Johannesburg - In a move to curtail the impact of load shedding, the City of Joburg hopes to harness electricity from water flowing through our water pipes.
The city, through its utility Johannesburg Water (JW), could install turbines in its existing water pipes in an effort to generate additional power to avoid load shedding.
JW estimates that by doing this it could generate between 1 and 2 megawatts of power – or about 10 percent of the agency’s current 21MW requirement.
This technology would complement JW’s biogas-to-energy programme under way at its wastewater treatment plants and augment its renewable energy generation footprint.
The municipality is considering piloting the technology to promote renewable energy generation, mitigate greenhouse gas emissions and load shedding, and take advantage of low-cost energy.
A city delegation, led by mayor Parks Tau, recently returned from a three-day visit to Portland, Oregon, during which it evaluated the feasibility of an in-pipe hydropower system.
The visit showed there is a compelling case for such technology, said JW managing director Lungile Dhlamini, who accompanied the mayor.
“I was initially a little sceptical, but I am now convinced it can work. We are looking at starting a pilot project that could give us about 10 percent of our current needs,” he said.
Dhlamini said that in numerous areas within the city’s water network, JW needs to install pressure-reducing valves.
“By installing the turbines within the water pipes, the utility will be able not only to avoid the cost of installing these pressure-reducing valves but will also be able to harness renewable energy to produce electricity as an added benefit,” he said.
The turbines are installed inside the pipes and turn as the water flows through them, generating electricity as they do, but they must be installed close to an electricity grid connection.
Dhlamini said JW would engage Eskom and City Power to help it locate these connection points.
“We are planning to start small to see how it goes and will be calling for either expressions of interest or requests for proposals, depending on our initial feasibility study. We are in the process of obtaining further technology clarifications from our counterpart, the Portland Water Bureau,” he said.
“Johannesburg Water has estimated it would cost about R23 million/MW. When compared to other renewable energy sources, the in-pipe turbine is comparable to the cost of solar power,” Dhlamini said.
In terms of project development and implementation, the utility is planning to start with actual construction in the second or last quarter of the 2015/16 financial year following engineering, design and procurement processes.
“With help from internationally renowned systems engineer Professor Gunter Pauli and a network of 130 international experts, the idea of in-pipe turbines emerged from the city’s basket of Blue Economy initiatives designed to transform local resources’ scarcity to abundance, while creating business and job opportunities for small to medium enterprises and its job-seekers respectively,” said Dhlamini.
During their visit, the Joburg delegation met with Portland officials, including mayor Charles Hayles, representatives of the Lucid Energy company and other experts linked to the installation of the hydrokinetic in-pipe turbine system in the state of Oregon.