Participatory Mapping of Local Green Hydrogen Cost-Potentials in Sub-Saharan Africa (2408.10184v1)

Abstract: Green hydrogen is a promising solution within carbon free energy systems with Sub-Saharan Africa being a possibly well-suited candidate for its production. However, green hydrogen in Sub-Saharan Africa is not yet investigated in detail. This work determines the green hydrogen cost-potential for green hydrogen within this region. Therefore, a potential analysis for PV, wind and hydropower, groundwater analysis, and energy systems optimization are conducted. The results are evaluated under local socio-economic factors. Results show that hydrogen costs start at 1.6 EUR/kg in Mauritania with a total potential of ~259 TWh/a under 2 EUR/kg in 2050. Two third of the regions experience groundwater limitations and need desalination at surplus costs of ~1% of hydrogen costs. Socio-economic analysis show, that green hydrogen deployment can be hindered along the Upper Guinea Coast and the African Great Lakes, driven by limited energy access, low labor costs in West Africa, and high labor potential in other regions.

• The paper presents a comprehensive geospatial analysis that integrates renewable energy, sustainable water supply, and socio-economic data to pinpoint optimal sites for green hydrogen production across 31 countries.
• It employs a multi-step methodology—ranging from land eligibility and hourly energy production simulations to cost modeling—to generate detailed cost-potential curves and benchmark Levelized Cost of Hydrogen.
• Findings indicate that hybrid PV-Wind systems combined with strategic desalination can lower production costs to competitive levels, while also enhancing local socio-economic benefits.

This paper, "Participatory Mapping of Local Green Hydrogen Cost-Potentials in Sub-Saharan Africa" (2408.10184), presents a comprehensive, multidisciplinary analysis to identify promising locations for green hydrogen production across 31 countries in Sub-Saharan Africa. The paper integrates assessments of renewable energy potential, sustainable water availability, local socio-economic factors, and energy system optimization to determine the cost-potential curves and overall feasibility of green hydrogen projects.

The methodology involves several key steps, each contributing a layer of practical information:

1. Land Eligibility Assessment: This step identifies suitable areas for open-field photovoltaics (PV) and onshore wind turbines by applying 33 criteria and buffer distances derived from literature and local stakeholder input. Tools like GLAES and GeoKit are used for geospatial analysis. Practical implications: Developers can use the resulting maps (Figure 6) and country-specific exclusion breakdowns (Figure 4, 5) to understand land availability constraints in specific regions and prioritize sites. Exclusions are driven by factors like woodlands, settlements, agriculture, and protected areas. Geothermal potential was also assessed for Kenya (Figure 7).
2. Renewable Energy Potential Assessment: Hourly energy production simulations (2000-2019 data from ERA5, Global Solar/Wind Atlas via RESKit) determine technical potentials and Levelized Cost of Electricity (LCOE) for eligible land areas (Figure 8, 10). Hydropower potential from existing/planned plants (Sterl et al. data) is also included (Figure 12). Practical implications: The LCOE maps for PV and Wind (Figure 9, 11) provide a crucial input for economic feasibility analysis. Lowest LCOE for PV is in the Sahara and Nama Karoo, while low-cost Wind is concentrated in specific coastal or elevated regions. Hydropower LCOE is often very competitive but site-specific (Figure 13). This data is essential for modeling the energy supply side of a hydrogen production system.
3. Sustainable Water Supply Assessment: The paper quantifies groundwater sustainable yield (GSY) for current and future climate scenarios (RCP2.6, RCP8.5) under different environmental flow assumptions (conservative, medium, extreme) using methods based on Bayat et al. [2023]. It also considers seawater desalination and pipeline transport costs as alternatives. Practical implications: GSY maps (Figure 15, 16, 17, Tables 10-12) reveal significant spatial and temporal variability in water availability. Many high-potential RE regions have limited GSY (Figure 20). While desalination adds minimal cost (~1% of LCOH even in dry inland regions), it requires significant infrastructure investment (new plants, pipelines) and needs careful ecological planning for intake/brine disposal. Sustainable water planning, potentially involving desalination or water imports, is crucial for large-scale projects.
4. Local Green Hydrogen Potential Assessment: Using the ETHOS.FINE framework, regional energy systems are optimized to minimize the Levelized Cost of Hydrogen (LCOH) based on available renewable electricity and water supply options (Figure 21, Table 9). PEM electrolysis and Li-ion battery storage are considered. Local electricity and hydrogen demands (NGFS scenarios) are prioritized before considering export potential (Figure 2, Table 8). Cost-potential curves are generated to show LCOH dependency on production quantity (Figure 23). Practical implications: The LCOH maps (Figure 21) provide spatially resolved cost benchmarks. Lowest LCOH is found in Mauritania (~1.6 EUR/kg in 2050) and the Nama Karoo region. The paper finds that hybrid PV-Wind systems in optimal locations (Figure 24, 26) achieve higher electrolyzer full-load hours (Figure 25), reducing overall LCOH. Batteries were not found to be cost-optimal compared to overbuilding RE or reducing electrolyzer utilization in this broad analysis. The cost-potential curves (Figure 23) are vital for evaluating the economic feasibility of different project scales.
5. Socio-Economic Impact Assessment: Composite indicators assess the potential local impact based on energy access, macroeconomic effects (employment), and other factors (biomass dependence, poverty) (Figure 27). Practical implications: The socio-economic maps (Figure 28, 29, Tables 4-5) help identify regions where green hydrogen projects could significantly contribute to sustainable development goals by improving energy access and creating jobs. Regions around the African Great Lakes, Upper Guinea Coast, Nigeria, and Burkina Faso show high potential impact. Developers should consider these factors for project planning, community engagement, and maximizing local benefits, including training for construction and O&M jobs.

