Evaluation of Solar Technology in a Biosolids Drying Application

The San Francisco Public Utilities Commission (SFPUC) decided to evaluate whether advances in solar heating technologies are such that a compact solar dryer could be feasibly installed for biosolids drying at one of the City of San Francisco's two urban treatment plants. An experimental chamber was constructed to test the solar drying concept. Temperature inside and outside of the chamber was measured using an Onset HOBO™ data logger, capable of taking and recording periodic temperature measurements. Results of experiments conducted with biosolids indicate that this technology could be promising for an urban drying application.