Wind and solar energy can potentially be used to power desalination facilities to sustainably meet growing water demands with a smaller carbon footprint than conventional approaches. This work presents a detailed method for assessing the technical and economic viability of using these renewable forms of energy to power desalination facilities. The method relies on a multi-layered, spatial model that incorporated multiple variables such as depth of water resource, salinity levels, magnitude of local renewable energy resources, distance to water infrastructure, and, for comparative purposes, the local price of water. To illustrate this method, it was applied to 1445 site locations on state of Texas lands owned by the General Land Office that overlay brackish aquifer resources. Using this method, 193 potentially economically viable sites were identified that have estimated renewable desalination water production costs lower than local municipal water prices. The results of this analysis showed that using wind to power a desalination facility is economically preferable at 145 of the 193 sites; solar was preferable at the remaining 48 sites. Solar and wind resources are both abundant in Texas; however, the particularly high capacity factors for wind across much of the state helps wind deliver the lowest cost electricity.