GLOBAL ENERGY SYSTEMS NAVIGATOR:AN INTERACTIVE MAP OF ENERGY AND CARBON FLOWS

JEREMY HUDDLESTONLJUBA MILJKOVIC

WHAT GUIDES FLOW? APPROACH GEOLOGIC SAMPLE FUTURE WORKORIGINSMULTIPLE DATA ENCODING IN NETWORK VIEW

RESULTS

COLLABORATORS

The Global Energy Systems Navigator is an interactive map of the flows of carbon and exergy – the useful portion of energy – through global human energy systems.

It is an educational tool for anyone interested in better understanding the complex mechanisms by which we convert natural energy resources into end-uses.

The data were collected from dozens of reference sources such as International Energy Agency and UN databases, scientific journals, and government reports.

CARRIERS AND TRANSFORMATIONS

STATIC VISUALIZATION

INTERACTIVE VISUALIZATION

The data that make up the navigator are of two types:

• Carriers: mediums through which exergy and carbon flow

• Transformation: processes that convert one carrier into another

Crustal Thermal Energy

Solid EarthTides

Uranium Ore

Thorium Ore

Wind

Ocean Surface Waves

ShoreWaves

Coal

Natural Gas

Petroleum

Methane Clathrate

Methane

Liquid Methane

Plastics

Ethanol

Light Hydrocarbons

Metals

Processed Food

Construction Wood

Naphtha

Nuclear Waste

Steam

Chemicals

Organic Fiber

Organic Solid Waste

Visible Radiation

Hot Water

Warm Water

Air Kinetic Energy

Cool Air

Cold Air

Human Mechanical Work

Pipeline Mechanical Work

Tidal EnergyTransfer

AtmosphericAbsorption

WaterEvaporation

Surface Heatingand Cooling

Ocean SurfaceMomentum Transfer

Wind-LandFriction

Wind Fluid Friction

Surface WaveFriction

Liquid Fluid Friction

OceanTides

Natural Plant Decay

Volcanoes

HydrocarbonFormation

Tidal Friction

Conduction,Convection and Mixing

Crust-MantleHeat Transfer

CoalMining

Oil and GasExtraction

Electricity from Coal

Natural GasProcessing

Electricity fromMethane

Liquid FuelElectricity

MethaneLiquefaction

UraniumEnrichment

Electricity fromFission

PetroleumRefining

Paper ProductionBiodiesel Production

Ethanol Production

Metal Purification

Non-metallic Mineral Processing

Hydroelectricity

Geothermal Electricity

Tidal ElectricityElectricity from Solid Biofuel

Steam Production Steam Distribution

ChemicalProduction

Solid WasteConversion

Lighting

ElectricityDistribution

Air Cooling

IndoorAir Heating

Ventilation

Water Heating

Food Cooking

Manufacturing

Refrigeration

Electronics

Appliances

Road and Rail

Metabolism

Metal Oxidation

Light Absorption

PipelinesSeawaterUranium

Coal Products

Crude Oil

Metal ore

Air Mixing

10000 TW0.03 TW

Food Processing

FissileNuclides

Uranium 238

3.7

6000

900

150

150

60

3

110

160 ZJ

32

SeawaterDeuterium

3e7 YJ

360 YJ

0.234

2.31

0.03

1.0

0.30

0.19

0.70

0.32

0.11

0.14

0.021

0.007

0.011

0.016

0.29

0.13

0.8270 ZJ

50 ZJ

110 ZJ

10000 YJ

30 EJ

0.14

0.09

0.05

0.011

0.032

0.07

0.002 0.002

0.03

0.29

Aircraft0.330.2

5000

SurfaceReflection

Diffusion

Plants30 ZJ

100Ocean Thermal

Gradient

3.5

0.0003 Solar Electricity

Wind Energy Conversion

0.04Forestry

Agriculture0.014

Biodiesel0.057

Friction

Clouds

Plants

Photosynthesis

Precipitation360

4490

Hydroelectric Conversion

Coal Transformation

0.230 0.229

0.06

