Incorporating renewable energy in a desalination plant : case study in El Paso, Texas

El Paso is located in the westernmost part of Texas along the Rio Grande across from Ciudad Juarez, Mexico. Water supplies are a paramount concern for El Paso given its location in an arid climate. Although the Rio Grande runs past the city, prior appropriations for farming coupled with obligations to provide water to Mexico for agriculture limit the city’s use of the river in dry years. As a result, groundwater from the Hueco Bolson and Mesilla aquifers plays a pivotal role in El Paso’s water supplies. Both aquifers flow into Mexico and also primarily supply Ciudad Juarez’s water needs. The Hueco Bolson’s proximity to the Tularosa Basin, an enclosed prehistoric oceanic valley, causes the aquifer to have sizable supplies of freshwater and even larger amounts of brackish water. El Paso and Ciudad Juarez’s rapid population growth has led to accelerated drawdowns of the Hueco Bolson’s freshwater supplies, leaving both cities with increasingly brackish groundwater. In response to this problem, El Paso Water, El Paso’s water utility, constructed the Kay Bailey Hutchison Desalination Plant in a joint project with Fort Bliss. The plant uses reverse osmosis to desalinate brackish water and serves as a buffer against brackish water intrusion from the Tularosa Basin. Reverse osmosis is an expensive, energy-intense desalination process. El Paso’s sunny climate provides a perfect opportunity to reduce the plant’s long-term energy expenses through a solar-powered microgrid interconnected with the grid. Based on calculations from the HOMER model using the plant’s energy consumption data, a solar-powered microgrid could be a viable energy source that partially supplies the plant. The primary obstacles involve costs to build the microgrid and concerns from the grid administrator about potential damage to the grid. Therefore, it is important to look to the brisk decline in solar technology costs as well as to work with the grid administrator to increase the viability of such an endeavor. Given that desalination will play a greater role in El Paso’s water supplies and those of the world, scholars and policymakers from El Paso and Ciudad Juarez have an excellent opportunity to make this binational region a world leader in desalination with renewable energy.