The editorial team of Energies (ISSN: 1996-1073) is pleased to announce the winners of the 2021 Outstanding Reviewer Award:

Name: Prof. Dr. Elena Lucchi
Affiliation: Eurac Research, Institute for Renewable Energy, Bolzano, Italy
Research Interests: energy efficiency; energy audit; building energy simulation; highly efficient materials; renewable energy sources; BIPV

Name: Prof. Dr. Marcin Dębowski
Affiliation: Department of Environmental Engineering, Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
Research Interests: algae cultivation technologies; algae acquisition from natural water; algae biomass separation and dewatering; algae to biofuels; algae to valuable products; methane fermentation; biohydrogen, biodiesel, wastewater treatment; sludge management

Name: Dr. Miroslav Variny
Affiliation: Department of Chemical and Biochemical Engineering, Slovak University of Technology in Bratislava, 812 37 Bratislava, Slovakia
Research Interests: process modeling and intensification; energy auditing; carbon footprint reduction; refining and petrochemistry; renewables

Name: Dr. Piotr F. Borowski
Affiliation: Institute of Mechanical Engineering, Warsaw University of Life Sciences, Warsaw, Poland
Research Interests: management and strategic management; power plants; sustainable development; eco-innovations; eco-efficiency; nexus water–energy–food; CO₂ emission reduction

Name: Dr. Vedran Mrzljak
Affiliation: Faculty of Engineering, University of Rijeka, Rijeka, Croatia
Research Interests: power plants; steam and gas turbines; internal combustion engines; marine power systems