This article summarizes part of the work developed, and already published, in the context of the AMADEUS project (www.amadeusproject. eu), a FET-OPEN project funded by the European Commission to research a new generation of materials and solid state devices for ultra-high temperature energy storage and conversion. New silicon-based alloys as new phase change materials (PCMs) are explored, achieving latent heat in the range of 1000-2000 kWh/m3, which means an order of magnitude greater than that of typical saltbased PCMs used in concentrated solar power (CSP). In addition, silicon-based PCMs lead to storage temperatures well beyond 1000 ºC, and so this project aims at breaking the mark of ~ 600 ºC rarely exceeded by current state of the art thermal energy storage (TES). Furthermore, this article presents the most significant outcomes of work developed to assesses whether it is profitable to store solar photovoltaic (PV) electricity in the form of heat and convert it back to electricity on demand in the residential sector.