Overall Practical Implications and Implementation Considerations:

• Site Selection: Use the comprehensive geospatial data provided (or accessible via the linked GUI) for initial site screening based on land eligibility, RE potential (quantity and LCOE), and water availability (GSY vs. coastal access).
• Resource Mix Optimization: The paper highlights the benefit of hybrid PV-Wind systems, especially in regions like Mauritania, for achieving lower LCOH and higher electrolyzer utilization. Site-specific hourly simulations are necessary for detailed system design.
• Water Strategy: Plan for water sourcing early. Relying solely on local GSY may limit potential quantity. For large-scale projects or sites with low GSY, seawater desalination combined with pipelines appears economically viable but requires significant infrastructure investment and environmental impact assessment.
• Cost Modeling: Implement detailed techno-economic models incorporating projected CAPEX/OPEX for RE technologies, electrolyzers, storage (if needed for specific demand profiles), and water infrastructure (extraction, desalination, transport). Use the paper's LCOH findings as benchmarks.
• Infrastructure Development: Consider the need for electricity grid connections (especially if RE generation is remote from electrolysis or demand) and water pipelines. Transnational infrastructure projects face political challenges but could unlock potential in landlocked, high-potential regions.
• Socio-Economic Integration: Integrate local socio-economic factors into project planning. Identify regions with high potential for positive impact (Figure 27) and prioritize community engagement, local job creation, and capacity building.
• Regulatory Navigation: Be aware of national land use policies, water rights, and investment regulations. The paper emphasizes the importance of aligning projects with local preferences.

The paper concludes that Sub-Saharan Africa has vast green hydrogen potential (over 400,000 TWh/a), significantly exceeding local demand and allowing for export. Lowest costs (~1.6 EUR/kg by 2050) are competitive globally. While water availability is a constraint, desalination is an economically viable solution. The success of green hydrogen deployment depends not just on technical and economic factors but also on navigating land eligibility, ensuring sustainable water use, building necessary infrastructure, and fostering positive socio-economic outcomes aligned with local visions and development goals. Existing fossil fuel/chemical industries in some countries can provide a foundation for infrastructure repurposing.