20110228-IEA-Integration_of_Renewables_34页_1mb

Summary of "Integration of Renewables: Status and Challenges in China" (IEA, 2011)

Core Content

This working paper by the International Energy Agency (IEA) explores the status and challenges of integrating renewable energy, particularly wind power, into China's electricity system. It highlights the country's rapid growth in renewable energy capacity, the structural limitations of its current grid system, and the need for flexible generation and storage solutions to manage the variability of renewable sources.

Main Views and Key Information

1. China's Energy and Electricity Context

• China is a country with a vast land area (9.6 million km²) and a large population (14% of the world's population).
• Electricity supply security is a key concern, especially due to extreme weather events and the reliance on coal as the primary energy source.
• China's electricity demand is projected to almost triple by 2035, reaching 9,594 TWh, with an average growth rate of 5.3%.

2. Renewable Energy Development

• Coal remains the dominant source of electricity generation, accounting for ~80% in 2009.
• Wind energy has grown rapidly, increasing more than tenfold from 28 MW in 1996 to 42 GW by 2010.
• In 2010, China surpassed the United States to become the world's largest wind power capacity holder.
• The National Energy Administration (NEA) has set ambitious targets for 2020: 150 GW wind, 20 GW solar, 380 GW hydro, and 80 GW nuclear.

3. Challenges of Renewable Integration

• Variable Renewables: Wind and solar are intermittent and unpredictable, requiring flexible and responsive power systems.
• Geographic Mismatch: Wind farms are concentrated in the north and northeast, far from main demand centers in the east.
• Grid Constraints: Limited inter-regional grid connections and insufficient transmission infrastructure hinder the efficient transmission of surplus renewable energy.
• Curtailment: Wind farms often face curtailment, especially during periods of high demand or low demand, due to grid limitations.

4. Regional Electricity Transmission

• China's grid is divided into six regional clusters, each operating independently.
• The State Grid Corporation of China (SGCC) manages four clusters, while the South grid is managed by the China Southern Grid Company (CSGC).
• Inter-regional electricity trade is limited to 4% of total production, but is expected to grow.
• SGCC is expanding ultra-high-voltage (UHV) transmission networks to enhance long-distance electricity delivery.
• UHV lines are more efficient than traditional 500-kV lines, reducing power losses and enabling large-scale renewable integration.

5. Flexible Generation and Storage

• Ancillary Reserves: A range of reserves (primary, secondary, tertiary) is necessary to manage supply fluctuations and maintain grid stability.
• Coal-Fired Plants: While they are flexible for short-term load changes, they are less efficient and more costly when not operating at full capacity.
• Small Coal Plants: These are being phased out to improve efficiency and reduce emissions, reducing the number of flexible dispatchable resources.
• Natural Gas Plants: Currently account for less than 1% of electricity generation, but are considered a flexible resource for balancing variable renewables.
• Hydro Power: Contributes significantly to non-fossil energy and offers flexible generation, but is also subject to seasonal variability.

6. Demand-Side Management and Storage

• Demand-side management is being promoted to better align supply and demand.
• Electricity storage is still limited in China, but is seen as a key solution to manage variability and improve grid flexibility.
• Smart grid initiatives, including demand response and advanced grid control, are being developed to enhance the integration of renewables.

7. Policies and Standards

• The Renewable Energy Law (2005) has played a crucial role in promoting renewable energy growth.
• The Chinese government is working on updating policies and setting technical standards to support renewable integration.
• These efforts include targeted policy making, improving market mechanisms, and enhancing grid infrastructure.

Conclusion

China's integration of renewable energy, particularly wind, is progressing rapidly, but faces significant challenges due to geographic mismatch, grid limitations, and the dominance of coal in the energy mix. The country is investing in long-distance transmission infrastructure and promoting flexible generation and storage solutions to address these issues. A national smart grid system is being developed to improve coordination and efficiency, which is expected to be a key enabler for higher renewable penetration in the future. The success of these efforts will depend on continued policy support, technological innovation, and market reforms to ensure reliable, affordable, and clean electricity supply.