# AC vs. DC Distribution Efficiency: Are We on the Right Path?

^{1}

^{2}

^{3}

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Critique of Various Parameters of AC–DC Distribution System Efficiency

#### 2.1. Critical Review of Load Models Presented in the Past

#### 2.2. Critical Review of the Consideration of PEC Efficiency

#### 2.3. Review of the Consideration of Storage Elements in AC and DC Distribution Studies

#### 2.4. The Choice of Voltage Level in DC Distribution Efficiency Analyses

#### 2.5. Consideration of Line Losses in the Past AC/DC Distribution Efficiency Studies

#### 2.6. Employment of Distributed Generation in AC/DC Distribution Efficiency Studies

_{at}’, ‘E

_{bt}’, and so forth. The denominator sums the overall PV generation.

## 3. An Approach to a Definite AC/DC Distribution System

- Conventional/classical,
- Shifting trend,
- Futuristic.

#### 3.1. Inclusion of PEC Efficiency in System Model

- Loads with a similar rating are lumped and driven by a single converter,

#### 3.2. Inclusion of Storage Elements in System Model

#### 3.3. Selection of Voltage Level in System Model

#### 3.4. Line Loss Consideration

#### 3.5. Inclusion of DG in System Model

## 4. The Future of AC–DC Efficiency Comparison

_{L}’, and solar capacity ‘C’. When the values of these variables are 0.1 pu each, we can consider this state as S1. The variables ‘α’, ‘β’, and ‘γ’ represent the increment and decrement in the values of ‘Ps’, ‘P

_{L}’, and ‘C’, respectively. With an increment in ‘α’ and ‘β’ for the values of ‘Ps’ and ‘P

_{L}’, the system shifts to a new state S6 and vice versa. Similarly, while the system is in S1, an increment in Ps alone would move the system to S2. Figure 9 is an illustration of how the system shifts states as a function of the variation in the values of system parameters; accordingly, the energy savings for all states can be determined in the future for a comprehensive analysis of AC and DC systems.

