The successful operation of the direct steam generation could be verified under real solar conditions in a test facility at the Plataforma Solar de Almería (PSA), owned by the Spanish cooperation partner CIEMAT. The DISS test facility (derived from Direct Solar Steam) comprises one collector loop with a length of 1000 meters and can generate steam at up to 110 bars and 500°C. The test facility already corresponds to a commercial size, and, therefore, tests do usually not require further upscaling. The original test facility was built in the late 1990´s as a part of an EU project and has been continuously extended and adjusted to new test requirements ever since. The facility offers a unique infrastructure for the technology’s research and is operated by the Spanish CIEMAT (Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas).