More joules per drop – how much water does unconventional gas use compared to other energy sources and what are the legal implications?

Water is critical to energy security. This article compares “joules per drop”, or the equivalent joules of energy per litre of water for selected energy sources that include unconventional gas and renewables. The volumes of co-produced water during coal seam gas operations for example vary by a factor of at least 100 between different geological basins. Yet, typical unconventional gas has a much higher “joules per drop” (up to 909 MJ/L) than that of solar thermal and biomass energy (only 8 and 0.02 MJ/L respectively). Optimizing the future portfolio of energy sources should include a goal of reducing the lifecycle of freshwater use. Potential law and policy applications arise throughout the different stages of an energy production project: from strategic decisions about a desirable energy mix, to assessments for granting environmental approvals and water entitlements, to providing information to consumers about the sustainability of their energy source.