## 5. Further Research Areas

#### 5.1. Case of Electric Vehicle Penetration

#### 5.2. Economics of Shift from AC to DC systems

## 6. Miscellaneous Topics of Discussion

#### 6.1. Applications That May Inherently Require AC Machines

#### 6.2. Migration from AC to DC

#### 6.3. Hurdles in Shifting from AC to DC Systems

## 7. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Conflicts of Interest

## References

- Gelani, H.E.; Dastgeer, F. Efficiency analyses of a DC residential power distribution system for the modern home. Adv. Electl. Comp. Eng.
**2015**, 15, 135–143. [Google Scholar] [CrossRef] - Hammerstrom, D.J. AC versus DC distribution systems: Did we get it right? In Proceedings of the 2007 IEEE Power Engineering Society General Meeting, Tampa, FL, USA, 24–28 June 2007; pp. 1–5. [Google Scholar] [CrossRef]
- Starke, M.; Tolbert, L.; Ozpineci, B. AC vs. DC distribution: A loss comparison. In Proceedings of the 2008 IEEE/PES Transmission and Distribution Conference and Exposition; Institute of Electrical and Elec-tronics Engineers (IEEE), Bogota, Colombia, 13–15 August 2008; pp. 1–7. [Google Scholar]
- Vossos, V.; Garbesi, K.; Shen, H. Energy savings from direct-DC in U.S. residential buildings. Energy Build.
**2014**, 68, 223–231. [Google Scholar] [CrossRef] - Dastgeer, F.; Gelani, H.E. A Comparative analysis of system efficiency for AC and DC residential power distribution para-digms. Energy Build.
**2017**, 138, 648–654. [Google Scholar] [CrossRef] - Dastgeer, F.; Kalam, A. Efficiency comparison of DC and AC distribution systems for distributed generation. In Proceedings of the IEEE Power Engineering Conference, Adelaide, Australia, 27–30 September 2009. [Google Scholar]
- Amin, M.; Arafat, Y.; Lundberg, S.; Mangold, S. Low voltage DC distribution system compared with 230 V AC. In Proceedings of the 2009 IEEE Electrical Power & Energy Conference (EPEC), Montreal, QC, Canada, 22–23 October 2009; pp. 340–345. [Google Scholar]
- Pratt, A.; Kumar, P.; Aldridge, T.V. Evaluation of 400V DC distribution in telco and data centers to improve energy efficiency. In Proceedings of the INTELEC 29th International Telecommunications Energy Conference, Rome, Italy, 30 September–4 October 2007; pp. 32–39. [Google Scholar]
- Engelen, K.; Shun, E.L.; Vermeyen, P.; Pardon, L.; D’hulst, R.; Driesen, J.; Belmans, R. The feasibility of small-scale residential DC distribution systems. Proceedings of IECON 2006-32nd Annual Conference on IEEE Industrial Electronics, Paris, France, 7–10 November 2006. [Google Scholar]
- Nilsson, D.; Sannino, A. Efficiency analysis of low- and medium-voltage dc distribution systems. In Proceedings of the Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications, Sydney, NSW, Australia, 30 August–2 September 2004; Volume 2, pp. 2315–2321. [Google Scholar]
- Becker, D.J.; Sonnenberg, B. DC microgrids in buildings and data centers. In Proceedings of the 2011 IEEE 33rd International Telecommunications Energy Conference (INTELEC); Institute of Electrical and Electronics Engineers (IEEE), Amsterdam, The Netherlands, 9–13 October 2011; pp. 1–7. [Google Scholar]
- Liu, Z.; Li, M. Research on energy efficiency of DC distribution system. AASRI Procedia
**2014**, 7, 68–74. [Google Scholar] [CrossRef] - Brenguier, J.; Vallet, M.; Vaillant, F. Efficiency gap between AC and DC electrical power distribution system. Proceedings of 2016 IEEE/IAS 52nd Industrial and Commercial Power Systems Technical Conference (I&CPS), Detroit, MI, USA, 1–5 May 2016. [Google Scholar]
- Fregosi, D.; Ravula, S.; Brhlik, D.; Saussele, J.; Frank, S.; Bonnema, E.; Scheib, J.; Wilson, E. A comparative study of DC and AC microgrids in commercial buildings across different climates and operating profiles. In Proceedings of the 2015 IEEE First International Conference on DC Microgrids (ICDCM), Atlanta, GA, USA, 7–10 June 2015; pp. 159–164. [Google Scholar]
