No Bull: Nepal’s Biogas Revolution Reaches a Turning Point
- Manish Koirala
- Jun 9
- 6 min read
Updated: Jun 12
As Nepal’s biogas systems become obsolete after decades of widespread adoption efforts, communities are being forced to switch back to natural gas and firewood, pushing back the country’s renewable energy goals.
In the household of Dipak Regmi, no one has burned petroleum-based fuels or firewood to cook in 18 years — all thanks to a nifty machine that converts human and livestock waste into fuel.
In an agro-economy like Nepal, where more than half of all households raise livestock, biogas digesters were seen as a revolutionary way to tap into renewable energy, addressing the dual problems of waste management and electricity crisis. For families, it meant lighter expenses in the kitchen; for forests, a chance to breathe and stand tall.
Domestic biogas systems are widespread across Asian countries, and Nepal has been an advocate of this technology. But that reputation appears to be shifting: many poor families either can’t afford this technology or don’t own cattle to operate it. “Households that are well-off are quick to acquire this new technology, whereas others are more reluctant,” said Dr Narayan Adhikari, deputy executive director at the Alternative Energy Promotion Center in Nepal.
Between 1992 and 2011, the Himalayan country installed 260,000 domestic biogas digesters in a collaborative effort between the governments of Nepal and the Netherlands. These digesters convert organic matter such as cattle and human waste into methane gas, which can be used to light stoves or power electric bulbs.
Dipak Regmi’s household is among the few in Ward-11 of central Nepal’s Dhulikhel region that have consistently used the biogas digester. In the past, Regmi mostly fed cattle manure into the digester — now, the household relies solely on blackwater from the toilets. The digestate flows out from the end of the system, conveniently placed to spray as fertilizer in their garden.
As people migrate to urban areas in search of a better lifestyle, cattle-rearing, prevalent in rural Nepal, is declining. “Many are headed to Gulf countries for work, and those with better resources are migrating to the US and Canada,” Adhikari said.
As a result, three decades in, biogas’s impact on the country remains up in the air.
Despite the efforts, the use of liquified petroleum gas cylinders in Nepali households has doubled in the last ten years, Adhikari said, with more than 40% of households now relying on gas cylinders. Nepal’s heavy reliance on liquified petroleum gas imports from India poses energy security risks, especially considering India’s history of trade blockades that have disrupted Nepal’s fuel supplies.
Biogas digester systems are fed by cattle dung and gray water from toilets. Although it also depends on the weight of the cows, the excreta of two cows — about forty to fifty kilos — is enough to produce sufficient gas to cook daily meals for a family of four,” said Bashu Gautam, a Nepali doctoral student studying renewable energy technologies at the University of Saskatchewan in Canada.
The leftover digestate from biogas systems is an efficient fertilizer. “When we applied the digestate, the spinach used to grow so thick that it would cover people up,” Regmi said.
A 2020 study showed that the amount of gas produced from biodigesters is impacted by factors such as “fodder availability, livestock herding hours, quality of dung, and seasonal variations.” Despite rearing more cattle per household in the mountains, the total dung produced there is only about thirty percent of the amount produced by cattle in the hills and lowlands – a factor that has a direct effect on the lower biogas usage in Nepal.
Biogas reduces the burden of collecting fuelwood and preparing dung briquettes — tasks that are often shouldered by women and children in rural Nepali households. A family using a biogas digester saves around one full-grown tree each year by avoiding the need for 150 stacks of firewood, which would otherwise be consumed for daily cooking.
“Nepal has the potential for two million biogas plants, yet only around 450,000 have been installed so far,” Krishna Prasad Dhakal, managing director of KP Business, said.
Research shows that using livestock manure, Nepal has the potential to produce over 3,000 million cubic meters of biogas per year, equivalent to 110 million gas cylinders.
A family that uses a biogas digester over liquified petroleum gas can save up to 15,000 Nepali rupees (equivalent to $111 USD) annually by avoiding the use of gas cylinders for cooking.
The ones mostly left behind at Regmi’s village are the elderly, who struggle to raise cattle or maintain a biogas system. “For two elderly people living together, a cylinder will suffice for two to three months,” he said. “It’s not that this technology is no longer useful; it’s just that the elderly can’t, and don’t, raise cattle anymore.
Biogas digesters come with their own issues, aside from requiring more maintenance as they get older.
Hydrogen sulfide gas from biogas stoves can react with zinc roofing — which is common in rural Nepali homes — forming sulfuric acid. The acid corrodes roofs and adds repair costs. Inhaling the gas in high concentrations can also cause vomiting, but installing filters in biogas digesters can prevent such corrosion, Gautam said.
Maintenance is a major issue with most household biogas digesters. “Fifty to fifty-five percent of all the biodigesters tend to become non-functional after installation,” Gautam said. Inside the digester, there are bacteria that help break down organic material, so it’s crucial to ensure that no chemicals, pesticides, or the waste of sick cattle enter the system. “If that happens, the inner biological processes get disturbed, and the gas output drops,” Gautam said.
A 2022 study assessed the condition of household biogas digesters in Kavre district to show that approximately 55% of the mixtures fed to the digesters didn’t yield any biogas, while 18% of the digesters were entirely non-functional.
Yet, Dhakal advises people relocating to urban areas to opt for a biogas digester instead of a septic tank in their new homes, due to the numerous benefits of the former. Working in the research and development of the renewable sector, Dhakal facilitated the installation of more than four thousand household digesters across the country. “Even a layman can operate the digesters effectively with the proper technique,” he said.
“Subsidies were never declared to be a hundred percent—it was just a pilot.”
To make Nepal energy-independent, experts recommend exploring energy mix models and sensitisation programmes on biogas adoption, as well as promoting uptake in portable biogas models.
“We need to utilize solar, biogas, and wind energies,” Gautam said, stressing electric cooking options as another versatile energy source for Nepali households.
Prakash Kiran Jung Thapa, program officer at Wildlife Conservation Nepal, has started a biogas digester project to make the product cheaper and the installation process easier for low-income communities in Nepal, who couldn’t afford gas cylinders. “Previously, they had to light up a raging fire to start cooking their meals, but now with a biogas system installed at their home, they can switch on the stove with just a snap of their fingers,” Thapa said.
Thapa’s project, supported by a German donor and small grants, is in its final stages of installing two hundred household biogas digesters — each four cubic meters in size — for the families of Kailali District. “There is a trend of people shifting to urban areas from rural villages and consequently raising fewer cattle. Thus, four-cubic-meter-sized digesters are sustainable. If tomorrow their cattle number decreases to two or just one, and their toilet is also connected, then that would sustainably keep running,” he said.
His team is also providing the necessary training to local people and biogas users to ensure their systems continue running smoothly post-installation.
Household biodigesters come in varying sizes and models. GGC 2047, a fixed-dome digester model, is one of the initial designs to have been installed in the majority of households. Additionally, a new portable digester model made of plastic called Homebiogas, developed by an Israeli company, is also gaining traction in Nepal.
For families like Regmi’s, biogas wasn’t just a fuel — it was a milestone. They dug the pits, sourced the materials, and made it work with limited help from the government. Across Nepal, many still recall this shift as a proud chapter.
But today, as adoption of this crucial technology slows down, it is clear that the biogas story needs a revival. A revival that can happen with the support of the Nepali government, civic groups, and innovation by concerned citizens.
CORRECTION JUNE 12th: A previous story used an incorrect technical term to describe wastewater from toilets.
Niroj Subedi contributed reporting to the story.
