Techno-economic comparison of standalone solar PV and hybrid power systems for remote outdoor telecommunication sites in northern Ghana

Telecommunication services have continued to evolve to meet the ever-changing bandwidth demand requirements. The electricity grid network of Ghana is faced with challenges, including low voltages, a lack of quick fault response teams, and the proximity to specific locations. Using diesel generators to address the shortfall in grid supply is expensive and has implications for greenhouse gas emissions. This study evaluated the technical and economic benefits of using a standalone solar photovoltaic (PV) system, hybrid (Solar PV/diesel), conventional diesel generators (DG), and grid extension to power an off-grid outdoor telecommunication site. Power solutions configurations were simulated using hybrid optimization of multiple electric renewables (HOMER). The study found the optimum design to be a standalone solar PV/battery system with 56.3 kW solar PV array and Sixty (60) pieces of 12 V SAGM batteries of 135 Ah. The optimum design had a net present cost (NPC) of US$88,176.00 and a cost of energy (COE) of US$ 0.321/kWh. The COE and the NPC of the optimum system were approximately 50% less than the design with DG only, which could significantly impact service tariff and improve access to digital connectivity. The COE from the solar PV/battery system is not competitive with the grid power supply (COE = US$0.12). However, considering the electric distance limit or breakeven distance of 4.51km for grid extension, the solar PV/battery is preferred. Therefore, the stakeholders in providing power solutions to off-grid locations should consider solar PV technology

Operation and Maintenance of Small-Scale Biogas Digesters: Scoping Review and Bibliometric Analysis of Literature

Biogas technology has matured over the years and is gaining acceptance; however, challenges with optimum operation and maintenance of digesters are a massive hurdle for developing countries that threaten the successful adoption of the technology. The failures of biogas digesters leading to the low diffusion of the technology in developing countries have been attributed to several factors spanning from social to technical. This study employed a scoping review and bibliometric analysis to synthesize literature in the Scopus database to map and discuss scientific knowledge. The synthesized data suggest the need for real-time monitoring systems for the optimal operations and maintenance of small-scale biogas digesters. A bibliometric analysis with the VOSviewer software of the study suggested that there is limited research output from developing countries such as Ghana. It, therefore, necessitates the need for conscious commitments from stakeholders to invest resources to advance research to address the challenge.

A systematic review of the design considerations for the operation and maintenance of small-scale biogas digesters

This review investigates small-scale biogas digesters' design and construction considerations to address biogas digesters' failures shortly after installation. The frequent failures of small-scale or household biogas digesters negatively affect its adoption as a clean domestic cooking fuel in developing countries, affecting the achievement of Sustainable Development Goal (SDG) 7. The study considered Scopus database-indexed peer-reviewed journals published between 2000 and 2022. Selected papers focussed on real-time monitoring, stirring mechanisms, and temperature control systems based on predefined inclusion and exclusion criteria with initial search results of 4751 documents, narrowing to 55 papers. The PRISMA 2020 statement was adopted to conduct the study. The study highlights the importance of incorporating a real-time monitoring system as a design factor in small-scale biogas digesters for successful operation and maintenance. The study's findings may be helpful to practitioners, policymakers, and researchers promoting sustainable energy and waste management solutions in low-resource settings