- Atia, H.R.; Shakya, A.; Tandukar, P.; Tamrakar, U.; Hansen, T.M.; Tonkoski, R. Efficiency analysis of AC coupled and DC coupled microgrids considering load profile variations. In Proceedings of the 2016 IEEE International Conference on Electro Information Technology (EIT), Grand Forks, ND, USA, 19–21 May 2016. [Google Scholar]
- Sannino, A.; Postiglione, G.; Bollen, M. Feasibility of a DC network for commercial facilities. IEEE Trans. Ind. Appl.
**2003**, 39, 1499–1507. [Google Scholar] [CrossRef] - Manandhar, U.; Ukil, A.; Jonathan, T.K.K. Efficiency comparison of DC and AC microgrid. In Proceedings of the 2015 IEEE Innovative Smart Grid Technologies-Asia (ISGT ASIA), Bangkok, Thailand, 3–6 November 2015. [Google Scholar]
- Sirsi, R.; Ambekar, Y. Efficiency of DC microgrid on DC distribution system. In Proceedings of the 2015 IEEE Innovative Smart Grid Technologies-Asia (ISGT ASIA), Bangkok, Thailand, 3–6 November 2015. [Google Scholar]
- Sirsi, R.; Prasad, S.; Sonawane, A.; Lokhande, A. Efficiency comparison of AC distribution system and DC distribution system in microgrid. In Proceedings of the 2016 International Conference on Energy Efficient Technologies for Sustainability (ICEETS); Institute of Electrical and Electronics Engineers (IEEE), Nagercoil, India, 7–8 April 2016; pp. 325–329. [Google Scholar]
- Boeke, U.; Wendt, M. DC power grids for buildings. In Proceedings of the 2015 IEEE First International Conference on DC Microgrids (ICDCM), Atlanta, GA, USA, 9–10 June 2015; pp. 210–214. [Google Scholar]
- Weiss, R.; Ott, L.; Boeke, U. Energy efficient low-voltage DC-grids for commercial buildings. In Proceedings of the 2015 IEEE First International Conference on DC Microgrids (ICDCM), Atlanta, GA, USA, 9–19 June 2015. [Google Scholar]
- Gerber, D.L.; Vossos, V.; Feng, W.; Marnay, C.; Nordman, B.; Brown, R. A simulation-based efficiency comparison of AC and DC power distribution networks in commercial buildings. Appl. Energy
**2018**, 210, 1167–1187. [Google Scholar] [CrossRef] [Green Version] - Glasgo, B.; Azevedo, I.L.; Hendrickson, C. How much electricity can we save by using direct current circuits in homes? Under-standing the potential for electricity savings and assessing feasibility of a transition towards DC powered buildings. Appl. Energy
**2016**, 180, 66–75. [Google Scholar] [CrossRef] [Green Version] - Chauhan, R.; Rajpurohit, B. DC distribution system for energy efficient buildings. In Proceedings of the 2014 Eighteenth National Power Systems Conference (NPSC), Guwahati, India, 18–20 December 2014. [Google Scholar]
- Goikoetxea, A.; Canales, J.M.; Sanchez, R.; Zumeta, P.; Sanchez, R. DC versus AC in residential buildings: Efficiency comparison. In Proceedings of the Eurocon 2013, Zagreb, Croatia, 1–4 July 2013; pp. 1–5. [Google Scholar]
- Nasir, M.; Zaffar, N.A.; Khan, H.A. Analysis on central and distributed architectures of solar powered DC microgrids. In Proceedings of the 2016 Clemson University Power Systems Conference (PSC), Clemson, SC, USA, 8–11 March 2016; pp. 1–6. [Google Scholar]
- Nasir, M.; Khan, H. Solar photovoltaic integrated building scale hybrid AC/DC microgrid. In Proceedings of the 5th IET International Conference on Renewable Power Generation (RPG) 2016, London, UK, 21–23 September 2016; p. 7. [Google Scholar]
- Nasir, M.; Khan, H.A.; Hussain, A.; Mateen, L.; Zaffar, N.A. Solar PV-based scalable DC microgrid for rural electrification in developing regions. IEEE Trans. Sustain. Energy
**2018**, 9, 390–399. [Google Scholar] [CrossRef] - Nasir, M.; Iqbal, S.; Khan, H.A. Optimal planning and design of low-voltage low-power solar DC microgrids. IEEE Trans. Power Syst.
**2018**, 33, 2919–2928. [Google Scholar] [CrossRef] - Farrag, M.E.; Haggag, A.; Farooq, H.; Ali, W. Analysis and mitigation of harmonics caused by air conditioners in a distribution system. In Proceedings of the 2017 Nineteenth International Middle East Power Systems Conference (MEPCON), Cairo, Egypt, 19–21 December 2017; pp. 702–707. [Google Scholar]
- Liu, M.; Yong, J.; Wang, X.; Lu, J. A new event detection technique for residential load monitoring. In Proceedings of the 2018 18th International Conference on Harmonics and Quality of Power (ICHQP), Ljubljana, Slovenia, 13–16 May 2018; pp. 1–6. [Google Scholar]
