Sewage could soon be turned into cylinders of biogas as part of a a city cleanup
ADDIS ABABA, Ethiopia (Thomson Reuters Foundation) – Sewage in Ethiopia’s capital could soon be turned into cylinders of compressed biogas as part of an effort to clean up the city, cut climate-changing emissions and find new sources of clean energy.
Currently the Addis Ababa Water and Sewage Authority (AAWSA) estimates that it collects and treats only 12 percent of the city’s liquid waste. But a new effort to trap sewage and use bio-digesters to turn it into biogas and fertiliser could help lower energy costs, reduce methane emissions from sludge and cut spills, its backers say.
The $18 million project is a joint effort of the city’s water and sewage authority, a non-governmental environmental monitoring firm and 4R Energy, an Ethiopian firm that focuses on recycling and reusing municipal waste for renewable energy.
Benjamin G. Sishuh, 4R Energy’s project manager, said he sees the effort as a way of scaling up small-scale biogas projects that have proliferated in Africa and elsewhere.
“I saw that biogas use in rural or urban area was very small, so I came up with a plan for biogas development that can be used by the majority of the population (and) which can be affordable” said Sishuh. He said his company wants to put the project into effect at two large waste dumps in the city.
The project could be operational as soon as early next year, he said. If successful, it could supply as much as 30 percent of Ethiopia’s compressed natural gas needs, AAWSA estimates.
Ethiopia currently meets its gas demands by importing liquefied petroleum gas (LPG) from countries including Yemen, Sudan and Libya, Shishuh said.
The project is a public-private partnership with environmental non-profit Lem Ethiopia carrying out environmental monitoring and impact assessment, he said.
Sishuh’s company hopes that gas produced by the project will be sold to households for cooking and heating, at prices lower than those families now pay for imported gas. Fertiliser produced from the waste also could be sold to farmers inexpensively, he said.
REDUCING CLIMATE CHANGE, POLLUTION
But city officials are most interested in the project’s ability to reduce methane emissions and local pollution, which is worsening as the capital grows.
Nuri Mohammed, a wastewater treatment manager at AAWSA, said lack of sewage treatment today leads to problems with the safety of drinking water, and could spell outbreaks of diseases such as cholera if not properly dealt with.
AAWSA, which is struggling to keep up with the city’s waste disposal needs, is currently expanding Kaliti wastewater treatment plant in order to increase its capacity by 90 percent, to around 1,000 cubic meters of waste per day by 2016, he said.
Nuri said that as the city tries to cope with a growing number of homes and businesses, the need for proper sewage disposal is paramount and his authority is working on expanding sewer systems to accommodate the flow.
Currently some of Addis Ababa’s sewage is deposited at several dump sites where it is converted into fertiliser for non-edible crops, such as flowers.
Moges Worku, the executive director of Lem Ethiopia, the organisation that will carry out environmental monitoring of the project, said it will have “great impact in cutting greenhouse gases being evaporated from the landfill sludge to the atmosphere”.
Ethiopia aims to become a net zero carbon emitter by 2025 through the use of renewable energy, biofuel and reforestation programmes.
Gebreegzabhir Gebremeksel 33, who owns a small restaurant that employs three staff, said cheap gas is a major attraction of the project. Today he spends on average 20 percent of his income on liquefied petroleum gas, he said.
Each month he spends on average 1,630 birr ($81) on gas cylinders to run his restaurant and his home, a cost on top of feeding his family, paying his workers and paying his rent, he said. Any reduction in the cost of energy would produce welcome savings, he said.
(Editing by Laurie Goering)
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