For the analysis of economic impacts of the Bui Dam commissioning, PIO-CGE was calibrated using a disaggregated version of the 2015 SAM for Ghana \cite{ifpri2017} through the separation of electricity generation into hydro and non-hydro technologies. The costs structure used to conduct this disaggregation is reflective of the operation costs of hydro and non-hydropower technologies with cost information taken from the GTAP-Power database \cite{Peters_2016}. The resulting capital rents entering hydro-power cost structure were re-qualified as 'hydro capital rents' and were attached to the evolution hydro capital stock (dams).  Thus, the separation of power generation into these two categories allows for the construction of a 'without project' baseline in which the economic system adapts to a growing demand for electricity through investment in non-hydro capital (e.g. combustion power plants). 
Aggregation - sectors, factors and households
Since large-scale projects have impacts occurring over long time periods (50+ years), PIO-CGE is specified as dynamic-recursive model with labour supply supply and capital supply being updated to follow 18-65 population changes and investment-driven capital stock changes respectively.  In addition, for agricultural land, yields are assumed to increase over time with growth rates taken from the IMPACT model \cite{nelson2010food}.