- Estes, H.; Santoso, S. Profiles, harmonics, and transient analysis of 240 V air conditioning load during peak demand. In Proceedings of the 2016 IEEE Power and Energy Society General Meeting (PESGM), Boston, MA, USA, 17–21 July 2016; pp. 1–5. [Google Scholar]
- Fazli, T.; Yeap, R.Y.; Stephens, B. Modeling the energy and cost impacts of excess static pressure in central forced-air heating and air-conditioning systems in single-family residences in the U.S. Energy Build.
**2015**, 107, 243–253. [Google Scholar] [CrossRef] - Rathikrindi, K.S.; Paramasivam, S.; Sandeep, L. Energy saving opportunities through Variable Frequency Drive for Commercial Air Conditioners. In Proceedings of the 2018 4th International Conference on Electrical Energy Systems (ICEES), Chennai, India, 7–9 February 2018; pp. 338–340. [Google Scholar]
- Wang, G.; Song, L. Performance assessment of variable frequency drives in heating, ventilation, and air-conditioning systems. Sci. Technol. Built Environ.
**2018**, 24, 1075–1083. [Google Scholar] [CrossRef] - Lim, J.; Yoon, M.S.; Al-Qahtani, T.; Nam, Y. Feasibility study on variable-speed air conditioner under hot climate based on real-scale experiment and energy simulation. Energies
**2019**, 12, 1489. [Google Scholar] [CrossRef] [Green Version] - Khatri, R.; Joshi, A. Energy Performance comparison of inverter based variable refrigerant flow unitary AC with constant volume unitary AC. Energy Procedia
**2017**, 109, 18–26. [Google Scholar] [CrossRef] - Dongellini, M.; Abbenante, M.; Morini, G. A strategy for the optimal control logic of heat pump systems: Impact on the energy consumptions of a residential building. In Proceedings of the 12th IEA Heat Pump Conference 2017, Rotterdam, The Netherlands, 15–18 May 2017. [Google Scholar]
- Kazakbaev, V.; Prakht, V.; Dmitrievskii, V.; Ibrahim, M.N.; Oshurbekov, S.; Sarapulov, S. Efficiency analysis of low electric power drives employing induction and synchronous reluctance motors in pump applications. Energies
**2019**, 12, 1144. [Google Scholar] [CrossRef] [Green Version] - Blaabjerg, F.; Wang, H.; Davari, P.; Qu, X.; Zare, F. Energy Saving and Efficient Energy Use by Power Electronic Systems. In The Interrelationship between Financial and Energy Markets; Springer Science and Business Media: Berlin/Heidelberg, Germany, 2017; Volume 37, pp. 1–14. [Google Scholar]
- Bhatt, D.; Hariharasudan, A.; Lis, M.; Grabowska, M. Forecasting of energy demands for smart home applications. Energies
**2021**, 14, 1045. [Google Scholar] [CrossRef] - Gnaciński, P.; Hallmann, D.; Klimczak, P.; Muc, A.; Pepliński, M. Effects of voltage interharmonics on cage induction motors. Energies
**2021**, 14, 1218. [Google Scholar] [CrossRef] - Lusis, P.; Khalilpour, R.; Andrew, L.; Liebman, A. Short-term residential load forecasting: Impact of calendar effects and forecast granularity. Appl. Energy
**2017**, 205, 654–669. [Google Scholar] [CrossRef] - Das, S.; Das, D.; Patra, A. Distribution network reconfiguration using distributed generation unit considering var-iations of load. In Proceedings of the 2016 IEEE 1st International Conference on Power Electronics, Intelligent Control and Energy Systems (ICPEICES), Delhi, India, 4–6 July 2016. [Google Scholar]
- Gelani, H.E.; Dastgeer, F.; Siraj, K.; Nasir, M.; Niazi, K.A.K.; Yang, Y. Efficiency comparison of AC and DC distribution networks for modern residential localities. Appl. Sci.
**2019**, 9, 582. [Google Scholar] [CrossRef] [Green Version] - Fischer, D.; Surmann, A.; Lindberg, K.B. Impact of emerging technologies on the electricity load profile of residential areas. Energy Build.
**2020**, 208, 109614. [Google Scholar] [CrossRef] - Villa, G.; Gomez-Aleixandre, C.; Garcia, P.; Garcia, J. Distributed Control alternatives of modular power converters for hybrid DC/AC microgrids. In Proceedings of the 2018 IEEE Energy Conversion Congress and Exposition (ECCE), Portland, OR, USA, 23–27 September 2018; pp. 6379–6386. [Google Scholar]
- Shekhar, A.; Kontos, E.; Ramirez-Elizondo, L.; Rodrigo-Mor, A.; Bauer, P. Grid capacity and efficiency enhancement by op-erating medium voltage AC cables as DC links with modular multilevel converters. Int. J. Electr. Power Energy Syst.
