description of the system boundaries and the level of technological detail of a model
[30]. The RES is the equivalent to the product system in LCA [20]. The level of
technological detail can be similar to process-based LCI databases. Thus, similar
descriptions of the energy supply chain—from resource extraction to final use—can
be found in both models. Linking ESM and LCI may seem straightforward, as both
models share a similar structure, but these models are conceived to be used independently, and overlapping features can easily result in problems such as double
counting [5, 6] or incomplete inventories. Faced with redundant information, the
modellers need to choose which information prevails. The methodological choices
may involve a trade-off between data quality aspects [19] which should be considered in the goal and scope definition.
Linking implies associating elements of the two models. We will refer to the
problem of associating elements of two different models as the “mapping problem”.
Several issues complicate the mapping problem. First, TIMES models often include
thousands of technologies, making a one-to-one linking between LCI and TIMES
processes almost infeasible. There are no general name conventions or standard
codes that can be used to automate the linking, which still heavily relies on manual
identification. Second, both models can track the same emissions (e.g. greenhouse
gases (GHG)), and some linkages between processes are not explicitly modelled in
TIMES (e.g. cement production and infrastructure development). Adding LCI in the
model can easily result in double counting [5]. Third, consistently introducing
life-cycle emissions in the optimisation problem often requires a one-to-one mapping of processes in TIMES and LCIs. For example, emissions from end-of-life
treatment could be included in TIMES, but these are potentially different for each
process. In most of the cases, a one-to-one mapping would be excessively
time-consuming. Fourth, key parameters of processes such as efficiency or emission
factors may differ between models, which can result in inconsistencies. Finally, if
multifunctional processes are within the system boundary, the allocation should be
avoided using system expansion [20]. However, this is hardly discussed in the
literature.
3 Existing Approaches to Address the Integration
Challenges
3.1 Mapping TIMES-LCA Processes
The “too many processes” issue preventing a one-to-one mapping is one of the most
complicated integration problems. This issue has been addressed using two simplifications: limiting the scope of the assessment to specific parts of the energy
supply chain and representing sections of the supply chain by their aggregated LCI
or LCA indicator.
Integrating Energy System Models in Life Cycle Management
253
[30]. The RES is the equivalent to the product system in LCA [20]. The level of
technological detail can be similar to process-based LCI databases. Thus, similar
descriptions of the energy supply chain—from resource extraction to final use—can
be found in both models. Linking ESM and LCI may seem straightforward, as both
models share a similar structure, but these models are conceived to be used independently, and overlapping features can easily result in problems such as double
counting [5, 6] or incomplete inventories. Faced with redundant information, the
modellers need to choose which information prevails. The methodological choices
may involve a trade-off between data quality aspects [19] which should be considered in the goal and scope definition.
Linking implies associating elements of the two models. We will refer to the
problem of associating elements of two different models as the “mapping problem”.
Several issues complicate the mapping problem. First, TIMES models often include
thousands of technologies, making a one-to-one linking between LCI and TIMES
processes almost infeasible. There are no general name conventions or standard
codes that can be used to automate the linking, which still heavily relies on manual
identification. Second, both models can track the same emissions (e.g. greenhouse
gases (GHG)), and some linkages between processes are not explicitly modelled in
TIMES (e.g. cement production and infrastructure development). Adding LCI in the
model can easily result in double counting [5]. Third, consistently introducing
life-cycle emissions in the optimisation problem often requires a one-to-one mapping of processes in TIMES and LCIs. For example, emissions from end-of-life
treatment could be included in TIMES, but these are potentially different for each
process. In most of the cases, a one-to-one mapping would be excessively
time-consuming. Fourth, key parameters of processes such as efficiency or emission
factors may differ between models, which can result in inconsistencies. Finally, if
multifunctional processes are within the system boundary, the allocation should be
avoided using system expansion [20]. However, this is hardly discussed in the
literature.
3 Existing Approaches to Address the Integration
Challenges
3.1 Mapping TIMES-LCA Processes
The “too many processes” issue preventing a one-to-one mapping is one of the most
complicated integration problems. This issue has been addressed using two simplifications: limiting the scope of the assessment to specific parts of the energy
supply chain and representing sections of the supply chain by their aggregated LCI
or LCA indicator.
Integrating Energy System Models in Life Cycle Management
253