Spiros is the Director of the Industrial, Energy and Environmental Systems Lab and he is specialized in renewables, energy efficiency issues and energy saving applications. His research interests include various aspects of renewables (assessment and implementation of technologies and especially photovoltaics and solar thermal systems, implementation of national policies related to renewables and financial and social incentive schemes, renewable energy heating and cooling applications, renewable energy auctions and market exchange, Life Cycle Assessment and environmental impacts analysis from large-scale deployment of renewable energy technologies); Sustainability in the energy sector; Energy saving devices; Technologies of "smart" materials for energy related applications; Energy characterization of building structural  lements. 

As part of his academic work he has published more than 60 papers in international peer-reviewed journals and has been cited more than 2800 times, with a current h-index of 30; additionally, he has actively articipated in more than 50 research projects. He has presented papers to numerous international energy related  conferences and acted as referee for international journals in the area of Renewables, Energy efficiency and Energy policy, while on the same time he has served as member in various professional and academic associations such as the International Association for Energy Economics and the International Solar Energy Society. Additionally he has provided lectures and supervised MSc theses in various academic institutions including ESCP London, EADA Spain and Montpellier Business School. Spiros is the President of the Hellenic Association for Energy Economics..

Spiros is member of the top 2% of the world's top scientists for 2022 in the field of Energy, according to the ''World’s Top 2% Scientists'' ranking published by Stanford University.