**2017**, 93, 479–493. [Google Scholar] [CrossRef] - Acharya, A.B.; Sera, D.; Teodorescu, R.; Norum, L.E. Modular multilevel converter for photovoltaic application with high energy yield under uneven irradiance. Energies
**2020**, 13, 2619. [Google Scholar] [CrossRef] - Arunkumari, T.; Indragandhi, V. An overview of high voltage conversion ratio DC-DC converter configurations used in DC micro-grid architectures. Renew. Sustain. Energy Rev.
**2017**, 77, 670–687. [Google Scholar] [CrossRef] - Mbinkar, E.N.; Asoh, D.A.; Tchuidjan, R.; Baldeh, A. Design of a photovoltaic mini-grid system for rural electrification in Sub-Saharan Africa. Energy Power Eng.
**2021**, 13, 91–110. [Google Scholar] [CrossRef] - Malamaki, K.-N.D.; Demoulias, C.S.; Oureilidis, K.O. Analytical calculation of the PV converter efficiency curve at non-unity power factors. In Proceedings of the 2017 52nd International Universities Power Engineering Conference (UPEC), Heraklion, Crete, Greece, 28–31 August 2017; pp. 1–6. [Google Scholar]
- Zubieta, L.E. Are microgrids the future of energy?: DC microgrids from concept to demonstration to deployment. IEEE Electrif. Mag.
**2016**, 4, 37–44. [Google Scholar] [CrossRef] - Kumar, D.; Zare, F.; Ghosh, A. DC microgrid technology: System architectures, AC grid interfaces, grounding schemes, power quality, communication networks, applications, and standardizations aspects. IEEE Access
**2017**, 5, 12230–12256. [Google Scholar] [CrossRef] - Zadeh, M.; Gavagsaz-Ghoachani, R.; Pierfederici, S.; Nahid-Mobarakeh, B.; Molinas, M. Stability Analysis and dynamic performance evaluation of a power electronics-based DC distribution system with active stabilizer. IEEE J. Emerg. Sel. Top. Power Electron.
**2016**, 4, 93–102. [Google Scholar] [CrossRef] - Nasir, M.; Khan, H.A.; Khan, I.; Hassan, N.U.; Zaffar, N.A.; Mehmood, A.; Sauter, T.; Muyeen, S.M. Grid load reduction through optimized PV power utilization in intermittent grids using a low-cost hardware platform. Energies
**2019**, 12, 1764. [Google Scholar] [CrossRef] [Green Version] - Nasir, M.; Jin, Z.; Khan, H.A.; Zaffar, N.A.; Vasquez, J.C.; Guerrero, J.M. A decentralized control architecture applied to DC nanogrid clusters for rural electrification in developing regions. IEEE Trans. Power Electron.
**2019**, 34, 1773–1785. [Google Scholar] [CrossRef] [Green Version] - Nasir, M.; Khan, H.A.; Niazi, K.A.K.; Jin, Z.; Guerrero, J. Dual-loop control strategy applied to PV/battery-based islanded DC microgrids for swarm electrification of developing regions. J. Eng.
**2019**, 2019, 5298–5302. [Google Scholar] [CrossRef] - Nasir, M.; Khan, H.A.; Zaffar, N.A.; Vasquez, J.C.; Guerrero, J.M. Scalable solar DC Microgrids: On the path to revolutionizing the electrification architecture of developing communities. IEEE Electrif. Mag.
**2018**, 6, 63–72. [Google Scholar] [CrossRef] - Zhang, S.; Huang, P.; Sun, Y. A multi-criterion renewable energy system design optimization for net zero energy buildings under uncertainties. Energy
**2016**, 94, 654–665. [Google Scholar] [CrossRef] - Athienitis, A.; O’Brien, W. Modeling, Design, and Optimization of Net-Zero Energy Buildings; Ernst &Sohn: Berlin, Germany, 2015. [Google Scholar]
- Vieira, F.M.; Moura, P.S.; Almeida, A. Energy storage system for self-consumption of photovoltaic energy in residential zero energy buildings. Renew. Energy
