The editorial team of Energies (ISSN: 1996-1073) would like to congratulate the winners of the Energies 2021 Best Paper Award, who were chosen by a selection committee chaired by the Editor-in-Chief, Prof. Dr. Enrico Sciubba. Following a review process by the Award Evaluation Committee, ten review papers were selected as winners. The recipients are as follows:

1. “Recent Progress of Organic Photovoltaics with Efficiency over 17%”
   by Xuelin Wang, Qianqian Sun, Jinhua Gao, Jian Wang, Chunyu Xu, Xiaoling Ma and Fujun Zhang
   Energies 2021, 14(14), 4200; https://doi.org/10.3390/en14144200
   Available online: https://www.mdpi.com/1996-1073/14/14/4200

2. “Critical Review of Flywheel Energy Storage System”
   by Abdul Ghani Olabi, Tabbi Wilberforce, Mohammad Ali Abdelkareem and Mohamad Ramadan
   Energies 2021, 14(8), 2159; https://doi.org/10.3390/en14082159
   Available online: https://www.mdpi.com/1996-1073/14/8/2159

3. “Review of Multilevel Inverters for PV Energy System Applications”
   by Ali Bughneda, Mohamed Salem, Anna Richelli, Dahaman Ishak and Salah Alatai
   Energies 2021, 14(6), 1585; https://doi.org/10.3390/en14061585
   Available online: https://www.mdpi.com/1996-1073/14/6/1585

4. “Methane Cracking for Hydrogen Production: A Review of Catalytic and Molten Media Pyrolysis”
   by Malek Msheik,Sylvain Rodat and Stéphane Abanades
   Energies 2021, 14(11), 3107; https://doi.org/10.3390/en14113107
   Available online: https://www.mdpi.com/1996-1073/14/11/3107

5. “A Review of DC Microgrid Energy Management Systems Dedicated to Residential Applications”
   by Sadaqat Ali, Zhixue Zheng, Michel Aillerie, Jean-Paul Sawicki, Marie-Cécile Péra and Daniel Hissel
   Energies 2021, 14(14), 4308; https://doi.org/10.3390/en14144308
   Available online: https://www.mdpi.com/1996-1073/14/14/4308

6. “Review on Deep Neural Networks Applied to Low-Frequency NILM”
   by Patrick Huber, Alberto Calatroni, Andreas Rumsch and Andrew Paice
   Energies 2021, 14(9), 2390; https://doi.org/10.3390/en14092390
   Available online: https://www.mdpi.com/1996-1073/14/9/2390

7. “CdTe-Based Thin Film Solar Cells: Past, Present and Future”
   by Alessandro Romeo and Elisa Artegiani
   Energies 2021, 14(6), 1684; https://doi.org/10.3390/en14061684
   Available online: https://www.mdpi.com/1996-1073/14/6/1684

8. “Bifacial Photovoltaics 2021: Status, Opportunities and Challenges”
   by Radovan Kopecek and Joris Libal
   Energies 2021, 14(8), 2076; https://doi.org/10.3390/en14082076
   Available online: https://www.mdpi.com/1996-1073/14/8/2076

9. “Comprehensive Review on Fuel Cell Technology for Stationary Applications as Sustainable and Efficient Poly-Generation Energy Systems”
   by Viviana Cigolotti, Matteo Genovese and Petronilla Fragiacomo
   Energies 2021, 14(16), 4963; https://doi.org/10.3390/en14164963
   Available online: https://www.mdpi.com/1996-1073/14/16/4963

10. “Integrated Approach for Wastewater Treatment and Biofuel Production in Microalgae Biorefineries”
    by Sanjeet Mehariya, Rahul Kumar Goswami, Pradeep Verma, Roberto Lavecchia and Antonio Zuorro
    Energies 2021, 14(8), 2282; https://doi.org/10.3390/en14082282
    Available online: https://www.mdpi.com/1996-1073/14/8/2282