Vast energy value in human waste

United Nations University – Institute for Water, Environment and Health — Hamilton, Canada

3 Nov 2015

102210Safe, systematic collection of human waste in low-resource countries could yield valuable fuels, invaluable health and environmental benefits

Biogas from human waste, safely obtained under controlled circumstances using innovative technologies, is a potential fuel source great enough in theory to generate electricity for up to 138 million households – the number of households in Indonesia, Brazil, and Ethiopia combined.

A report today from UN University’s Canadian-based Institute for Water, Environment and Health estimates that biogas potentially available from human waste worldwide would have a value of up to US$ 9.5 billion in natural gas equivalent.

And the residue, dried and charred, could produce 2 million tonnes of charcoal-equivalent fuel, curbing the destruction of trees.

Finally, experts say, the large energy value would prove small relative to that of the global health and environmental benefits that would accrue from the safe treatment of human waste in low-resource settings.

“Rather than treating our waste as a major liability, with proper controls in place we can use it in several circumstances to build innovative and sustained financing for development while protecting health and improving our environment in the process,” according to the report, “Valuing Human Waste as an Energy Resource.”

The report uses average waste volume statistics, high and low assumptions for the percentage of concentrated combustable solids contained (25 – 45%), its conversion into biogas and charcoal-like fuel and their thermal equivalents (natural gas and charcoal), to calculate the potential energy value of human waste.

Biogas, approximately 60% methane by volume, is generated through the bacterial breakdown of faecal matter, and any other organic matter, in an oxygen free (anaerobic) system.

Dried and charred faecal sludge, meanwhile, has energy content similar to coal and charcoal.

UN figures show that 2.4 billion people lack access to improved sanitation facilities and almost 1 billion people (about 60% of them in India) don’t use toilets at all, defecating instead in the open.

If the waste of only those practicing open defecation was targeted, the financial value of biogas potentially generated exceeds US$ 200 million per year and could reach as high as $376 million. The energy value would equal that of the fuel needed to generate electricity for 10 million to 18 million local households. Processing the residual faecal sludge, meanwhile, would yield the equivalent of 4.8 million to 8.5 million tonnes of charcoal to help power industrial furnaces, for example.

World already reuses the water and nutrients in wastewater

Says lead author Corinne Schuster-Wallace: “Increasingly, water-scarce regions are being driven to separate and reuse the water in wastewater, particularly to expand marginal agricultural lands. There is a technological opportunity, particularly in rural growth areas and small towns, to derive energy as well from this resource.”

UNU-INWEH Senior Research Fellow Chris Metcalfe of Trent University notes that human waste, as with animal waste, is already used to improve food production in many places around the world, governed by guidelines to ensure its safe use.

A study in Sweden established that human urine contains over 300 g of phosphorous, 900 g of potassium and 300 g of sulphur per cubic meter. According to the World Health Organization, an individual’s body excretes an estimated 4.5 kg of nitrogen and 548 g of phosphorus per year.

“We recycle the nutrients in human waste effectively via agriculture in many places, yet the potential energy value of human waste has been given much less attention to date,” says Dr. Metcalfe, a report co-author along with UNU consultant Chris Wild. “Challenges are many but clearly there is a compelling, multi-dimensional financial case to be made for deriving energy from waste.”

Says UNU-INWEH Director Zafar Adeel: “When it comes to creating misery and poverty, human waste mismanagement has few rivals. If we can demonstrate a simple, cost effective new approach in low-resource settings, if we can successfully make a business case and change the economic paradigm of human waste management, we can advance development, protect the environment and help reduce sanitation problems causing one-tenth of all world illnesses.”

“World Toilet Day, upcoming November 19, offers the opportunity to promote new thinking and to continue puncturing the taboos in many places that inhibit discussion and perpetuate the disgrace and tragedy of inadequate human waste management in many developing world areas. This report contributes to that goal.”

Waste to wealth

With initial seed funds from federally-funded Grand Challenges Canada, UNU-INWEH in partnership with the Ugandan Ministry of Water and Environment, its agencies, and other NGO and academic institutions, established the Waste to Wealth national framework.

Waste to Wealth utilises modern anaerobic digestion technologies linked to sanitation systems.

With a focus on rural growth centers and small towns, as well as high population density institutions such as schools and prisons, the biogas and residual material left from energy conversion is a valuable economic resource to provide a return on investment in bioenergy technologies.

The ultimate goal of Waste to Wealth is decentralised (on site) faecal waste management and to help bridge the finance gap for sanitation in Uganda. By identifying value in waste (energy and /or fertilizer), Waste to Wealth provides an incentive to use toilets and a mechanism to finance both upfront capital costs as well as facility operation, maintenance, and expansion. In addition to the economic opportunities, sanitation interventions have known benefits to individual, household and community health and wellbeing.




