The tremendous expansion of the photovoltaic technology and its relative avidity for silicon is producing a dramatic change in the polysilicon industry structure, increasing the efforts to produce a low cost, high quality Solar Silicon. In this context, the Centro de Tecnología del Silicio Solar (CENTESIL) was founded in 2006 as a private-public partnership venture, and is currently building a 50 t/a pilot plant for silicon purification following the chlorosilane route. Although an advanced state of the art technology has been selected as first choice, the purpose is to be able to undertake developments in any topic that has the potential to reduce the cost effectively. Additionally, the project includes facilities for monocrystalline growth and wafering, and also the solar cell processing line of the Instituto de Energía Solar, so that it will cover the whole value chain from feedstock to solar cell