Some 630 million people representing two-thirds of all Africans have no access to electricity, which is identified as a key barrier towards further development. Three main electrification options are considered within our work: grid extensions, mini-grids and solar home systems (SHS). A methodology is applied to all sub-Saharan African countries to identify in high geospatial resolution which electrification option is appropriate taking into account datasets for night light imagery, population distribution and grid infrastructure. Four different scenarios are considered reflecting grid development and electrification constraints due to low population density. The results clearly indicate a dominating role of SHS for achieving a fast electrification of the not supplied people. The share of supplied people by mini-grids is found to be rather low while grid extension serves a large share of the population. The decisive factors for these distinctions are population density and distance to grid. We applied several scenarios and sensitivities to understand the influence of these key parameters. The highest trade-off happens between SHS and grid extension depending on the selected thresholds. Mini-grid deployments remain in the range of 8 to 21%.

The fragile ecosystem of the Galapagos Islands is being affected by population growth, intensive tourism, the exploitation of local resources and the high consumption of imported fossil fuels. This unsustainable development model makes the provision of services such as electricity a challenge. This research investigates the hybrid renewable mini-grid Baltra–Santa Cruz, which represents 62% of the electricity generation mix of the archipelago. This study aims to support the Galapagos Zero Fossil Fuel Initiative and the Sustainable Development Goal 7 through the reduction in diesel consumption and electricity generation costs. To do so, HOMER Pro, a specialized hybrid renewable mini-grid planning tool, is used to perform several techno-economic assessments, focusing on different electricity demand scenarios. Therefore, multiple pathways are compared to identify the most reliable alternatives towards the progressive decarbonization of this hybrid system. The results indicate that installing 18.25 MWp of photovoltaic and 20.68 MWh of battery capacity could reduce the Levelized Cost of Electricity (LCOE) from 32.06 to 18.95 USc/kWh, increasing the renewable energy (RE) share from 18% to 39%. Additionally, the successful application of energy efficiency measures would even reduce the LCOE to 17.10 USc/kWh. What is more, distributed energy is considered the most attractive way to involve islanders in the energy transition process. Finally, this paper offers a comprehensive business model proposal to achieve a resilient energy supply, based on a combination of auctions and energy community models, which demands high political will, reliable and innovative regulations and social awareness about energy use.

Nigeria is the African country with the highest total number of people without access to electricity, at least 90 million. To provide sustainable and affordable energy to these people is an enormous challenge. Advanced modeling and planning are essential tools to enhance the quality of investment decisions. Planning has to address the latest electrification options [grid extension, hybrid minigrids, and solar home systems (SHS)] in a technically and economically sound way for different implementation phases. We have developed a modeling process to derive a least-cost electrification plan for five federal states in Nigeria combining energy system simulations with geospatial information system tools. Investments of approximately $1600 million for medium-voltage (MV) and low-voltage distribution infrastructure, minigrids, and small-scale systems are required to achieve a 100% electrification rate. The simulated electricity system of the five states is characterized by an overall load of about 1804 MW. The electrification options comprise different electrification measures. About 1772 MW are supplied by central power generation through the central grid via 11,579-km new grid lines. The decentralized supply sources include only a few renewable energy (RE) minigrids with a total of 3-MW load will remain isolated, while all others will be interconnected to the central grid. The decentralized supply is defined by 225-MW photovoltaic (PV), 504-MWh battery, and 198-MW diesel-based isolated and interconnected minigrids as well as by 29-MW SHS capacities.