Energy Flow Sankey Diagram: Editable Template
An editable energy flow Sankey for a site: fuels and electricity in, conversion losses, and end uses out. Illustrative figures you replace with your own metered data.
An energy flow Sankey follows energy from its sources, through the equipment that converts it, to the uses it ends up serving. The losses along the way are ribbons too, which is the point: they are normally the part nobody sees.
The template models a single site with three inputs: natural gas, grid electricity and rooftop solar. Gas feeds a boiler and a combined heat and power unit; both produce heat, the CHP also produces electricity, and each conversion loses some energy. Heat and electricity then split into end uses.
The numbers are invented for the example, in GWh, and are balanced so that the energy in equals the energy delivered plus the losses. They are not data about any real site and not a substitute for an energy audit or for reporting under any standard. Replace them with your own metered values.
How to read this diagram
- Total input is 900 GWh: 500 gas, 350 grid electricity and 50 solar.
- Of the 500 GWh of gas, 65 GWh is lost in conversion (45 in the boiler, 20 in the CHP); the rest becomes heat or electricity.
- Electricity (470) is the larger carrier, and most of it goes to motors and drives.
- Electricity from the CHP, the grid and solar merge into one carrier, so the diagram shows what is consumed rather than which source supplied which use.
The data behind it
Invented figures in GWh for one year at one site. They are not measurements and not sourced from any real facility.
| From | To | Amount (GWh) |
|---|---|---|
| Natural gas | Boiler | 300 |
| Natural gas | CHP unit | 200 |
| Boiler | Heat | 255 |
| Boiler | Conversion losses | 45 |
| CHP unit | Heat | 110 |
| CHP unit | Electricity | 70 |
| CHP unit | Conversion losses | 20 |
| Grid electricity | Electricity | 350 |
| Rooftop solar | Electricity | 50 |
| Heat | Space heating | 240 |
| Heat | Process heat | 125 |
| Electricity | Lighting | 90 |
| Electricity | Motors and drives | 230 |
| Electricity | Cooling | 110 |
| Electricity | IT | 40 |
The same data as CSV
source,target,value
Natural gas,Boiler,300
Natural gas,CHP unit,200
Boiler,Heat,255
Boiler,Conversion losses,45
CHP unit,Heat,110
CHP unit,Electricity,70
CHP unit,Conversion losses,20
Grid electricity,Electricity,350
Rooftop solar,Electricity,50
Heat,Space heating,240
Heat,Process heat,125
Electricity,Lighting,90
Electricity,Motors and drives,230
Electricity,Cooling,110
Electricity,IT,40How it works
List the sources and end uses
Add the energy inputs on the left and the uses on the right. Use the same unit for everything, such as kWh or GWh.
Add the conversion steps
Add boilers, turbines, transformers or any equipment that converts one form of energy into another. Give each one a flow to its output and a flow to a losses node.
Check the balance
Energy in should equal energy out plus losses at every node. QueryChart marks a node that sends out more than it receives.
Frequently asked questions
Does this show real energy data?
No. The figures are invented to demonstrate the structure. Use your own metered or audited values.
Is a Sankey diagram an energy audit?
No. It is a way of presenting energy data you already have. It does not measure or verify anything, and it does not satisfy reporting or compliance requirements on its own.
How do I show losses?
Give each converting node a flow to a Losses node. The loss is whatever the node receives and does not pass on.
Edit this energy Sankey
Open the template as your own chart and replace the sources, equipment and uses with yours.