For the InstructorThese student materials complement the Water Science and Society Instructor Materials. If you would like your students to have access to the student materials, we suggest you either point them at the Student Version which omits the framing pages with information designed for faculty (and this box). Or you can download these pages in several formats that you can include in your course website or local Learning Managment System. Learn more about using, modifying, and sharing InTeGrate teaching materials.
SWRO and Energy Costs
Technological advances, coupled with innovative approaches to reduce energy costs (i.e. by using solar, tidal, or ocean thermal energy) have helped to make SWRO a potential solution to water supply or hedge against climate change for large cities like Perth - rather than simply a novelty for wealthy countries. In the 1970s, SWRO costs hovered around $2.50/m3. Currently, costs for the most efficient plants are well below $1/m3, or between ~$1000-2000 per acre-foot (Figures 3 and 4). This is still more expensive than imported surface water or groundwater in most areas (these costs range from $400-1000/acre-foot, depending on location), but in the realm of viability for areas without those sources, or to augment limited supply. The total costs include everything from construction costs for the facility (amortized over its expected lifespan), land access, permitting for discharge and intakes, and operation & maintenance.
Despite its promise, it remains to be seen if SWRO will be a universal or large scale answer to water scarcity. In particular, key challenges include the (still relatively high) costs and associated energy demand; management of the environmental impact associated with intakes and disposal of the brine waste stream; delivery of SWRO water to regions away from the coast; and the up-scaling that would be necessary to meet demand for irrigation or industrial use.
1982: 1.55/m3 x 1m3/264 gallons = 0.0059/gallon x 1000 gallons = .90/1000gal. This is about 5 times the cost of typical water delivery in Las Vegas.
2010: 0.93/m3 x 1m3/264 gallons =0.0035/gallon x 1000 gallons = .50/1000gal. This is about 3 times the cost of typical water delivery.