distillers grains evaporates more water; both need heat.
Water	About 21 litres per litre of ethanol at Brazilian mills (2005); crop water footprint of biomass averages 58 m3/GJ in the US and 61 m3/GJ in Brazil²⁹	Mills use water for washing, cooling and fermentation; crops transpire water as they grow.

Labour

Phase	How much	Skills	Why it is needed
Feedstock farming and harvest	Most biofuel jobs are in the agricultural supply chain; in the US 203,600 of 276,100 bioethanol jobs (2023) were indirect supply-chain jobs; Brazil's cane harvest employed about 1.2 million workers in 2005¹⁰¹¹²	Farming, cane cutting or machine harvesting, haulage	Crops must be planted, fertilised and harvested every season, and cane must reach the mill within hours of cutting.
Plant operation	12,800 people at 198 US biorefineries, about 65 per plant (calculated); 72,500 direct US bioethanol jobs (2023)¹⁰	Process operators, chemists, microbiologists, maintenance technicians	Fermentation and distillation are continuous processes needing round-the-clock operation and quality control.
All phases (Brazil)	About 390,560 bioethanol jobs in 2023¹⁰	Agricultural and industrial	Brazil's ethanol industry is integrated with sugar production and still partly manual.

Sources

2015 Energy Balance for the Corn-Ethanol Industry (published February 2016) US Department of Agriculture, 2016
The Sustainability of Brazilian Sugarcane Bioethanol: A Literature Review (Barber, Pellow and de Aragao Pereira, for EECA) AgriLINK NZ / Bioenergy Association of New Zealand, 2008
The water footprint of bioenergy and other primary energy carriers (Gerbens-Leenes, Hoekstra and van der Meer, Value of Water Research Report 29) UNESCO-IHE / University of Twente, 2008
Renewable Energy and Jobs: Annual Review 2024 (2023 data) IRENA and International Labour Organization, 2024
Renewable Energy and Jobs: Annual Review 2025 (Table 1, 2024 employment) IRENA and International Labour Organization, 2025