Standalone solar photovoltaic (PV) social enterprise technology SolarTurtle, which provides low-cost energy for remote and unconnected communities, has been profitable and operational for more than two years in various communities, says SolarTurtle inventor, founder and manager James van der Walt.
The system, built within a 20 ft shipping container, with polycrystalline solar PV cells on top and an integrated inverter secured inside, harvests solar energy and stores some of the energy in lead crystal batteries, which do not emit harmful or dangerous gases, overheat or contain dangerous chemicals. The enterprise also provides mobile device charging and microwave-based broadband Internet connections for the community at a low cost.
“The sustainability of the system hinges on whether it can sustain earnings. We have proven this with more than two years of profitable operations at Ngangolwandle Senior Secondary School, 50 km east of Coffee Bay, in the Eastern Cape.”
The two years of operations have also prompted some design changes, adds Van der Walt. “Some of the products have proven to be redundant, while we have also tweaked the way in which the microenterprises provide value for the community users.”
In 2015, the system charged batteries of various sizes that were rented out and recharged for a nominal fee. However, demand for charging mobile devices dramatically overshadowed the use of the mobile batteries, as recharging mobile devices using SolarTurtle suited users better than carrying batteries.
Mobile light-emitting diode lamps for general lighting and studying are still in demand, but the social enterprise has also broadened its services to include entertainment and document printing.
“We charge R5 for people to watch movies and other entertainment at the SolarTurtle while they wait for their devices to recharge. Additionally, the microwave-based Internet connectivity has proven to be popular and SolarTurtle owners or employees report many school children accessing electronic educational materials through mobile devices.”
Among the additional improvements, some still to be field-tested, is the automatic opening or closing of the solar panels, dubbed ‘the AutoTurtle’, Van der Walt quips.
“The SolarTurtles operate in relatively poor areas that are sometimes affected by protests and are often high-crime areas. The operator of a SolarTurtle does not have time to close the panels if a protest starts, but we also want the business to reopen to serve its purpose once the protests pass.”
The automatic opening and closing system uses vibration and wind sensors that also protect it from damage during inclement weather. If specific wind speeds or vibrations are detected, such as stones thrown during a protest, the panels will fold away onto the roof.
Van der Walt says that the SolarTurtles will be used to provide banking services in Mozambique, in partnership with financial services firm Nedbank, as part of a pilot project.
A significant barrier is the cost to register as an Internet service provider (ISP), which is about R1-million per province and unachievable for a social enterprise initiative. Solar Turtle has teamed up with ISP Zenzeleni, which has enabled it to use point-to-point, line-of-sight microwave connections to provide fast broadband for the SolarTurtles.
“The SolarTurtles have proven to be valuable for schools and schoolchildren as they provide key elements to help overcome energy and connectivity constraints.”
Van der Walt says the team is investigating the addition of air-to-water separators to the SolarTurtles, which will be able to produce about 100 ℓ/d of water in ideal conditions.
The new AutoTurtle design won the Inventors Garage competition during the South African Innovation Summit, held in September.