可再生能源的电网整合技术简介（英文版）_36页

Renewable Energy Integration in Power Grids Summary

Core Content

This document provides an overview of the challenges and opportunities associated with integrating renewable energy (RE), particularly variable renewable energy (VRE) such as wind and solar power, into existing power grids. It outlines the technological, economic, and policy considerations required to support a transition towards higher renewable shares in the electricity mix.

Main Viewpoints

• Renewables are increasing rapidly in power generation, with over half of all new capacity added since 2011 being renewable.
• VRE technologies (wind, solar) are non-dispatchable and depend on weather conditions, which introduces variability and uncertainty into the grid.
• The integration of VRE requires grid flexibility, which can be achieved through smart grid technologies, energy storage, flexible generation, and grid interconnection.
• Policy and regulatory frameworks are essential to support the transition, including the creation of new markets for ancillary services and incentives for VRE integration.

Key Information

Renewable Energy Categories

• Dispatchable renewables: Hydro, geothermal, biomass — can be controlled to meet demand.
• Non-dispatchable renewables (VRE): Wind, solar PV, concentrating solar power, ocean power — depend on natural conditions.

Integration Challenges

1. Variability and uncertainty: Fluctuations in generation output due to weather and time of day.
2. Location-specific properties: Renewable resources are not evenly distributed geographically.
3. Low marginal costs: Resources are freely available, which reduces generation costs but increases system integration costs.
4. Impact on grid stability: VRE can cause voltage fluctuations and affect protection systems.

Integration Requirements

• Bi-directional energy flow: Allow both generation and consumption to interact with the grid.
• Demand-side management: Use technologies like Demand Side Management (DSM) and Advanced Metering Infrastructure (AMI) to manage load.
• Grid interconnection: Improve regional and international interconnections to increase balancing capabilities and stability.
• Energy storage: Use technologies like pumped-storage hydro, batteries, and hydrogen storage to manage short and long-term variability.

Smart Grid Technologies

• Smart grids enhance grid reliability, efficiency, and flexibility.
• They incorporate information and communication technologies (ICT) to enable real-time monitoring and control.
• Advanced inverters are crucial for VRE integration, especially at higher penetration levels, providing functions such as frequency and voltage control, fault ride-through, and reactive power support.
• Smart grids can automate grid operations and shift demand to off-peak times through intelligent appliance management.

Integration Costs

• Grid infrastructure costs include connection and upgrading costs, estimated at up to 5% of project investment for most renewables and up to 14% for onshore wind.
• System operation costs are significant, especially at higher VRE penetration rates (30%–40%), where profile costs (due to reduced plant utilization) account for more than half of the total integration costs.
• Balancing costs increase with the share of VRE, requiring more reserve capacity and operational interventions.

Policy and Market Considerations

• Policy makers need to develop long-term frameworks that support RE development and manage variability.
• Regulatory environments must provide stability and incentives for grid upgrades and VRE integration.
• Market design should include new revenue streams and price signals for VRE generators and ancillary services.

Technology Options for Integration

• Smart grid technologies: Enable flexible and reliable grid operation, reduce peak loads, and support VRE integration.
• Energy storage: Includes pumped-storage hydro, batteries, hydrogen, and thermal storage to manage short and long-term variability.
• Flexible generation: Adjust the energy mix to better accommodate VRE.
• Grid extension: Improve interconnection to enhance balancing capabilities.
• System-friendly VRE: Technologies that can provide ancillary services and operate more predictably.

Potential and Barriers

• Potential: High renewable shares are achievable with the right technological and regulatory support. Small islands and European countries have shown successful integration experiences.
• Barriers: Include technical challenges such as voltage fluctuations, fault ride-through (FRT) requirements, and impacts on protection systems. Economic and regulatory frameworks are also critical for the transition.

Conclusion

The integration of renewable energy, especially VRE, into power grids requires a comprehensive approach involving technological innovation, economic analysis, and policy reform. Smart grid technologies and energy storage are key enablers, while the development of appropriate regulatory frameworks is essential to support long-term sustainability and system flexibility.