From research to implementation – Generating clean energy from pressurised water conduits
A breakthrough development in the application of research outputs funded by the Water Research Commission (WRC) is being realised. Based on studies undertaken by the University of Pretoria (UP) in partnership with The City of Tshwane, the first pilot of a turbine (a rotary engine that extracts energy from a fluid flow and converts it into useful work) in a pressurised water distribution system (pressure hydropower – PHP) in order to generate clean energy is being launched. The PHP system has been installed and integrated at the new site, Pierre van Ryneveld reservoir, built to augment the capacity of the existing water system and located in the south-eastern part of the City of Tshwane. When operational, the system will generate about 16 kilowatts of electricity per hour.
The PHP will provide the City of Tshwane with additional power to utilise for security fencing, alarms and cameras, as well as communication and general maintenance. The reservoir needs to have electricity to monitor the water level and to communicate this data on a 24-hour basis within a control room. Electricity is also needed for lightning at night for safety reasons. Electricity generated here will also be used for pressure management systems. Prof. Stefanus van Vuuren, the lead researcher, says: “the potential exists using PHPs also to tap into a level of pico hydropower generation which will benefit rural communities where communication to the world is a primary concern; the first indications are that some energy will be generated from the low flow rate and low head tapped from water supply. In these cases it will be possible to charge batteries and cell phones.”
Mr Jay Bhagwan, who managed the study, says “The Water Research Commission welcomes this innovative application of research which is demonstrating power generation using closed-conduit pressurised systems. We congratulate The City of Tshwane for exploring the potential of installing PHPs in a number of specific locations in its water networks, where large amounts of pressure and flow can be converted to clean energy”.
Prior to establishment of the Pierre van Ryneveld reservoir, the UP, through funding from the WRC, installed a test PHP at Queenwood Reservoir, also situated in the Tshwane area. The PHP system receives its water from Rand Water at a pressure of up to 250 m. The demonstration of the PHP technology at this location proved to be a huge success for the Tshwane Municipality.
Adriaan Kurtz, of Water and Sanitation at the City of Tshwane, says: “We see this as renewable energy and forms part of the objectives of the City of Tshwane to be a world leader in terms of its programmatic approach to the clean development mechanism (CDM). With COP17 now staged in South Africa from 28 November 2011 to 9 December 2011, the City of Tshwane has uniquely showcased the potential for alternative energy generation.”
The WRC studies indicate that PHPs have huge potential for complementing the energy needs of municipalities. Scoping studies conservatively indicate that by introducing PHPs into the reservoir outlets of the Metros in South Africa, some 26 000 MW/h can be generated immediately. Says Bhagwan, “if this was expanded on a wide scale to large pressurised transfer pipes and reticulation systems, a significant amount of clean energy can be generated to complement the municipalities and country’s needs”. Further demonstration PHPs are planned for Bloemwater, eThekwini Metro Water Services and Rand Water in the coming months.
PHPs have many benefits for the future, from supplying remote communities with electricity to supplementing the energy needs of municipalities.
Contact: Mr Jay Bhagwan
Director: Water Use and Waste Management
Tel: 012 330 9042
Cell: 083 290 7232