PTAB Reiterates Strict Evidentiary Standard For Printed Publications

The PTAB denied institution of inter partes review (IPR) for a patent directed to geothermal technology. Fervo Energy Co. v. Ormat Techs. Inc., IPR2014-00665, Paper 18 (PTAB Sept. 18, 2024). The claimed invention related to "enhancing the flow of geothermal fluid" via horizontal wells which "generate a water density difference and a pressure difference." Petitioner challenged all claims under 35 U.S.C. § 103. Because the record did not include publication dates for two references, the PTAB determined neither reference was available as prior art. This decision reinforces the strict evidentiary standard required to establish a printed publication as prior art in IPR proceedings.

For a printed publication to qualify as prior art in an IPR, a reference must be publicly available. The Federal Circuit recently described "publicly available" as "whether interested members of the relevant public could locate the reference by reasonable diligence." Weber Inc. v.