PNNL

Alex Vlachokostas is a research engineer in the Building & Connected Systems group. His research interests include energy modeling, energy efficiency, connected devices in residential buildings, and transactive energy. He received his bachelor’s degree in electrical and computer engineering from the National Technical University of Athens in Athens, Greece. Then, he pursued his MS in Sustainability at City College of the City University of New York and participated in the college's Solar Decathlon project sponsored by the Department of Energy. Followed by the MS, Alex continued his studies to pursue a PhD in Electrical Engineering.

During his PhD studies, he interned with private engineering companies and national laboratories, which helped him advance his all-round education in building energy systems. Alex is always interested in innovative low-cost/high-impact projects that can reduce energy consumption in both residential and commercial buildings.

• Energy modeling & simulation
• Energy efficiency
• Sensor prototype development
• Transactive energy

• Ph.D., Electrical Engineering, City College of City University of New York, 2016
• M.S., Sustainability in the Urban Environment, City College of City University of New York , 2011
• B.Eng., Electrical and Computer Engineering, National Technical University of Athens, 2009

• U.S. Patent No. 11,068,545, July 20, 2021, "SPATIAL IDENTIFICATION OF ASSETS USING N-DIMENSIONAL ASSET IDENTIFIERS".

2025

• Liu S., E. Vlachokostas, and E. Kontou. 2025. "Leveraging electric vehicles as a resiliency solution for residential backup power during outages." Energy 318. PNNL-SA-186168. doi:10.1016/j.energy.2025.134613
• Liu S., E. Vlachokostas, and E. Kontou. 2025. "Resilience and environmental benefits of electric school buses as backup power for educational functions continuation during outages." Building and Environment 269, no. _:Art. No. 112329. PNNL-SA-205564. doi:10.1016/j.buildenv.2024.112329

2024

• Biswas S., C. Holland, E. Vlachokostas, S. Nekkalapu, R.L. Kini, and S. Sridhar. 2024. "A Stochastic Framework for Estimating Load Profiles at EV Fast Charging Stations." In IEEE Power & Energy Society General Meeting (PESGM 2024), July 21-25, 2024, Seattle, WA, 1-5. Piscataway, New Jersey:IEEE. PNNL-SA-192613. doi:10.1109/PESGM51994.2024.10689042
• Liu S., E. Vlachokostas, C. Si, and E. Kontou. 2024. "Coupled management of electric vehicle workplace charging and office building loads." Transportation Research. Part D: Transport and Environment 134, no. _:Art. No. 104317. PNNL-SA-182605. doi:10.1016/j.trd.2024.104317

2023

• Kini R.L., S. Hanif, W.S. Wiser, and E. Vlachokostas. 2023. "Turbine-based Power System Tool." In IEEE National Aerospace and Electronics Conference (NAECON 2023), August 28-31, 2023, Dayton, OH, 16-21. Piscataway, New Jersey:IEEE. PNNL-SA-189700. doi:10.1109/NAECON58068.2023.10365910

2022

• Pease L.F., T. Salsbury, K.K. Anderson, R.M. Underhill, J.E. Flaherty, E. Vlachokostas, and C. Burns, et al. 2022. "Size Dependent Infectivity of SARS-CoV-2 via Respiratory Droplets Spread through Central Ventilation Systems." International Communications in Heat and Mass Transfer 132. PNNL-SA-161825. doi:10.1016/j.icheatmasstransfer.2021.105748
• Rosenberg S.I., and E. Vlachokostas. 2022. "Load Shifting with Space Conditioning Heat Pumps During Heating Season in the Pacific Northwest." In Proceedings of the 15th International Conference on Thermal Performance of the Exterior Envelopes of Whole Buildings (Buildings XV), December 5-8, 2022, Clearwater Beach, FL, 427 - 434. Peachtree Corners, Georgia:American Society of Heating Refrigerating and Air-Conditioning Engineers (ASHRAE). PNNL-SA-178436.
• Vlachokostas E., C. Burns, T. Salsbury, R.C. Daniel, D.P. James, J.E. Flaherty, and N. Wang, et al. 2022. "Experimental Evaluation of Respiratory Droplet Spread to Rooms Connected by a Central Ventilation System." Indoor Air 32, no. 1:Art. No. e12940. PNNL-SA-162537. doi:10.1111/ina.12940

2021

• Pease L.F., N. Wang, T. Salsbury, R.M. Underhill, J.E. Flaherty, E. Vlachokostas, and G.R. Kulkarni, et al. 2021. "Investigation of Potential Aerosol Transmission and Infectivity of SARS-CoV-2 through Central Ventilation Systems Building and Environment." Building and Environment 197. PNNL-SA-156558. doi:10.1016/j.buildenv.2021.107633

2020

• Alva M.E., E. Vlachokostas, and N. Madamopoulos. 2020. "Experimental demonstration and performance evaluation of a complex fenestration system for daylighting and thermal harvesting." Solar Energy 197. PNNL-SA-144824. doi:10.1016/j.solener.2020.01.012
• Vlachokostas E., M.E. Poplawski, and S.G. Gourisetti. 2020. "IS BLOCKCHAIN A SUITABLE TECHNOLOGY FOR ENSURING THE INTEGRITY OF DATA SHARED BY LIGHTING AND OTHER BUILDING SYSTEMS?." In IEEE Resilience Week (RWS 2020), October 19-23, 2020, Salt Lake City, UT, 47-152. Piscataway, New Jersey:IEEE. PNNL-SA-150298. doi:10.1109/RWS50334.2020.9241309
• Wang P., M.R. Brambley, M.E. Poplawski, M. Myer, J. Lian, R.G. Lutes, and S. Huang, et al. 2020. "Characterization of Connected Lighting System Potential for Grid Services Under Real-Time Pricing." In 2020 Building Performance Analysis Conference and SimBuild, September 29-October 1, 2020, (Virtual), 27-34. Atlanta, Georgia:ASHRAE. PNNL-SA-150138.

2019

• Papadopoulos S., C.E. Kontokosta, E. Vlachokostas, and E. Azar. 2019. "Rethinking HVAC temperature setpoints in commercial buildings: The potential for zero-cost energy savings and comfort improvement in different climates, Building and Environment." Building and Environment 155. PNNL-SA-144814. doi:10.1016/j.buildenv.2019.03.062
• Vlachokostas E., J. Prousalidis, D. Spathis, M. Nikitas, T. Kourmpelis, S. Dallas, and Z. Soghomonian, et al. 2019. "Ship-to-grid integration: Environmental mitigation and critical infrastructure resilience." In IEEE ELECTRIC SHIP TECHNOLOGIES SYMPOSIUM (ESTS 2019), August 14-16, 2019, Washington, DC, 542-547. Piscataway, New Jersey:IEEE. PNNL-SA-144474. doi:10.1109/ESTS.2019.8847858
• Wang N., E. Vlachokostas, M.I. Borkum, H. Bergmann, and S. Zaleski. 2019. "Unique Building Identifier: A Natural Key for Building Data Matching and its Energy Applications." Energy and Buildings 184. PNNL-SA-132556. doi:10.1016/j.enbuild.2018.11.052

2018

• Goel S., J.C. Gonzalez Matamoros, E. Vlachokostas, and N. Wang. 2018. "Food Service Building Asset Rating Methodology and Analysis." In 2018 ASHRAE Annual Conference, June 23-27, 2018, Houston, TX, Paper No. HO-18-C045. Atlanta, Georgia:American Society of Heating, Refrigerating and Air-Conditioning Engineers. PNNL-SA-132795.