The water footprint of electricity in Ecuador: Technology and fuel variation indicate pathways towards water-efficient electricity mixes

Abstract

Hydropower, biomass and thermal power plants (HPPs, BPPs and TPPs) consume water. The WF tool quantifies freshwater consumption. We calculated direct and indirect WFs of 255 Ecuadorian power plants using different technologies and fuels classified into eleven subclasses. Median WFs are largest for BPPs, followed by HPPs, while WFs of TPPs were smallest, but variation in subclasses is enormous. For HPPs, dammed HPPs have relatively large blue WFs, run-of-the-river HPPs have relatively small WFs, although they are significant to their electricity output. The cooling system is paramount for TPPs subclasses. Water-efficient cooling systems (once-through and dry-cooling) have 20% smaller WFs than wet-tower systems. Moreover, the fuel used affects the direct WF of TPPs significantly. Fuel and residue oil require water-intensive preheating; some diesel-fired TPPs use water as GHG control. BPPs are water-intensive because biomass has a large WF. Technology and fuel variation indicate pathways towards more water-efficient electricity mixes.