Phase two of the project involves proof of concept of a series of proposed initiatives, including equipping a Ugandan prison with a $100,000 system requiring approximately $5,000 in annual operating costs, expected to pay for itself through fuel cost savings within 2 years.

Waste to Wealth is one of several pilot projects in Africa to have received seed grants from Grand Challenges Canada for the systematic collection of waste for processing into a variety of energy or agricultural products.

Related projects in Africa include:


  • Collecting and converting human waste into solid fuel for use by cement plants and other industries
  • Franchising toilets; profitably, safely collecting and removing the waste daily, converting it into fuel and fertilizer, and
  • Collecting human waste and converting it into high quality, emission free bio-charcoal cooking fuel


Production of biogas and organic fertilizer from street waste



The United Nations University Institute for Water, Environment and Health is a member of the United Nations University family of organizations. It is the UN Think Tank on Water created by the UNU Governing Council in 1996. The mission of the institute is to help resolve pressing water challenges that are of concern to the United Nations, its Member States, and their people, through knowledge- based synthesis of existing bodies of scientific discovery; through cutting edge targeted research that identifies emerging policy issues; through application of on-the-ground scalable solutions based on credible research; and, through relevant and targeted public outreach. It is hosted by the Government of Canada and McMaster University.

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Example coverage:

TIME Magazine, USA, “How Poop Can Be Worth $9.5 Billion,” click here

Washington Post, USA, “Burning humanity’s poop could yield up to $9.5 billion,” click here

Discovery, USA, “Will the Future Be Powered by Feces?,” click here

Science Magazine, USA, “Human feces from the developing world could power millions of homes,” click here

Reuters / Thomson-Reuters Foundation, UK, “Power from human waste could light millions of homes-UN University” click hereSpanish, “Energía de desechos humanos podría iluminar millones de hogares: Universidad ONU” click here

Agence France Presse, France, French: “Les excréments humains, source potentielle importante d’énergie,” click hereSpanish: “Excrementos humanos tienen importante potencial como para producir energía,” click herePortuguese: “Estudo aponta potencial energético de excremento humano,” click here; Japanese: “人間の排せつ物で発電、途上国の衛生改善も 国連,” click here

The Guardian, UK, “When will the world wake up to the potential of poo power?” click here

Daily Mail, UK, “Now that’s wind power! Gas from human FAECES could generate electricity for up to 138 million households, report claims” click here

BBC World Service Radio, UK (Science in Action), click here

Chicago Sun-Times, and Sun-Times Network (Seattle WA Sun Times, Jacksonville FL Sun Times, Charlotte NC Sun Times, Columbus OH Sun Times): “Study says world’s human poo worth up to $9.5 billion,’ click here

The Atlantic, CityLab, USA, “The Miraculous Energy Source of the Future: Our Poop?” click here

Huffington Post, USA, “Human Waste Could Light Up More Than 138 Million Homes: Study,” click here

Al Jazeera America, USA, “Human waste could provide power for millions in developing world, says UN,” click here

The Australian, $13bn resource squandered as world wastes value of human dung” click here

Politiken, Denmark, “Københavnerne steger i gas lavet af naboens lort og opvaskevand,” click here

Agencia EFE, Spain, “Científicos proponen aprovechar valor energético y económico de excrementos,” click hereEnglish service: “Scientists propose extracting energy and economic worth of human excreta,” click here

RIA Novosti, Russia, “Топливо из высушенных нечистот принесет миру 10 млрд долларов ежегодно” click here

Science et Vie, France, “Energie: Les Excréments Humains Recèlent d’importantes Quantités de Biogaz Inexploitées,” click here 

CNN en Español, United States, “Excremento humano podría ser la próxima gran fuente de energía mundial, según la ONU,” click here, CNN Greece, “Ενέργεια από περιττώματα,” click here

Global News, Canada, “How human poop could generate power for up to 138 million homes,” click here

La Repubblica, Italy, “Dalle deiezioni umane energia per 138 milioni di case,” click here

Green Report, Italy, “Il valore energetico dei rifiuti umani. Dal biogas del Burkina Faso al Franchising toilets in Kenya” click here

Public Radio International (PRI), USA ” click here

Helsingen Sanomat, Finland, “Ihmisen jätöksistä saisi energiaa miljoonille kotitalouksille,” click here

Yonhap News Agency, Korea, “인류 배설물의 에너지 가치…연간 최대 11조원”, click here

Mental Floss, USA, “Poop Could Be the World’s Next Big Energy Resource,” click here

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Full summary of coverage in 14 languages from 59 countries, click here

News release in full, click here