The first 1kW portable solar pumping station, developed by Nelson Mandela University’s Renewable Energy Research Group (RERG), in collaboration with the merSETA (Manufacturing, Engineering, and Related Services Sector Education and Training), was designed to supply the guesthouse as well as Elisa Namases’ home with enough water for domestic use which included the irrigation of two small vegetable gardens.
According to RERG’s Prof Russell Phillips, the pumping station was fitted with a remote telemetry system which allowed the Mandela University researchers to monitor its performance.
“This pumping station is responsible for much of the greenery that can be seen around the guesthouse as well as maintaining the vegetable gardens which are a primary source of food for Ms. Namases, her extended family, and many of the elderly in the surrounding local community.
“Prior to the installation of the first pumping station in 2018, the family physically carried water from the river for their needs. Based on the success of the initial pumping installation, Nelson Mandela University’s Advanced Mechatronic Technology Centre sought funding from MerSeta for a larger system. This was approved and the installation was completed by the university team in the latter part of September 2020.“
The maximum energy demand for lighting for the guesthouse was calculated to be 1.26 kWh per day. To meet this demand, a 1 kWp PV solar array was installed to charge two 100 Ah deep cycle batteries. To supplement the solar array in charging the batteries, two wind turbines were added. An off-the-shelf horizontal axis wind turbine (HAWT), the ReGen 400W, and an NMU RERG designed custom-built helical savonius vertical axis wind turbine (VAWT) turning a 500W Ginlong generator.
“While the area has a low annual average wind speed it was noted that particularly in summer the region experienced brief, strong nocturnal winds that are expected to supplement battery charging significantly and ensure 24/7 availability of lighting for the Namases-household and guest house.”
Phillips says the primary aim of this project was to provide off-grid power for pumping and lighting to the Damas Guesthouse and a high DNI research test site for the university via a mutually beneficial formal agreement between the family and the University.
According to him, there are numerous secondary spin-off benefits. These include adequate energy and water to allow the family to be self-sufficient, improved quality of life for the family, research test site for Nelson Mandela University with low-cost overheads as well as the transfer of technical and farming skills to the local community with a view to additional similar projects in the region.
As part of the ongoing project, a second research site is located in the Riemvasmaak area earmarked for the solar pump array as well as future Mandela University research projects. The site is roughly 150m from the river, while the hectare of land to be irrigated is approximately 370m from the river.
Phillips says for the university, the next phase of this project is to enclose Research Site 2 which will be used as a storage facility for future projects.
“A communication link between our North Campus in Port Elizabeth and Research Site 2 will also be installed to monitor and receive live data from tests being conducted.”
