Panel designed as part of its Joint Development Agreement (JDA) with REC and exclusive to SunPower. Monolith II set the latest SunPower panel power record since its 333-watt record in 2009. Monolith II maximizes total kilowatt hours (KWh) per year, literally the actual "payback" of solar systems.

SunPower successfully commercialized Monolith, a 470-watt panel developed by the SunPower-REC JDA. The Monolith panel uses REC’s advanced N-Type Heterojunction (HJT) cell technology, which provides superior power output and annual energy production, exceptional aesthetics and a solid 25-year warrantee. Monolith II panels produce 522 watts from the first Monolith footprint and weight by encapsulating REC’s N-Type HJT wafer technology in a "bifacial" panel with glass on both the front and back sides to illuminate the cells from both sides.