From rubbish to electricity

Construction of the first landfill gas project began at the Robinson Deep site in February, and it was commissioned in May. Work is also powering ahead at the other landfills.
WITH growing concern over shrinking quantities of fossil fuels like coal, oil and natural gas, attention is turning to renewable sources of energy.

Palesa Mathibeli, director of waste managementPalesa Mathibeli, director of waste managementTo this end, the City is working on its plan to convert landfill gas at its five major landfill sites to power thousands of homes around the metropolis.

According to Palesa Mathibeli, the director of waste management in Joburg’s infrastructure and services department, the aim of the project is to mitigate the harmful greenhouse gases emitted from the landfills.

It will take place at the Marie Louise, Robinson Deep, Ennerdale, Linbro Park and Goudkoppies landfills. “We are quite confident that will be able to generate electricity for 20 years or more to about 12 500 middle income households in Johannesburg,” Mathibeli says.

Electricity will be produced through the capture of landfill gas from decomposing rubbish. The gas will be transported in pipes to a conversion plant, where electricity will be produced. The electricity will then be fed into the municipal grid, thus off-setting largely coal derived electricity.

Landfill gas is produced when oxygen mixes with decomposing garbage. This gas is mainly made up of carbon dioxide and methane.

“The benefit coming from the project will be the extraction and elimination of harmful gases that are currently causing bad odours, especially to the surrounding communities of the landfill sites.”

A consortium headed by EnerG Systems was appointed by the City and will meet all the costs relating to the development of the project, right up to the trading of carbon credits and the power that will be generated.

Gas pipes at the Robinson Deep LandfillGas pipes at the Robinson Deep Landfill“The main intention was to appoint a private service provider through a long-term contract to invest in the operation of the project in order to minimise the substantial initial capital investment by the City.”

Mathibeli explains that the project will reduce landfill costs while making the facilities generate additional revenue.

“The extraction and destruction of these gases will provide the City with an opportunity to receive revenue from the generation of emission reductions certificates through the United Nations Framework Convention on Climate Change.”

The project is in support of the South African government’s 2002 accession of the Kyoto Protocol on world climate change, which is a legally binding commitment by developed countries to reduce greenhouse gas emissions.

Mathibeli says landfill gas projects are still in their infancy in Africa, mainly because of their complex nature and the costs of developing them. Research indicates that Africa’s share in the carbon market is only 2 percent with India, South America and Asia dominating the rest of the market.

Bank loan
Mathibeli says the service provider was finding it a challenge to get loans from banks, as they regard clean development mechanism projects as not bankable because of the uncertainty regarding what will happen after the end of the commitment period.

Landfill gas flaring equipmentLandfill gas flaring equipment“The financial institutions view electricity sales from the landfill gas projects as being more bankable and require project developers to have a signed power purchase agreement [PPA] prior to funding approval,” said Mathibeli.

A power purchase agreement is a contract between two parties: one generates electricity for sale and the other buys electricity.

The issue of electricity sales and the signing of PPAs brings another complication in that Eskom is not signing any such agreements with independent power producers, according to Mathibeli.

In spite of the challenges, Mathibeli says the City’s landfill project is moving ahead. “The infrastructural services department together with service provider EnerG Systems have agreed on alternative ways to implement and expedite the project.”

The construction of the first landfill gas project began at Robinson Deep on 21 February and it was commissioned on 23 May. Construction of the Marie Louise landfill gas pipe has started and it will be commissioned in August.

Projects in Linbro Park, Goudkoppies and Ennerdale will be commissioned by June 2012.