The newly-elected Mayor of Kathmandu Balen Shah has called waste management of the city his top priority. Even before being sworn in, he visited the Sisdol landfill site to see what a challenge he has given himself.
Mayor Shah wants to incinerate segregated waste at the new dumping site in Bancharedanda, and compost the biodegradable garbage into fertiliser to distribute to farmers.
All good ideas, but what the structural engineer/rapper mayor may have missed is the potential to turn the waste also into biogas.
Urban municipalities across Nepal generate over 2,200 metric tons of solid waste a year, 54% of which is organic, and this could generate close to 10,000 metric tons of methane gas. Gasifying just the waste from Kathmandu Valley could produce 1,700 cylinders of bio-CNG daily.
“Given that more than half of Nepal’s municipal garbage is biodegradable, generating bio-CNG in digesters could be the answer to energy self-sufficiency and sustainability,” writes Sushmita Dulal of WindPower Nepal.
She adds: “This is a win-win, it improves the urban environment, reduces carbon emission and slashes the trade deficit by substituting LPG and chemical fertiliser use.”
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Nepal has already demonstrated that it is a pioneer in household biogas, with more than 300,000 digesters in use that turn farm manure into kitchen gas.
The focus has now shifted from domestic biogas to industrial-scale plants for densely populated urban centres. At present, there are 18 commercial biogas plants across Nepal, nine of them under construction.
One of them is Gandaki Urja in Pokhara, the third industrial-scale biogas plant in Nepal and also the largest, with a digester volume of 3,000 cubic metres. It started operations in December 2019, and has been supplying bio-CNG cylinders to big hotels, restaurants, as well as selling fertiliser made from the effluent.
But the lack of raw material (manure and waste biomass) due to minimal waste segregation at the source, Gandaki Urja is having to feed its digesters waste from agriculture and poultry farms and is only generating 1,200 tons of biogas a day.
Half of the plant’s revenue comes from the effluent which is dried and sold as organic fertiliser in farms in Kaski and Tanahu. The plant can produce up to 11,000 tons of fertiliser a year, and while it is nowhere near Nepal’s total demand of 900,000 tons a year, there will be more organic fertiliser when other commercial plants are built.
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Says Kushal Gurung of Gandaki Urja: “Every year Nepal suffers from a chronic lack of chemical fertilisers but it could become a net exporter with a potential of generating 2.5 million tons a year provided that the government prioritises and invests in organic fertilisers.”
The biggest challenge for developers is that LPG gets over Rs1,000 subsidy per cylinder, although the new budget plans to slash the tax rebate.
This means the cost per kg for the bio-Compressed Natural Gas (bio-CNG) has to be the same as that of the LPG regardless of its higher manufacturing cost.
“At the rate our petroleum imports are going up, there is no way we will meet our climate targets but I have not lost hope,” says Gurung. “Turning to biogas is a no-brainer. It will create jobs, convert waste into energy, reduce greenhouse gas emission, as well as generate organic fertiliser which will increase soil fertility.”
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But technological know-how remains a big challenge in scaling up commercial biogas in Nepal. All the machinery has to be imported and in case of repairs or damage, there is no local skill, adding to the cost of operation. Nepal government’s Alternative Energy Promotion Centre (AEPC) has been at the forefront of promoting biogas. Until recently it was also providing technical support and subsidy to industrial plants (up to 40% in machinery) before the World Bank stopped its investment in biogas.
“Biogas is the answer to waste management in Nepal. Increasing job opportunities and reducing our dependence on LPG with this alternative sounds great too but it is not easy to secure funding,” explains AEPC bioenergy expert Sushim Amatya.
If biogas is to substitute a bigger portion of Nepal’s LPG consumption, developers need government subsidies and investment to be directed in the most cost-efficient sectors.
One strategy could be to promote different forms of alternative energies side by side: upgrading Nepal’s electricity infrastructure so that transmission lines can handle increased supply, while also subsidising biogas by slashing the rebate on LPG. Adds Amatya: “Subsidising LPG makes absolutely no sense, it benefits only India and the Gulf. It will definitely not help the climate but renewables also need to be easily available and affordable, the notion of cleaning up the environment alone will not move the general population unless cost-effectiveness is added to the mix.”
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