The Energy-Water Nexus
Bringing Together Different Perspectives
Water
• Climate change is a key
driver of water systems.
• Current focus is water
sufficiency and climate
change adaptation.
• Energy dimension
provides new insights into
mitigation potential in the
water sector.
Energy
• Energy systems drive
climate change
• Current focus is energy
sufficiency and climate
change mitigation.
• Water dimension provides
new insights into how
climate adaptation will
affect energy systems.
Charles Heaps, Ph.D. Director, US Center of SEI
1
charlie.heaps@sei-us.org
A Few Nexus Issues
• Hydropower
• Cooling Water for Thermal
Power Systems
• Energy for Desalination
• Water and Land-use for
Biofuels
• Energy for Agricultural
Pumping
• Energy and Water for
Sewage Systems
• Integrating Mitigation and
Adaptation
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Models to Support Nexus Policy
• Rather than create new tools unfamiliar to both energy and water
professionals, link existing tools that are already widely used and credible
in both fields.
• Provide insights to both groups as a way of starting dialogue between
energy and water professionals.
• Over last two years, SEI has been developing such a system based on its
existing modeling tools: LEAP (energy) and WEAP (water).
• Tightly coupled system where LEAP and WEAP run together and are
dynamically linked: each tool can request data or results from the other.
• Common assumptions on scenarios, seasonal/time of day information,
geographic boundaries
• Flexible enough to model a wide variety of energy-water issues.
• Transparent & easy to use for a wide target audience, but powerful
enough to provide genuine insights.
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Long range Energy Alternatives Planning System
www.energycommunity.org

Integrated energy planning and GHG mitigation assessment.

Local, national, regional and global applicability.

Energy, emissions and cost-benefit assessment.

Fast, transparent, powerful data management, reporting &
scenario building tools.

Choice of methods: simulation/optimization &
engineering/econometrics.

Widely applied (1000s of users in 195 countries).

Used by governments, NGOs, utilities, universities, consulting
companies.

Recent applications:

2012: Energy for All: 20 region global energy study for Rio+20

2010: Modeling to support the Massachusetts Clean Energy & Climate Plan

2009: Europe’s Share of the Climate Challenge
Water Evaluation And Planning System
www.weap21.org
• Integrated watershed hydrology and water planning
model
• GIS-based, graphical drag & drop interface
• Physical simulation of water demands and supplies
• Additional simulation modeling: user-created
variables, modeling equations and links to
spreadsheets, scripts & other models
• Scenario management capabilities
• Groundwater, water quality, reservoir, hydropower and
financial modules
6
Results Displayed on the Map
7
Linking Water and Energy Issues
Groundwater depletion
Water quality
Unmet ecological flows
Costs
Insufficient water for hydro and
cooling, even with increased
groundwater pumping.
Still insufficient water--further
enhance supply with
desalination.
Limited hydropower & cooling
water, increased energy
requirements for pumping.
Increased energy requirements
for desalination.
Electricity demand
Energy efficiency
Water
Supply
Water
Demand
Energy
Demand
Energy
Supply
Water requirements for
hydropower & thermal cooling
Hydropower & fossil
generation
Wind & solar, less waterintensive cooling
Water conservation
Hydropower energy &
cooling water requirements
Reduced water demands
Fuel Use
GHGs
Local air pollution
Costs
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Status
www.weap21.org
www.energycommunity.org
Beta version being tested: full release summer 2012
Charles Heaps, Ph.D. Director, US Center of SEI
9
charlie.heaps@sei-us.org