**2017**, 103, 308–320. [Google Scholar] [CrossRef] - Chastas, P.; Theodosiou, T.; Bikas, D. Embodied energy in residential buildings-towards the nearly zero energy building: A literature review. Build. Environ.
**2016**, 105, 267–282. [Google Scholar] [CrossRef] - Dash, V.; Bajpai, P. Power management control strategy for a stand-alone solar photovoltaic-fuel cell–battery hybrid system. Sustain. Energy Technol. Assess.
**2015**, 9, 68–80. [Google Scholar] [CrossRef] - Mehmood, K.K.; Khan, S.U.; Lee, S.; Haider, Z.M.; Rafique, M.K.; Kim, C. Optimal sizing and allocation of battery energy storage systems with wind and solar power DGs in a distribution network for voltage regulation considering the lifespan of batteries. IET Renew. Power Gener.
**2017**, 11, 1305–1315. [Google Scholar] [CrossRef] - Tong, S.; Lacap, J.H.; Park, J.W. Battery state of charge estimation using a load-classifying neural network. J. Energy Storage
**2016**, 7, 236–243. [Google Scholar] [CrossRef] - Zhang, Z.; Cai, Y.-Y.; Zhang, Y.; Gu, D.-J.; Liu, Y.-F. A distributed architecture based on microbank modules with self-reconfiguration control to improve the energy efficiency in the battery energy storage system. IEEE Trans. Power Electron.
**2015**, 31, 304–317. [Google Scholar] [CrossRef] - Siraj, K.; Khan, H.A. DC distribution for residential power networks—A framework to analyze the impact of voltage levels on energy efficiency. Energy Rep.
**2020**, 6, 944–951. [Google Scholar] [CrossRef] - Emerge Alliance. Available online: https://www.emergealliance.org/ (accessed on 12 April 2021).
- He, G.; Kammen, D.M. Where, when and how much solar is available? A provincial-scale solar resource assessment for China. Renew. Energy
**2016**, 85, 74–82. [Google Scholar] [CrossRef] [Green Version] - Raza, M.Q.; Mithulananthan, N.; Summerfield, A. Solar output power forecast using an ensemble framework with neural predictors and Bayesian adaptive combination. Sol. Energy
**2018**, 166, 226–241. [Google Scholar] [CrossRef] - Megahed, T.F.; Radwan, A. Performance investigation of zero-building-integrated photovoltaic roof system: A case study in Egypt. Alex. Eng. J.
**2020**, 59, 5053–5067. [Google Scholar] [CrossRef] - Nair, A.K.; Kirubakaran, V. Increasing solar PV output by controlling environmental parameters. In Proceedings of the 2016 3rd International Conference on Electrical Energy Systems (ICEES), Chennai, India, 17–19 March 2016; pp. 251–256. [Google Scholar]
- Ellahi, M.; Abbas, G.; Khan, I.; Koola, P.M.; Nasir, M.; Raza, A.; Farooq, U. Recent approaches of forecasting and optimal economic dispatch to overcome intermittency of wind and photovoltaic (PV) systems: A review. Energies
**2019**, 12, 4392. [Google Scholar] [CrossRef] [Green Version] - Huld, T.; Amillo, A.M.G. Estimating PV module performance over large geographical regions: The role of irradiance, air temperature, wind speed and solar spectrum. Energies
**2015**, 8, 5159. [Google Scholar] [CrossRef] [Green Version] - Yang, D.; Quan, H.; Disfani, V.R.; Liu, L. Reconciling solar forecasts: Geographical hierarchy. Sol. Energy
**2017**, 146, 276–286. [Google Scholar] [CrossRef] - Al-Sakkaf, S.; Kassas, M.; Khalid, M.; Abido, M.A. An energy management system for residential autonomous DC microgrid using optimized fuzzy logic controller considering economic dispatch. Energies
**2019**, 12, 1457. [Google Scholar] [CrossRef] [Green Version] - Ahmad, F.; Dastgeer, F.; Gelani, H.E.; Khan, S.; Nasir, M. Comparative analyses of residential building efficiency for AC and DC distribution networks. Bull. Pol. Acad. Sci. Tech. Sci.
**2021**, 69, e136732. [Google Scholar] - Montoya, O.D.; Serra, F.M.; De De Angelo, C.H. On the efficiency in electrical networks with AC and DC operation technologies: A comparative study at the distribution stage. Electronics
**2020**, 9, 1352. [Google Scholar] [CrossRef] - Chen, X.; Khan, I. A Tutorial on Current Controlled DC-DC Converter used in Microgrid System. In Proceedings of the 2019 IEEE 16th International Conference on Smart Cities: Improving Quality of Life Using ICT & IoT and AI (HONET-ICT), Charlotte, NC, USA, 6−9 October 2019; pp. 232–234. [Google Scholar]
- Jadeja, R.; Ved, A.; Trivedi, T.; Khanduja, G. Control of power electronic converters in AC microgrid. Numer. Methods Energy Appl.