0.05 0.011

0.12

0.22

0.03 0.11

Charcoal Production0.110.032

0.95

0.73

0.04

0.27

0.0510.015

0.0013

0.0003

0.02

0.19

0.20

0.07 0.07

1.28

Methane Distribution

0.04

0.16

0.045

0.17 0.07

0.52

0.08

0.21

0.06

0.040.02

0.07

0.14

0.08

0.08

0.86

0.110.04

0.310.19

0.23

0.020

0.30 Shipping

0.57

0.11

0.022

Landfill0.9

0.313

0.01

0.14

0.02 Fertilizer

Unprocessed Food0.160.021

0.017

0.035

Fluid Friction

Fluid Friction

Fluid Friction

Fluid Friction

Friction

Friction

0.05

0.02

7 EJ

Pulp

Solar Radiation

Chemical Exergy

Nuclear Exergy

Gravitational Exergy

Thermal ExergyElectromagnetic Exergy

Flow

AccumulationFlow

0.09

25 ZJ

0.17

0.44

0.20

1.00

0.83 0.007

0.005

Geothermal Exergy

Kinetic and Work Exergy

Chemical Oxidation Thermal Mixing

Radiation Absorption FrictionDestructionKEY

Pumped Storage

0.004 0.003

0.002

Seawater Lithium

15000 YJ

300 ZJ

Fluid Mixing

0.344200 ZJ

Freshwater10

7

0.010

FissionableNuclides Nuclear Fuel

Reprocessing

Uranium238

Uranium Ore

27

11

17

91

16

0.8

21

88

Nuclear Waste

200 ZJ

0.050

0.061

0.33

0.03

0.12

0.059

0.09

0.05

0.09

0.053

1.15

0.001

0.011

0.98

0.02

ApplianceMechanical Work

0.12

0.23

VehiclePropulsive Work

0.09

0.095Aircraft Propulsive Work

Ship Propulsive Work

0.12

120000 62000

Extra-solarRadiation

15000

Electricity

Solid Biofuel

1.31 1.01

1.02

FlowKEY

0.05

0.01

0.01

1.66

0.29

23 EJ3

1

Upwelling

Natural Gas

Petroleum

Methane

LiquidMethane

Plastics

Ethanol

Light Hydrocarbons

Processed Food

Construction Wood

NaphthaChemicals

Organic Fiber

Organic Solid Waste

Volcanoes

HydrocarbonFormation

Electricity from Coal

Natural GasProcessing

Electricityfrom

Methane

Liquid FuelElectricity

MethaneLiquefaction

Human Appropriated Plants

Paper Production

EthanolProduction

Metal Purification

Non-metallicMineral

Processing

Electricity fromSolid Biofuel

Steam Production

ChemicalProduction

Solid WasteConversion

Lighting

IndoorAir Heating

Water Heating

FoodCooking

Manufacturing

Metabolism

Pipelines

Coal Products

Crude Oil

100 MgC/s

Food Processing

1000 PgC

50

5.4

3.1

12

5.4

3.3

3

0.5

1.7

Aircraft

Plants

Biodiesel1.4

CoalTrans-formation

2.2

4.1

0.4

0.2

CharcoalProduction

MethaneDistribution

1.0

2.00.4

1.8

21.5

1.6

Shipping

14

2.7

Landfill

Unprocessed Food4.0

0.2

Pulp

Plant CarbonRock Carbon

Ocean Carbon

Fossil CarbonFlow

Accumulation

Carbon Dioxide

5.3

2.3

Ocean Surface

Atmosphere-OceanDiffusion

Ocean SedimentConsolidation

950

Ocean SinkingTransport

AtmosphericCarbon Dioxide

810

Net AtmosphericAccumulation

Erosion

SubsurfaceCarbon Dioxide

5.0

8

17

8.0

8.7

1.7

8.6

3.30.1

1.3 0.5

9.1

16

1.3

9.3

0.5

0.9

0.9

18

5.3

28

14

6.3

5.5

1519

1.3

830

220

9.6

500

750

1

90

16

14

RockWeathering

56

36RiverOff-gasing

44

170

25

0.5

0.6

1.8 13

2.5

6.0

2.9

2.7 1.0

0.3

0.124

0.3

7.6

18

1.8

3.44.3

2.0

7.7

3.90.3

0.4

0.7

1.40.7 2.3

0.85.7

3.4

3.9

1.36.0

1.6

1.3

1.1

7.5

5.3

3.5

4.6

1.5

2.0

0.8

0.9

4

6

RockWeathering

6

River Transport76

Limestone

CoalMining

Anthropogenic Carbon Dioxide

5020

32

Paper

Charcoal

0.4

122

0.1

100 TW

1000 ZJ

Flow

