Development of life cycle water footprints for gas-fired power generation technologies

• Water consumption and withdrawals coefficients for gas-fired power generation.
• Life cycle water footprints for 18 gas-fired electricity generation pathways.
• Different gas-fired power generation technologies were assessed.
• Sensitivity analysis on water demand for upstream and power generation stages.

The key objective of this paper is to develop a benchmark for water demand coefficients of the complete life cycle of natural gas-fired power generation. Water demand coefficients include water consumption and water withdrawals for various stages of natural gas production as well as for power generation from it. Pathways were structured based on the unit operations of the types of natural gas sources, power generation technologies, and cooling systems. Eighteen generic pathways were developed to comparatively study the impacts of different unit operations on water demand. The lowest life cycle water consumption coefficient of 0.12 L/kW h is for the pathway of conventional gas with combined cycle technology, and dry cooling. The highest life cycle consumption coefficient of 2.57 L/kW h is for a pathway of shale gas utilization through steam cycle technology and cooling tower systems. The water consumption coefficient for the complete life cycle of cogeneration technology is in the range 0.07–0.39 L/kW h and for withdrawals ranged 0.10–14.73 L/kW h.