**2019**, 27, 329–355. [Google Scholar] [CrossRef] - Singh, S. Selection of non-isolated DC-DC converters for solar photovoltaic system. Renew. Sustain. Energy Rev.
**2017**, 76, 1230–1247. [Google Scholar] [CrossRef] - Yau, Y.-T.; Wang, C.-W.; Hwu, K.-I. Light-load efficiency improvement for ultrahigh step-down converter based on skip mode. Electronics
**2021**, 10, 355. [Google Scholar] [CrossRef] - Nasir, M.; Anees, M.; Khan, H.A.; Khan, I.; Xu, Y.; Guerrero, J.M. Integration and decentralized control of standalone solar home systems for off-grid community applications. IEEE Trans. Ind. Appl.
**2019**, 55, 7240–7250. [Google Scholar] [CrossRef] - Nasir, M.; Iqbal, S.; Khan, H.; Vasquez, J.; Guerrero, J. Sustainable rural electrification through solar PV DC microgrids—An architecture-based assessment. Processes
**2020**, 8, 1417. [Google Scholar] [CrossRef] - Iqbal, S.; Nasir, M.; Zia, M.F.; Riaz, K.; Sajjad, H.; Khan, H.A. A novel approach for system loss minimization in a peer-to-peer energy sharing community DC microgrid. Int. J. Electr. Power Energy Syst.
**2021**, 129, 106775. [Google Scholar] [CrossRef] - Dastgeer, F.; Anees, H.M.; Gelani, H.E.; Amjad, K.; Javeed, M.R. A basic mathematical testbed for energy efficiency analyses of DC power distribution systems/microgrids. Bull. Electr. Eng. Inform.
**2021**, 10, 1484–1494. [Google Scholar] [CrossRef] - Zou, Y.; Zhao, J.; Gao, X.; Chen, Y.; Tohidi, A. Experimental results of electric vehicles effects on low voltage grids. J. Clean. Prod.
**2020**, 255, 120270. [Google Scholar] [CrossRef] - Boglou, V.; Karavas, C.-S.; Arvanitis, K.; Karlis, A. A fuzzy energy management strategy for the coordination of electric vehicle charging in low voltage distribution grids. Energies
**2020**, 13, 3709. [Google Scholar] [CrossRef] - Spitzer, M.; Schlund, J.; Apostolaki-Iosifidou, E.; Pruckner, M. Optimized integration of electric vehicles in low voltage distribution grids. Energies
**2019**, 12, 4059. [Google Scholar] [CrossRef] [Green Version] - Barros, J.; de Apráiz, M.; Diego, R.I. Power Quality in DC Distribution Networks. Energies
**2019**, 12, 848. [Google Scholar] [CrossRef] [Green Version] - Staples, J.; Martin, J.; Rajan, S. Standards for the Introduction of Accessible DC Power in Buildings. In Proceedings of the 2019 IEEE Symposium on Product Compliance Engineering (SPCE Austin), Austin, TX, USA, 11–12 November 2019. [Google Scholar]
- Van den Broeck, G.; Stuyts, J.; Driesen, J. A critical review of power quality standards and definitions applied to DC microgrids. Appl. Energy
**2018**, 229, 281–288. [Google Scholar] [CrossRef] - IEEE 946-2020. Available online: https://standards.ieee.org/standard/946-2020.html (accessed on 23 June 2021).
- IEEE 1547. Available online: https://standards.ieee.org/standard/1547-2018.html (accessed on 23 June 2021).
- IEEE DC in a Home. Available online: https://standards.ieee.org/content/dam/ieee-standards/standards/web/governance/iccom/IC13-005-02_DC_in_the_Home.pdf (accessed on 23 June 2021).
- UL Standards. Available online: https://standardscatalog.ul.com/ProductDetail.aspx?productId=UL1741 (accessed on 23 June 2021).

**Figure 1.**Load model of a typical community distribution system [5].

**Figure 2.**Load model for LED loads [14].

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Gelani, H.E.; Dastgeer, F.; Nasir, M.; Khan, S.; Guerrero, J.M.
AC vs. DC Distribution Efficiency: Are We on the Right Path? *Energies* **2021**, *14*, 4039.
https://doi.org/10.3390/en14134039

**AMA Style**

Gelani HE, Dastgeer F, Nasir M, Khan S, Guerrero JM.
AC vs. DC Distribution Efficiency: Are We on the Right Path? *Energies*. 2021; 14(13):4039.
https://doi.org/10.3390/en14134039

**Chicago/Turabian Style**

Gelani, Hasan Erteza, Faizan Dastgeer, Mashood Nasir, Sidra Khan, and Josep M. Guerrero.
2021. "AC vs. DC Distribution Efficiency: Are We on the Right Path?" *Energies* 14, no. 13: 4039.
https://doi.org/10.3390/en14134039