Energy Sankey

Sankey diagrams are a visual representation of the information available in an energy balance. They allow to “follow the flow” of each energy commodities from supply on the left part to the final consumption and exit from the national supply on the right.

The first nodes you can find on the left side represent the domestic production of primary energy commodities and imports of energy commodities. Then a second set of nodes will include in addition of this supply the primary energy equivalent for renewable and nuclear electricity and heat generation. Please refer to the Energy Statistics Manual for more information.

In the block of Transformation nodes, you can see the inputs on the left and outputs on the rights of power and heat generation, refineries and other transformation. Clicking on the nodes allows you to visually see the efficiency of those transformation by comparing the size of the input flows and output.

Following the transformation nodes, you can find to their right the national supply of secondary energy commodities. You can notice that by clicking on the primary or secondary supply nodes you can see the statistical differences on the left or the right of the node, depending on the sign of this difference.

On the bottom right you can see other flows representing “exits” of the energy commodities from the national supply: the inputs to international bunkers, the transmission and distribution losses and the exports. The presence of those flows to the right of the graph is the reason why you can’t see a Total Energy Supply in this graph.

The last block represents the final consumption of energy commodities in the country.

In the energy balances from which the Sankey diagrams are derived, inputs to transformation processes are expressed as negative values, and outputs are expressed as positive values. For energy commodity categories that include both primary and secondary energy commodities, namely “Coal and coal products” and “Biofuels and waste”, this methodology can result in the inputs and outputs of a transformation process cancelling each other out, leaving only the transformation losses. In the Sankey diagrams, this situation is visualized as flows on the left of a transformation node without any flows on the right. Common occurrences of this case and other details about transformation nodes in the Sankey diagrams are described below. Minor inputs and/or outputs of transformation processes may be omitted from the Sankey diagram to improve readability.

Power and heat plants: Includes transformation in electricity, CHP, and heat plants, as well as heat pumps, electric boilers, and chemical heat for electricity production.

Coal transformation: Includes transformation in blast furnaces, coke ovens, patent fuel plants, and BKB/peat briquette plants. Natural gas, oil products, and biofuels and waste may exceptionally be used as supplementary inputs to coal transformation processes.

Refineries: Transformation of hydrocarbons for the production of finished oil products.

Gas works: Includes transformation in gas works and blending with natural gas.

Liquefaction plants: Includes transformation in coal liquefaction and gas-to-liquids (GTL) plants.

Other transformation: Includes transformation in petrochemical plants, charcoal production plants, and non-specified transformation processes. Charcoal production from primary solid biofuels results in transformation losses of biofuels and waste in the Sankey diagram. Primary oil output from this node often represents refinery feedstocks transformed from oil products in petrochemical plants or hydrogen manufactured from natural gas.