The first ten years of professional activity in CIEMAT (1992-2003) were focused in the field of Nuclear Safety, collaborating and contributing to projects (Spanish and III, IV and V FP of European Union) aimed at better modeling of the physical phenomena taken place under severe accident in nuclear power plants. In 2003, he joined the Renewable Energy Division in CIEMAT, working on developing and modeling solar radiation for solar power plants. He works on several R&D projects and collaborates with several companies in providing solar data and consultancy. The main activities in solar resource knowledge include satellite-derived models, atmospheric aerosols, spectral measurements and modeling, solar potential mapping and modeling solar systems (PV and CSP plant performance). He was a cofounder of spin-off IRSOLAV (a company offering solar data and consultancy services for about 10 years), and a member of the scientific committee during its first two years. He is a regular reviewer of well-known journals in the field; he is also editor in energies and remote sensing, from MDPI editorial. He is an editorial board member and section board member in the Energies journal. He has been and is still involved in many activities, as an expert, from IEA tasks (task 36 SHC Task 46 SHC and Task 16 PVPS) and as an active collaborator in solar resource assessment developments.