Development of Foundation Systems for Solar Array at Owens Lake, California

Abstract

Owens Lake, located in Central California, has been a dry lakebed for almost a century, ever since the water rights in the Owens Valley were purchased by the City of Los Angeles and the water was diverted to the City. As a result of the diversion, the salt-laden lakebed sediments are picked up by the wind, creating major dust storms. Various dust mitigation projects have been implemented over the years. The most common method is the creation of shallow ponds. This method is effective but costly and highly water intensive. A large solar panel array has been proposed as a more sustainable method of dust control which would reduce water usage at the lake and also be a source of electrical power. However, the lake bed sediments are very poor soils, not generally considered viable for solar panel foundations. The poor quality of the soils made both tradition site investigation methods and traditional empirically based design methods inappropriate. This paper describes an innovative testing system which was developed to allow for efficient field load testing of the foundation systems being considered. This project provides an example of how sustainability concerns have actually led to exploring viable foundation designs for a site previously considered to be unsuitable.