The adoption of a diversification strategy of the energy mix to include low-water consumption technologies, such as floating photovoltaics (FPV) and onshore wind turbines, would improve the resilience of the Zambian hydro-dependent power system, thereby addressing the consequences of climate change and variability. Four major droughts that were experienced in the past fifteen years in the country exacerbated the problems in load management strategies in the recent past. Against this background, a site appraisal methodology was devised for the potential of linking future and existing hydropower sites with wind and FPV. This appraisal was then applied in Zambia to all the thirteen existing hydropower sites, of which three were screened off, and the remaining ten were scored and ranked according to attribute suitability. A design-scoping methodology was then created that aimed to assess the technical parameters of the national electricity grid, hourly generation profiles of existing scenarios, and the potential of variable renewable energy generation. The results at the case study site revealed that the wind and FPV integration reduced the network’s real power losses by 5% and improved the magnitude profile of the voltage at nearby network buses. The onshore wind, along with FPV, also added 341 GWh/year to the national energy generation capacity to meet the 4.93 TWh annual energy demand, in the presence of 4.59 TWh of hydro with a virtual battery storage potential of approximately 7.4% of annual hydropower generation. This was achieved at a competitive levelized cost of electricity of GBP 0.055/kWh. Moreover, floating PV is not being presented as a competitor to ground-mounted systems, but rather as a complementary technology in specific applications (i.e., retrofitting on hydro reservoirs). This study should be extended to all viable water bodies, and grid technical studies should be conducted to provide guidelines for large-scale variable renewable energy source (VRES) integration, ultimately contributing to shaping a resilient and sustainable energy transition.

The drought that occurred in Zimbabwe in 2020 affected the country’s main hydro-power station causing the electricity supply to be less secure and reliable. This challenge resulted in load-shedding, which is not desirable to mining companies that require constant and reliable power for their operations. In that regard, a techno-economic analysis was carried out to assess the potential of integrating concentrated solar power (+thermal storage) and photovoltaics (+battery storage) to supply power at a typical mine in Zimbabwe. Two scenarios were simulated—a base case with no exports to the grid and another case where exports were allowed. The models were evaluated based on the generated renewable energy offsetting the demand from the mine, the energy exported, the grid contribution, the localised cost of energy and the net present value. The results show that the addition of a battery storage system to PV improves the percentage of the load offset by the renewable system and the generated energy by the renewable system by almost double. However, the installation cost, required land, LCOE, and simple pay-back also increased by approximately a factor of 2. The addition of a thermal storage system to CSP increased the generated energy, the capacity factor, and the renewable energy contribution by approximately a factor of 2. However, the land required for development and the installation costs also nearly doubled.

This paper presents a Zambia study case for the application of Osemosys and Flextool. Three scenarios are explored assessing Zambian energy transition outlook (2022 – 2063) which include the business as usual (BAU), integrated resource plan (IRP), and Net Zero prospects to align with agenda 2063 for Africa. The output of Osemosys simulation modelling comprises detailed results providing capacity expansion planning of the generation assets to meet the anticipated demand for a specific range of future years (2022 – 2063). Based on the performance of the energy mix (i.e., hydro, thermal and renewable energy generation projects), the simulation assesses the adequacy of the available assets and identifies new capacity to be added at the least cost. Thereafter, the flexibility of the power system is assessed using FlexTool. To contextualise, FlexTool was used to assess the flexibility of the defined specific year of the capacity expansion plans produced in Osemosys. The writeup delved into analysis of three key assessment indicators for the various scenarios which include cost-effective generation, emissions reduction, and flexibility assessment outcome.

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