Lookup

The document describes the Lookup function, which calculates a dependent value based on an independent branch:variable reference using either a 'Linear' method for interpolation or a 'Step' method for discrete changes. It specifies that independent value parameters must be listed in ascending order and provides a practical example of calculating the decreasing unit capital cost of wind power relative to installed capacity.

• The Lookup function supports two calculation methods: the Linear method, which performs linear interpolation between table values, and the Step method, which handles discrete, step-wise changes.
• When using the Lookup function, the independent value parameters (IV) must be entered in ascending order of value.
• The function can be applied to model energy transition costs, such as wind power capital costs decreasing from 200 $/kW to 100 $/kW as installed capacity increases from 1000 MW to 10000 MW.

APA

Stockholm Environment Institute (n.d.). Lookup. https://leap.sei.org/help24/Expressions/Lookup.htm?agt=index

Chicago

Stockholm Environment Institute. Lookup. n.d. https://leap.sei.org/help24/Expressions/Lookup.htm?agt=index.

Wikipedia

{{cite report |author=Stockholm Environment Institute |title=Lookup |url=https://leap.sei.org/help24/Expressions/Lookup.htm?agt=index |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{stockholmenvironmentinstitutendlookup, author = {{Stockholm Environment Institute}}, title = {{Lookup}}, institution = {Stockholm Environment Institute}, url = {https://leap.sei.org/help24/Expressions/Lookup.htm?agt=index}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }