Methodology of ecoinvent 3

Methodology of ecoinvent 3

How are electricity market mixes modelled?

Electricity market datasets are regularly updated and expanded to represent the latest available statistical data on present and projected future electricity mixes. The most recent update became available with v3.4. The applied methodology as well as difference compared to previous versions are explained here.

 

 

Cut-off & APOS System Model

In the attributional system models, electricity mixes in v3.4 (and 3.5) are based on statistical data of the year 2014 and are available for all 142 countries which are part of the IEA statistics (primary data source: IEA, 2016). That means, 100% of (statistically represented) global electricity generation is covered through country-specific market compositions.

 

Figure: Map of geographical coverage of electricity markets in ecoinvent version 3.4. The colors differentiate markets by the database versioning which they were added.

 

 

Consequential System Model

The consequential system model contains future electricity market compositions specific to 40 countries which together represent 76.5% of the global energy output.  These mixes are based on projections from (inter-)national authorities such as the European Commission (2016) and the international Energy Agency (2016). The new markets are a significant improvement of the consequential system model and provide a consistent basis for electricity supply in consequential LCA.

 

For countries where no specific scenario was available (marked orange in the map), the marginal electricity mix for the Rest of the World (RoW) applies. The RoW mix is calculated using the projections for the entire world from the “current policies” scenarios of the IEA (2016) minus the sum of all country specific projections.  Given the variety of the projection sources, there are some technologies which’s global electricity production according to the IEA is smaller than the sum of all the country specific scenarios for the same technologies. In these cases, the electricity production from these technologies is considered to be zero and is not part of the RoW marginal mix.

 

Imports are not taken into account in the composition of the consequential market mix because of the insufficient availability of consistent data. As this was already the case in previous versions, this does not subtract from the quality of the new data but it remains a limitation of the projection data.

 

Figure: Map of geographical coverage of consequential electricity markets in ecoinvent version 3.4. The colors differentiate markets with a specific (blue) or streamlined (orange) marginal electricity mix. Note that Chile has a specific marginal mix, despite it being colored orange.

 

 

How does the approach introduced with v3.4 differ from previous versions?

In versions 3.01  to 3.3 electricity mixes were generated by the linking algorithm, as described in the Data Quality Guidelines of ecoinvent version 3, section 4.3. The contribution of producing activities to the markets was calculated based on the production volumes specified in the electricity producing activities. From version 3.4 onwards, this rule does not apply. Instead, market mixes are generated by directly editing the contribution of the producing activities to the markets in the market activity itself.

 

The new approach may yield market shares that are not consistent with the production volumes specified in activities. Similarly, the Technology Level is not anymore deciding on which activities contribute to which market in the consequential system model.

 

 

Find out here how you can see the technology mix of an electricity market.

 

 

 

Reference(s):

International Energy Agency, (2016), World Energy Outlook 2016. Paris. https://doi.org/10.1787/weo-2016-en