 It is estimated that the development meets 60% of the power demand for the coastal region between the Golden Gate Bridge and the Oregon state line.Unlike most geothermal resources, the Geysers is a dry steam field which mainly produces superheated steam.Steam used at The Geysers is produced from a greywacke sandstone reservoir, capped by a heterogeneous mix of low permeability rocks and underlaid by a silicic intrusion.