One of the most remarkable advantages of SOFCs and DCFCs is their ability to co-generate high level heat greater than 600 \({}^{\circ}\)C if involved in end-use applications [8; 10; 11; 18; 19]. Table 1 gives the comparison of different fuel cells (based on electrolyte type) in terms of their operating temperature, power, efficiency and applications [20]. During the last decade, lot of research has been done on fuel cell systems but it will take many years to mature due to technological hurdles which are being encountered. Enhancing durability and lowering the cost are two prime challenges for the commercialization of fuel cell. The fuel \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Fuel Cell** & \
\begin{tabular}{c} **Operating** \\ **Temperature** (\({}^{\circ}\)**C**) \\ \end{tabular} & **Power (kW)** &
\begin{tabular}{c} **Efficiency** \\ **(\%)** \\ \end{tabular} & **Application** \\ \hline PEM (Polymer & 60–110 & 0.01–250 & 40\%–55\% & Portable, Mobile, Low power generation. \\ AFC (Alkaline Fuel Cell) & 70–130 & 0.1–50 & 50\%–70\% & Mobile, space, military. \\ PAFC (Phosphoric Acid & 175–210 & 50–1000 & 40\%–45\% & Medium to large scale power generation and CHP \\ Fuel Cell) & & & (Combined Heat and Power). \\ MCFC (Molten & 550–650 & 200–100,000 & 50\%–60\% & Large scale power generation. \\ Carbonate Fuel Cell) & & & Vehicle auxiliary power units, medium to large scale power generation and CHP, off-grid power and micro CHP. \\ SOFC (Solid Oxide Fuel & 500–1000 & 0.5–2000 & 40\%–72\% & Mobile, portable. \\ Cell) & & & & Vehicle auxiliary power units, medium to large scale power generation and CHP, off-grid power and micro CHP. \\ DMFC (Direct Methanol & & & & power and micro CHP. \\ Fuel Cell) & 70–130 & 0.001–100 & 40\% & Mobile, portable. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of different types of Fuel Cells. cell technology must be cost competitive and better than other conventional power technologies available today. Also, as per the department of energy USA, the most challenging task for cost effective commercialization of fuel cell is the production of hydrogen. The challenge related to the production of hydrogen is the requirement of energy needed for its production. The task is to use or develop alternative sources that do not need electricity to produce hydrogen. Different processes have been explored in order to reduce the cost of hydrogen production [1; 21]. The safe transportation of hydrogen is another issue on which researchers are working [1; 22]. SOFCs works on gaseous fuels mostly like H\({}_{2}\) and CO. As a fuel, the DCFC uses solid carbon and gives high efficiency providing the prominent advantage of high electric efficiency (>65%-70%) and produces a pure stream of CO\({}_{2}\) without any extra cost of energy loss [6; 10; 12; 18; 19]. Solid oxide fuel cell is based on solid electrolyte sandwiched between two electrodes. SOFC has received more and more attention in recent years due to its better efficiency and durability. The SOFC is considered very flexible among other fuel cells in terms of fuels which is a significant advantage over the other fuel cells. In the current review, the technical and commercial status of high temperature solid oxide fuel cell is discussed. Current research in SOFC is focused on identification and synthesis of innovative materials that can reduce the manufacturing cost and enhance the lifetime of SOFC. Reduced cost and bulk production of the SOFC will make it competitive with currently available conventional power technologies [12; 18; 21; 23; 24; 25; 26; 27; 28; 29].