Accumulation

1 TW

100 EJ

Flow

Accumulation

1.49

Paper0.07

0.06

Air Mixing

Air Mixing

Convection

Convection

FlowKEY

10 MgC/s

1 PgC

Flow

Accumulation

Photosynthesis

2250

Soils3000

Methane Clathrate3000

2300

8000Coal

37200Deep Ocean

Carbonate Rocks6.6e7

Solid Biofuel33

PetroleumRefining

42 Road and Rail

2.28

Prepared by Wes Hermann, Global Climate and Energy Project at Stanford University (http://gcep.stanford.edu), © 2007. Contact: gcep@stanford.edu

Exergy is the useful portion of energy that allows us to do work and perform energy services. While energy is conserved, its exergy content can be destroyed when the energy undergoes a conversion. We gather exergy from distinct, energy-carrying substances in the natural world we call resources. These resources are converted into forms of energy calledcarriers that are convenient to use in our factories, vehicles, and buildings. This diagram traces the flow of exergy through the biosphere and the human energy system, illustrating its accumulations, interconnections, conversions, and eventual natural or anthropogenic destruction. Choices among exergy resources and exergy carriers and the manner oftheir utilization have environmental consequences. An examination of the available resources and current human exergy use places the full range of energy options available to our growing world population and economy in context. This perspective may assist in efforts to both reduce exergy use and decouple it from environmental damage.

The ability of carbon-based molecules to store a large amount of useful energy, or exergy, has made carbon an important exergy carrier in natural and human energy systems. Carbon is being reintroduced to the biosphere through the human use of fossil fuels at a rate far exceeding its natural sequestration. This large and accelerating transfer of carbonto the atmosphere and upper ocean may lead to global environmental changes that would adversely impact our quality of life. This diagram traces the flow of carbon through the subsurface, the biosphere, and the human energy system. The energy conversions that lead to the sources of anthropogenic carbon dioxide are illustrated. In conjunction with theglobal exergy diagram above, alternate energy pathways that either do not require fossil carbon or store it in reservoirs other than the atmosphere and ocean surface can be examined in the context of current exergy use and carbon flow.

Human Body Heat

1 TW = 31.54 EJ/yr

1 MgC/s = 31.54 TgC/yr

Anthropogenic andNon-plant Fixed Carbon

270

Transport to Ocean 130

1000 ZJ

Lithium Ore3100 ZJ

30000 YJ

PlantRespirationand Decay

1980

500

Biodiesel Production

ContinentalPrecipitate

Transpirationand Evaporation27

Solar Radiation

56000

31000

41000

23000

Long Chain Liquid Fuel

Coal BedFires

3CoalBed

Fires

50

54

Oil and GasExtraction

100 10076

73 66

137

86

Agriculture90

49

Forestry63

41 Methane

Long Chain Liquid Fuel3.64

3.66

5.395.39

3.11

4.07

Methane2.74

2.22

1.95

Agriculture

HumanAppropriated

Plants

9.05.5

3.5 Forestry

200 EJMetal ore

Warm Air0.09

1.96

CookingGases

Air Mixing

69116

41

3.863.96

Long Chain Liquid Fuel

Long ChainLiquid Fuel

Sankey Diagram: developed at Stanford University

Strengths:

