【IRENA】终端用户部门的智能电气化：配电网的好处-2024

Summary of "Smart Electrification of End-Use Sectors: Benefits for Distribution Grids"

Core Content

This report by the International Renewable Energy Agency (IRENA) explores the benefits of smart electrification strategies for distribution grids, with a focus on Japan. It examines how integrating flexible distributed energy resources (DERs) such as electric vehicles (EVs), heat pumps, and rooftop photovoltaic (PV) systems can improve grid efficiency, reduce losses, and defer costly investments in grid infrastructure.

Main Points

1. Smart Electrification Overview

• Smart electrification involves the integration of flexibility from DERs to enhance the operation of distribution systems.
• This approach enables more efficient use of grid infrastructure, reduces energy losses, and lowers the marginal cost of electricity.
• It is essential for managing the increased variability and demand from renewable energy sources and electrified end-use sectors.

2. Benefits for Distribution Grids

• Grid Loss Reduction: Smart electrification can reduce grid losses by up to 3% of total energy delivered.
• Deferral of Grid Investments: By optimising energy use, the need for grid reinforcement can be delayed or even avoided.
• Economic Savings: For a grid serving 25,000 users, savings are estimated at USD 13.3 million (EUR 12 million) over a 40-year investment lifetime, equivalent to USD 8.3/MWh (EUR 7.5/MWh).
• Consumer Incentives: Financial incentives are crucial for encouraging consumers to react to grid signals and participate in demand-side management.

3. Key Flexibility Assets

• Electric Vehicles (EVs): Can be used for V1G (uni-directional) or V2G (bi-directional) smart charging, contributing to demand-side flexibility.
• Heat Pumps: Provide flexibility in heating and cooling, especially when equipped with thermal storage.
• Rooftop PV Systems: Generate on-site electricity, reducing grid dependency and improving local energy balance.

4. Importance of Smart Operation

• Smart operation of DERs allows for better load management and reduces peak demand.
• It is particularly important in regions with high electrification ambitions and inherent grid constraints, such as limited interconnections or renewable potential.

5. Japan as a Case Study

• Japan has a high grid utilisation rate due to its island-based energy system and high electricity demand density.
• The country is committed to carbon neutrality by 2050, driving significant electrification in sectors like transport and heating.
• Heat pump deployment is expected to grow from 0.3 GW (2023) to 1.7 GW by 2030 in the industrial sector, with similar increases in commercial and residential sectors.

6. Scenarios and Assumptions

• The BASE scenario includes a typical deployment of DERs without smart operation.
• The SMART scenario integrates all flexibility options, leading to the best results in terms of grid efficiency and cost savings.
• The study assumes a linear growth of EVs and heat pumps from 2023 to 2050 and uses a CIGRE medium-voltage network as the base for analysis.

Key Findings

• Flexibility from DERs is critical for managing the variability of renewable energy and reducing grid congestion.
• Climate conditions influence the choice of flexibility options: in mild climates, V1G is sufficient, while in cold climates, V2G and thermal storage are more effective.
• Smart electrification can reduce the level-of-use ratio of critical grid lines by 50%, significantly lowering the need for grid reinforcement.
• End users with flexible assets (e.g., EVs, heat pumps, PV) can play a key role in demand-side management.
• Commercial and industrial users may be more responsive to demand-side management than residential users.

Economic and Operational Benefits

• Unitary energy costs can be reduced from USD 77.2/MWh (EUR 69.4/MWh) in the BASE scenario to USD 67.6/MWh (EUR 59.9/MWh) in the SMART scenario.
• This equates to annual savings of USD 2.9 million (EUR 2.6 million), or more than USD 222 (EUR 200) per household.
• Load duration curves and voltage profiles show improved grid stability and efficiency under smart electrification.

Scope and Limitations

• The study focuses on a residential distribution grid and does not include commercial or tertiary demand profiles.
• It assumes that flexibility assets are already deployed and available.
• Other grid-related aspects such as dynamic stability, short-circuit calculations, and reverse power are not considered in this analysis.
• The model is based on intermediate latitude conditions, similar to Japan, with cold winters and mild summers.

Conclusion

Smart electrification strategies, particularly those that harness flexibility from DERs, are essential for future-proofing distribution grids and reducing the need for costly infrastructure upgrades. These strategies not only improve grid efficiency and reliability but also offer substantial economic benefits through reduced energy losses and deferred investments. The case of Japan demonstrates the potential of smart electrification in high-demand, high-electrification environments, highlighting the importance of policy support, financial incentives, and technological integration for achieving sustainable energy transitions.