EghtesadOnline; Tehran Water and Wastewater Company, a subsidiary of the National Water and Wastewater Engineering Company of Iran (Abfa), and state-owned Renewable Energy and Energy Efficiency Organization, aka Satba, signed a long-term agreement based on which the former will sell electricity generated with sewage to the latter, deputy operations manager at TWWC said Saturday.
"TWWC will supply 500 billion kilowatt hours of electricity generated from biogas to Satba over the next 15 years," Abbasali Moserzadeh was quoted as saying by IRNA.
Each kilowatt hour will cost the equivalent of 5 cents.
According to the official, TWWC runs Iran’s sole biogas power plant, in the South Tehran Wastewater Treatment Complex.
Electricity generation from Tehran wastewater started in 2018 and similar projects are planned in other metropolises including Esfahan, Shiraz and Tabriz.
“The biogas power plant, equipped with combined heat and power (CHP) systems, has the capacity to generate 44,000 megawatts per year and 1,400 terajoule of heating energy, equivalent to energy produced by burning 100,000 barrels of oil or 400,000 cubic meters of gas.”
The plant’s output is sufficient for 40,000 households and it also helps reduce greenhouse gases by 150,000 tons per year.
A biogas plant is a decentralized energy system (connected to a CHP system), which helps self-sufficiency in heat and power needs, and curbs environmental pollution.
Energy from biomass makes a tremendous contribution to sustainable power supply, Moserzadeh said. He did not elaborate. Currently biogas offers the highest user benefits and best use of the energy potential of biomass.
Biogas is produced from the anaerobic fermentation of organic material in the fermenter of a biogas system. Biogas, consisting primarily of methane and carbon dioxide, is created during the anaerobic decomposition of organic waste materials. This gas has a methane CH4 content from 45 to 70%.
During its combustion, it only releases as much CO2 as the plants absorbed during their growth.
Referring to the advantages of biogas-generated power, the TWWC official noted that cogeneration power plants that produce electricity from biogas prevent emissions that would otherwise be released by fossil fuels.
Instead of allowing uncontrolled decomposition of such waste and the release of toxic gases into the atmosphere, they are contained in an oxygen-deprived environment such as a covered lagoon or aboveground steel tank.
From there, methane is extracted and burned to generate electricity or heat.
Satba says Iran has the capacity to generate more than 10,000 MW of electricity from biomass, with 25 cities capable of generating at least 400 MW of electricity from waste material.
Biomass is the largest global source of renewable energy, and contributes an estimated 10% to global energy production, in particular as a direct source of industrial and domestic heat.
An average 20 million tons of waste is produced every year in Iran, and 100 tons of waste is required to run a two MW power plant on a daily basis.
Incineration plants, also known as waste-to-energy (WTE) plants, can reduce CO2 emissions by 50,000 tons per year, whereas a wind plant with the same capacity can cut CO2 emissions by 5,000 tons at the most, Satba said.