• Displays the entire system in a single view

• Complexity and interconnectedness of the system are apparent

• Relative magnitudes are perceptible

Weaknesses:

• Presentation must be very large to be legible

• Limited ability to “drill down” and explore the data

• Layout is arbitrary and drawn by hand

• No room for additional metadata

Design Goals:

• Dynamic, intelligent computer-generated layout

• Explore broadly and “drill down” for more information

• Limit the scope of data at any given time

• Presentable on the web on standard displays

• Relative magnitudes are perceptible

We have constructed an interactive web-based visualization that combines

a node-and-end view and quantitative stacked bar graph view.

NAVIGATION BAR

DETAILS VIEW

Presents all carriers and transformations in a searchable, filterable list.

• Mouse hovering over list items highlights the corresponding node and

its connections in the network view.

NETWORK VIEW

Presents the data broadly. Users can explore the data’s interconnectedness.

• Carriers and transformations appear as nodes, connected by edges.

• Carrier nodes are circles. Transformation nodes are small bar graphs

of the transformation’s exergy efficiency.

• Nodes are arranged so that primary resources appear to the left and

final end-uses appear to the right.

• Mouse hovering highlights node connections and displays a detailed

description of the chosen node.

METHODS

We achieve a good layout by basing the nodes' X positions on a weighted

average of its minimum and maximum depths in the network and the

depths of its neighbors.  The initial Y positions are random.

Next we start a physics simulation using three forces:

1. A spring force along edges that bring nodes close to their neighbors.

2. An repel force which reduces overlap of adjacent nodes.

3. A framing force which acts on nodes as they get close to the borders.

Presents quantitative view of an item with its inputs and outputs on either side.

• Hovering reveals that item’s value of exergy and carbon as well as a

detailed description of its role in the energy system.

• Clicking on an input or output item refocuses the view to center on it,

revealing its carbon and exergy inputs and outputs.

METHODS

• A stacked bar graph visualizes the proportion each input and output

contributes to the central item’s total exergy or carbon.

• Animation is used to refocus the view onto a new central item.

PATH HISTORY

BETTER INTEGRATION

Though the network view is designed to present the data broadly, we believe

more data could be encoded in the shapes, sizes, and even relative positions

of the nodes without causing distraction.

These data could be further explored by recording and comparing the

efficiency properties of various paths through the network. Users could, for

example, compare the carbon footprints of powering automobiles with

gasoline vs. electricity produced from solar power.

Smoother transitions between the network and details views are needed to

help users perceive them as part of a single interactive visualization.

Data for this project were collected at the Global Climate and Energy Project

at Stanford University.

NAVIGATION BAR

• Real-time search filters nodes to match the query.

• Buttons filter by item type (e.g. carrier, transformation) or

by position in the system (e.g. primary resource, end-use).

• Tool-tips display item’s carbon/exergy on mouse hover.

• Each time is tagged with the number of inputs and output.

DETAILS VIEW

• Central item’s exergy/carbon magnitude defines

the scale of the graph.

• Inputs and outputs are displayed as stacked on

either side in proportion to the central item.

• Clicking on an input/output refocuses the graph

and makes that item central.

• Carriers are blue. Transformations are orange.

• Tool-tips display the item’s carbon and exergy on

mouse hover.

NETWORK LAYOUT

LAYOUT BASED ON

WEIGHTED AVERAGE OF

MINIMUM AND MAXIMUM

DEPTHS IN THE NETWORK.

LAYOUT WITH SUPPLEMENTAL

PHYSICS SIMULATIONS.

Using a combination of weight averages of minimum and maximum node

depth and physics simulations, we achieve an effective layout of nodes.

REDUCED EDGE OVERLAP IN NETWORK LAYOUT

The network layout could be improved by applying algorithms to reduce edge

overlap and increase the proximity of connected nodes.

USER TESTING

As a tool intended for lay audiences, studies in usability would help determine

our designs address the needs of our target users.

DECEMBER 10, 2008. CS 264 - VISUALIZATION