Energies 2021, 14, 6353. https://doi.org/10.3390/en14196353 www.mdpi.com/journal/energies Article Optimal Location-Allocation of Printing Devices for Energy Saving Using a Novel MILP Approach Przemysław Kaszyński 1, *, Pablo Benalcazar 1, *, Piotr Pałka 2 , Roman Rój 3 and Marcin Malec 1 1 Mineral and Energy Economy Research Institute of the Polish Academy of Sciences, Division of Energy Economics, ul. J. Wybickiego 7A, 31-261 Kraków, Poland; malec@min-pan.krakow.pl 2 Warsaw University of Technology, Faculty of Electronics and Information Technology, Institute of Control and Computation Engineering, 00-665 Warsaw, Poland; piotr.palka@pw.edu.pl 3 CTO, Bluebrain, ul. ks. Franciszka Trockiego 22, 30-394 Kraków, Poland; roman.roj@bluebrain.pl * Correspondence: kaszynski@min-pan.krakow.pl (P.K.); benalcazar@min-pan.krakow.pl (P.B.) Abstract: In recent years, a growing number of enterprises have taken different steps to reduce the energy consumption and carbon emissions of information and communication technology (ICT) as- sets. Because of the expansion of digitalization and the need for rapid access to information, enter- prises have been compelled to optimize the location and utilization of their ICT hardware. In this context, this paper presents a novel method based on a mixed-integer linear programming approach for optimizing the physical location and task allocation of printing devices in office floor plans con- sidering the power usage of the ICT assets, the costs related to the purchase and service of the indi- vidual devices, operating costs, and distance between employees and printing devices. The applica- bility of the proposed model is illustrated using the case study of a company with 100 functional departments located in several office buildings across Poland. The results reveal that the model guarantees the execution of all printing tasks and satisfies the functionality requirements expressed by the users of the workstations. Moreover, the selection of more energy-efficient printing devices leads to a considerable reduction in electricity consumption, related not only to the direct operation of these devices but also to their modes of operation (work, idle, or sleep). Such results also bring tangible effects in reducing carbon dioxide emissions, which is particularly important for businesses operating in countries where fossil fuels still dominate the energy mix. Keywords: optimization; modelling; information and communication technology; printers; location analysis 1. Introduction The challenges posed by global warming have increasingly incited governments to implement new policies, regulations, and tools that would accelerate the decarbonization of the power industry and other economic sectors. In the last decades, a variety of policy actions have been taken in the European Union and other developed economies to sup- port the green digital transformation of the tertiary or service sector (e.g., communica- tions, transport, finance, trade, and others). Furthermore, various mechanisms have been employed in the EU to expand the use of renewable electricity technologies in households and businesses and increase the energy efficiency of services (reduce energy consump- tion). In the European Union, carbon emission pricing has been an effective instrument for incentivizing the energy transformation of the tertiary sector and preventing green- house gas emissions. Nowadays, businesses account for the fact that electricity bills play a major role in the financial success of their operations. Therefore, companies operating in this sector frequently look for novel methods and solutions that would further increase their energy efficiency, reduce operating costs, and pave the way for a more sustainable operation. In some EU Member States, the application of innovative solutions has become Citation: Kaszyński, P.; Benalcazar, P.; Pałka, P.; Rój, R.; Malec, M. Optimal Location- Allocation of Printing Devices for Energy Saving Using a Novel MILP Approach. Energies 2021, 14, 6353. https://doi.org/10.3390/en14196353 Academic Editors: Georgios Christoforidis, José Antonio Domínguez-Navarro and Andrzej Karbowski Received: 12 July 2021 Accepted: 30 September 2021 Published: 5 October 2021 Publisher’s Note: MDPI stays neu- tral with regard to jurisdictional claims in published maps and institu- tional affiliations. Copyright: © 2021 by the authors. Li- censee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and con- ditions of the Creative Commons At- tribution (CC BY) license (https://cre- ativecommons.org/licenses/by/4.0/).