Integration of hydropower in the IMAGE/TIMER model - Steps toward endogenous modelling of global hydropower by construction of regional cost supply curves

Abstract

In the electricity sector, hydropower or “hydro-electricity” is currently the largest renewable energy source, with a global capacity of about 1 TW in 2013 and providing 85% of global electricity from renewable sources. However, despite the importance of the resource many energy models pay much less attention to hydropower than to other renewables. In the energy model TIMER used at PBL Netherlands Environmental Assessment Agency as part of the IMAGE framework, hydropower is modelled as an energy technology that has a prescribed capacity and does not compete on a cost base with other energy technologies to gain market share. This is done by calculating a desired fraction of the ultimate exploitable hydropower potential. The current representation in TIMER of hydropower, however, has severe limitations. Renewable energy is becoming increasingly important, given the expected increase in overall energy demand, the depletion of conventional fossil resources and climate change. Hydropower could therefore become more attractive than historically.

This work contributes to a renewed representation of hydropower in TIMER by means of regional cost supply curves. The costs supply curves are determined in a sequence of process steps. First, the theoretical potential for hydropower is calculation using discharge data from hydrological models and elevation data from DEMs. Next, geographical constraints and technical limits are added. After this, the LCOE of hydropower is calculated. Finally, the technical potential per region and LCOE are aggregated into cost supply curves.

The cost supply curves seem reasonable at representing large regions since lots of hydropower production points lay on realistic positions on the costs supply curves. Some regional technical potentials are overestimated and some underestimated compared to survey data. The reasons for this are different per region. Some correction factors were introduced to improve the representation of smaller IMAGE regions such as Japan, Central America and Europe.