# Portable Prototype of Hydrogen Fuel Cells for Educational Training
## 1 Introduction  
The history of fuel cells (FC) goes back to the 1800s when [PERSON] and [PERSON] first described the electrolysis process. In 1839, [PERSON] was credited with the first fuel cell [1]. He made a \"Gas Battery,\" which consists of separate platinum electrodes submerged in a sulfuric acid electrolyte solution. The gas battery produced 12 amps and 1.8 volts [2]. [PERSON] described the theoretical understanding of FC and explained FC components' roles in 1893 [3]. Using coal-derived gas, [PERSON] performed experiments on FC in 1889 and utilized platinum as an electrode [4]. The output parameters achieved by this FC were 0.73 V and 6 Ampere per square foot [5, 6]. [PERSON] and [PERSON] developed a similar fuel cell, but these cells had the problem of leaking gases from one chamber to another [7]. That is why they produced a voltage of less than 1 to meet the electricity needs. [PERSON] and [PERSON] (1832-1913) [8] also thought that the fuel cell electrochemical process lacks practicality due to needing costly metals, and coal was inexpensive, so it was impossible to develop a new system with higher efficiency with less electricity cost [9]. In the early 1900s, [PERSON] performed experimentation on various FC types, especially on high-temperature FC [10]. This work led to FC types being researched for these days, such as Molten Carbonate Fuel Cell (MCFC) and Solid Oxide Fuel Cell (SOFC) devices [11].  
Current energy sources primarily depend on fossil fuels [12, 13]. However, due to technological advancements, energy demand is increasing while fossil fuels are depleting due to their limited supply resulting in a considerable energy gap. As per IEA, during the last two decades, an increase of 49% in energy demand has been observed [14, 15]. Moreover, all emerging economies depend on their energy sector for development [16]. To meet this energy demand, keeping in view fossil fuel depletion, the focus these days is toexplore renewable energy technologies such as hydrogen energy, solar energy, bioenergy, etc. Although solar and wind energies are renewable, they are intermittent and not dispatchable [17]. Solar photovoltaics and wind energy system often require energy storage elements to mitigate intermittency, stabilize the power system, and improve the utilization rate [18]. Fuel cells are dispatchable, and their system is less complex. Hydrogen can be produced from water through electrolysis and used as fuel in fuel cells for electricity production or power in fuel cell-based vehicles [16]. In 2022, the total market size of hydrogen energy was USD 136 billion, giving rise to the creation of more than 10,000 new jobs [19]. The hydrogen economy has the potential to lead the energy sector in the future.  
Fuel cells are similar to batteries in how they store chemical energy in the form of hydrogen and oxidant [20]. The fuel cell will continue to produce power until fuel and oxidant are supplied, thus behaving like a factory. The capacity of the fuel cell depends upon the fuel tank size. Therefore fuel cell power rating may vary from a few kW to MW [21]. Surplus energy from renewable energy sources during fewer peak hours can be used for the electrolysis of water, producing hydrogen. This hydrogen can later be used in the fuel cell to produce electricity during peak hours or for electricity breakdown [22]. This paper will describe, through several experiments, the operation of fuel cells and calculate the energy efficiency for series and parallel connected fuel cells on the portable educational prototype. In addition, it also describes the principle of operation of electrolyzers, which is used to the splitting of water molecules into hydrogen and oxygen [23,24].  
The rest of this paper is organized as follows: Section 2 presents the theoretical background of the fuel cell. Section 3 illustrates the portable kit's setup and the experiments' details. Sections 4 and 5 present the experimental results of the prototype and the conclusions, respectively.