Recent developments in electricity generation by Microbial Fuel Cell using different substrates Rahul Sarma, Abhinova Tamuly, Biraj Kumar Kakati ⇑ Department of Energy, Tezpur University, Tezpur 784 028, India article info Article history: Available online 12 March 2021 Keywords: Microbial Fuel Cell Solid substrate Liquid substrate abstract The rise in electrical energy demand and environmental concern results in shifting the world’s focus towards sustainable energy sources. Over-reliance of conventional fossil fuel-based power generation can be combatted using new and potential technologies like Microbial Fuel cells (MFCs). Direct conver- sion of chemical energy to electrical energy by the application of the naturally found microorganisms, makes MFC more convenient source of energy generation. Despite having low power density, it has been able to grab the researcher’s attention due to the flexibility of usage of various organic substrates. This review discusses the various households and industrial waste substrate which has further potential to generate power. The various liquid and solid substrates have been analysed and summarized. The sub- strate used, power densities, reactor volumes and specific important features used by the researchers for the improved performance have been tabulated. In a higher number of researches, liquid substrates have been comparatively more used than that of the solid substrates. Ease of handling, storage and acces- sibility of the liquid waste could be one of the few reasons for it. Also, in this review, various components, and key factors for the experimental design of MFC has been discussed. Along with that losses associated with MFCs and its application is explored. Ó 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Confer- ence on Advancement in Materials, Manufacturing and Energy Engineering (ICAMME-2021). 1. Introduction In the present era, the world is facing a huge energy crisis as the energy demand is continuously increasing at an unsustainable pace [1]. The Nobel laureate Late Richard Smalley often said that ‘‘energy is the single greatest challenge facing humanity”. The fos- sil fuel has been the main source of energy since decades and is in the verge of extinction. It will not certainly run out suddenly, but it is a finite resource. As the supplies of fossil fuels are gradually decreasing and concerns about the increase in CO 2 level in the atmosphere is increasing rapidly, new sources of energy from renewable, carbon-neutral sources with minimal adverse impact on the environment are needed [2]. There is exponential growth in research and development of renewable energy, including solar, wind, hydro, geothermal, tidal and biomass. But there is currently no individual source of renewable energy capable of fully replacing and competing with the source of fossil fuel energy. However, hybrid technology can become a breakthrough for complete elim- ination of the conventional sources of energy [3]. Microbial fuel cell (MFC) is one of the less explored, high poten- tial scope in the field of renewable energy generation. Microbes found in the biomass are tremendously making the dream of low-cost power generation turn into reality. The electrical current generation by bacteria was firstly discovered by Potter in 1911, but it just remained in the paper and was less emphasized for real implementation and practical advancement. Later in the 1990s, it became more of interest and taken up as an opportunity to be an alternative way of power generation by renewable energy resource [4]. MFC is a bioreactor which converts the chemical energy pre- sent in the biomass or organic compounds into electrical energy through the catalytic reaction by the help of microorganism under specific controlled condition. MFC can be a potential alternative to the conventional anaerobic digestion. The output of the anaerobic digestion is in the form of methane and hydrogen gas but almost 65% of the energy is being lost in the process of biogas combustion and conversion into electricity [5]. Along with that, to get the opti- mum electrical energy efficiency from the electric generator, the impurities such as hydrogen sulfide must be removed. Whereas, https://doi.org/10.1016/j.matpr.2021.02.522 2214-7853/Ó 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Advancement in Materials, Manufacturing and Energy Engineering (ICAMME-2021). ⇑ Corresponding author. E-mail address: bkakati@tezu.ernet.in (B.K. Kakati). Materials Today: Proceedings 49 (2022) 457–463 Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr