This study aimed to analyzing grid‐connected solar PV in Uganda for viability by evaluating the performance ratio of the already‐installed solar systems, and how flexible is the grid to accommodate more power from solar. The data collected from the solar plants included array size, type and rating of each module, array output, cell efficiency, DC to AC ratio, systems capital cost per watt, annual maintenance cost, inverter size and efficiency, array tilt, records of monthly solar irradiation, monthly energy produced, capital costs, operational costs and cost of a unit supplied to the grid. The System Advisor Model was used to analyze the technical and economic performances of solar plants in Uganda. The projected solar penetration by the year 2021 was 6.1%. The total annual energy was estimated at 69.52 GWh. The capacity factor ranges from 13.1% to 17.5% and a performance ratio of 0.76, and are within the recommended values. The grid was flexible up to 25.8% to accommodate more solar energy without destabilizing the network. It is viable to invest in solar energy since all four plants showed a positive net present value.

Uganda is endowed with a number of energy generation sources, however; these sources are spread out or scattered throughout the country. This makes transmission of power from the generating stations expensive. This paper aims at assessing the possibility of reduced cost through increasing substations instead of electricity generation plants through use of Geo pandas and spatial informatics techniques. Power substation data that included coordinates and power ratings, data for Uganda districts, major roads and towns together with population were imported in the jupyter notebook using python and plotting was done to generate a map of power stations in Uganda. The power generating plants, substation, district and population stored data in jupter notebook was retrieved and visualised in GIS where buffering was done in order to determine the area covered by the substations. The point layer of current power substations and plants was buffered at a defined radius to get the current unserved area scenario map for Uganda. As a result of this preliminary work, specific areas were targeted for investment and optimized supply systems was established, which included proposed new power substations. Four power substations were proposed to serve areas without access to the grid and a map showing new sited power stations in unserved areas (densely populated) was generated. Net present worth method was used in the economic analysis to determine whether it makes economic sense in extending transmission lines to serve places without access to electricity vis a vis constructing more power plants. It was observed that extending the grid to selected substations was relatively cheaper as compared to constructing power plants since the economic analysis showed a positive net present worth of USD 63.6 million. Since Uganda has surplus electricity generated, it is better to invest in the transmission lines to serve areas without electricity.

The increase in crop water stress due to drought variability significantly contributes to crop failure and yield reduction in developing regions. The super-absorbent polymers (SAPs)—agro-hydrogel, are promising eco-friendly solutions to minimize drought stress, improve soil health; the structure in particular, and increase water availability in the plant rhizosphere. Knowledge on the production and application of the agro-hydrogels to improve degraded soils and optimize irrigation water use during dry seasons, is limited in East Africa. In this study, two self-made cellulose-based SAPs were assessed in a pilot open-field experiment to evaluate their soil water retention abilities and irrigation water use for improved crop productivity. The research aimed to answer three major questions: (1) What is the water absorption capacity of SAPs derived from agro-waste products? (2) How do the physical properties of these SAPs influence their effectiveness in retaining moisture in soil? and (3) What is the influence of these SAPs on crop growth and yield? The cellulose-based SAPs were synthesized from sawdust and coffee husks using bulk polymerization and tested for their swelling capability in different aqueous media following the standard procedures. The effectiveness of the SAPs in agricultural applications was evaluated in the pilot open-field experiment with okra plant cultivation at the experimental site of Busitema University, main campus, located in Eastern Uganda. The SAPs were analyzed after several absorption cycles over 60 days, and three treatments defined by different SAPs (from sawdust and coffee) with 50% ET_C, 30% ET_C and control were set in a randomized complete block design (RCBD). The results indicated that SAPs-amended soils (5 g of SAPs on each plant) stored a considerable amount of water (2 L per irrigation) and released it gradually to the plant roots during plant growth. Additionally, the polymer synthesized from sawdust absorbed and retained more water (30%) than coffee husks (10%). Therefore, these results suggest that adopting SAPs could become a climate-smart and sustainable approach to water conservation, improving crop productivity and dryland farming, especially in water-scarce and saline regions.

The generation of biodegradable solid waste and wastewaters is characteristic of all slaughterhouses including the Lira Municipality slaughterhouse (LMS) in northern Uganda. However, the LMS is not properly designed to handle and manage the ever-increasing biodegradable solid waste and wastewater. The wastes discharged from LMS, contain reasonable amounts of paunch, fat, grease, undigested food, diluted blood, suspended material, urine, loose meat and soluble protein. The lack of a properly designed slaughterhouse in Lira Municipality, needed to manage and handle the waste has resulted in the discharge of the waste into the environment, leading to pollution of water sources, outbreaks of diseases, and production of unfavorable odors. The objective of this study was to investigate the biogas potential of the LMS biodegradable solid waste and wastewaters at ambient temperatures. The waste was quantified based on Measurement at the point of generation method. Representative samples were characterized for biogas potential. Five treatments of the waste replicated three times were anaerobically digested in 1500mL batch digesters with a working volume of 750mL. Treatment A contained only the inoculum and inoculum in the other treatments B, C, D, and E was approximately 20% of the volume of the substrate. Substrate: water ratio of 1:1, maintained pH of 6.0- 7.0 and retention time of 30 days were used for the study under ambient conditions. On average, 2,597 L, 40 kg and 502 kg of wastewater, cow dung and punch manure respectively were produced from LMS. The quantity and methane content of the biogas ranged from 1029.6 to 3512.7 ml/gVS and 40.6 to 50.4% respectively. Therefore, slaughterhouse wastes are potential sources of biogas production at ambient temperatures.

Effect of distributed solar energy generation on Uganda’s electricity grid stability