2016世界能源展望_水和能源关系（英文版）_61页_2mb

Water Energy Nexus Summary

Core Content

The Water Energy Nexus highlights the critical interdependencies between water and energy systems, emphasizing that both resources are essential for economic and social development. Water is required at every stage of energy production, from fossil fuels to biofuels, while energy is crucial for water supply, treatment, and distribution. These linkages have significant implications for energy and water security, especially as both demands are expected to rise in the coming decades.

Main Points

• Interdependencies: Energy and water are mutually dependent. Water affects the viability of energy projects, and energy is vital for water services.
• Energy for Water: The water sector consumes a significant amount of energy, with its demand set to more than double by 2040. In 2014, the energy used in the water sector was equivalent to the entire energy demand of Australia, with most of it in the form of electricity.
• Water for Energy: The energy sector accounts for about 10% of global water withdrawals, primarily for power plant operations and fossil fuel production. By 2040, water withdrawals for energy production are expected to rise by less than 2%, but water consumption will increase by almost 60%.
• Scenarios: The report presents two main scenarios:
  • New Policies Scenario: Reflects current and announced policies, projecting a modest increase in water withdrawals and a significant rise in water consumption.
  • 450 Scenario: A decarbonisation pathway aiming to limit global temperature rise to 2°C, which results in lower water withdrawals but higher consumption due to increased use of water-intensive technologies like biofuels, nuclear, and concentrating solar power.
• Water Stress: Over a billion people currently live in areas of water stress, and this number is expected to triple by 2025. Water stress is defined by the availability of renewable water resources per person.

Key Information

• Energy Consumption in Water Sector: In 2014, the water sector used 120 Mtoe of energy, with 4% of global electricity consumption dedicated to water extraction, treatment, and distribution.
• Water Treatment and Desalination: These processes account for a large share of the water sector's energy use, with desalination being a major contributor.
• Desalination Growth: By 2040, desalination is projected to account for 4% of water supply and 60% of the water sector's energy consumption, particularly in the Middle East.
• Energy Efficiency Potential: There is significant potential for energy savings in the water sector, with a 15% reduction in energy use possible by 2040 through improved efficiency and energy recovery.
• Integrated Approach: The report underscores the importance of integrated thinking and policies to manage the energy-water nexus effectively, reducing unintended consequences and enhancing sustainability.

Future Projections

• Water Withdrawals: Expected to increase by almost 10% from 2014 to 2040, with the largest increase in municipal water demand.
• Water Consumption: Projected to rise by over 20% over the same period, driven by agricultural and industrial use.
• Desalination: Expected to grow over eight-fold by 2040, significantly increasing the water sector's energy demand.

Challenges and Opportunities

• Trade-offs: Decarbonisation pathways can increase water consumption, requiring careful management to avoid exacerbating water stress.
• Energy Recovery: Harnessing the energy embedded in wastewater could provide over 55% of the electricity needed for municipal wastewater treatment by 2040.
• Water Loss Reduction: Reducing water losses could save energy equivalent to the entire electricity needs of Poland today.
• Collaboration: Successful mitigation of future stresses requires collaboration between policymakers, researchers, industry, and consumers.

Conclusion

The Water Energy Nexus is a complex and critical issue with far-reaching implications for both sectors. Understanding and managing these linkages is essential for achieving sustainable development and climate goals. The report provides a foundation for informed policy-making and technological innovation to address the challenges and opportunities presented by the nexus.