混合微电网和孤立电网中的可再生能源_经济效益和商业案例（英文版）_90页_8mb

Summary of Renewable Energy in Hybrid Mini-Grids and Isolated Grids: Economic Benefits and Business Cases

Core Content

This report provides an in-depth analysis of the economic and financial viability of renewable energy-based hybridisation in existing diesel mini-grids and isolated grids across seven countries: Colombia, Dominican Republic, Kenya, Indonesia, Philippines, St. Vincent and the Grenadines, and The Gambia. The study evaluates the potential cost savings and benefits of integrating solar photovoltaic (PV) systems with diesel generation, highlighting how hybrid systems can reduce electricity generation costs and improve energy access in remote and rural areas.

Main Points

1. Hybridisation Potential

• Cost Reduction: Hybridisation can reduce average generation costs by 0.3 to 8% at five of the seven sites, even with private-sector financing.
• Public Funding Advantage: When financed with public funds at a 5% real discount rate, hybrid mini-grids can achieve up to 16% cost reductions, with PV contributing 31–40% of total electricity.
• Diesel and PV LCOE: Diesel-only LCOE ranges from 31 to 44 US cents per kWh, while PV LCOE ranges from 16 to 23 US cents per kWh. Hybrid LCOE is a weighted average of both, with PV covering 30–40% of total demand.
• Diesel Savings: Hybrid systems can lead to diesel savings of 20–30% in the base case, depending on the site.

2. Key Factors Influencing Viability

• Plant Size: Larger plants benefit from economies of scale, reducing fixed costs per unit of electricity.
• Diesel Prices: Higher diesel prices increase the cost savings from hybridisation.
• Solar Radiation: Higher solar irradiance enables more PV generation, which is cheaper than diesel.
• Demand Patterns: Residential demand peaks in the evening, when solar is unavailable, meaning diesel remains critical for base-load generation.

3. Financial Viability

• Ownership Structures: Two main ownership models are considered:
  • Public Sector: Assumes lower return expectations (15% on equity, 8% on debt), with concessional debt and utility balance sheet financing.
  • Private Sector: Assumes higher financing costs, which can burden hybrid projects and reduce cost savings.
• Discount Rate and Financing Costs: A flat 5% discount rate is used in the public sector scenario, while private sector scenarios may have higher financing costs.
• Sensitivity Analysis: Highlights the impact of diesel price fluctuations, financing costs, PV penetration levels, and demand growth on the economic viability of hybrid systems.

4. Economic and Financial Models

• LCOE (Levelised Cost of Electricity): Used as the primary indicator for economic viability.
• Base Case: Excludes demand growth and considers EIA reference oil price developments.
• Growth Case: Includes demand growth, which increases generation costs but still supports hybrid viability.
• Assumptions: Includes capital and operational expenditures, debt service cover ratios, and tax rates specific to each site.

Key Sites and Their Characteristics

Recommendations and Outcomes

• Regulatory Support: Regulators and governments must initiate hybrid projects and establish suitable PPA frameworks.
• Public Sector Involvement: Public sector ownership and financing can lead to more viable hybrid projects due to lower cost expectations.
• Private Sector Role: Private sector involvement is crucial for capital-intensive hybrid projects, especially in regions with high diesel prices.
• Need for Detailed Analysis: Before initiating hybrid projects, detailed cost and demand analysis is essential to ensure accurate comparisons and informed decisions.
• Future Scenarios: The report outlines a third scenario for interconnecting isolated grids with national grids, particularly for areas with low on-grid generation costs and no geographical barriers.

Conclusion

Hybridisation of diesel mini-grids with renewable energy, particularly solar PV, presents a viable and cost-effective solution for improving energy access and reducing environmental impact in remote areas. The economic benefits are most pronounced in sites with high diesel prices and sufficient solar radiation. While the financial viability of hybrid projects depends on ownership and financing structures, the study underscores the importance of public-private partnerships and the need for transparent assumptions and communication in decision-making processes.

Key Information

• Hybrid LCOE: A weighted average of diesel and PV LCOE, plus system integration costs.
• Savings: Hybrid projects can save 12–16% when financed publicly, and 13–20% when financed privately.
• Impact of Diesel Price Volatility: LCOE is sensitive to diesel price changes, making long-term projections and risk mitigation essential.
• PV Penetration: Even with a 30–40% PV share, diesel remains the primary source of electricity due to evening demand peaks.
• Site Selection: Sites were chosen to represent a variety of conditions, including different isolation levels, customer types, and diesel prices.

Annexes

• Annex 1: Glossary of technical and financial terms.
• Annex 2: Technical fact sheets of the selected sites.
• Annex 3: Technical assumptions for system design and operation.
• Annex 4: Assumptions for demand growth and technical upgrades.

This study serves as a reference for future mini-grid development, encouraging stakeholders to explore hybridisation options and invest in detailed analyses to support sustainable and affordable energy access in remote areas.