# Techno-Economic Analysis of Waste Heat Recovery in Automotive Manufacturing Plants
## 2 Literature Review
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Authors, Year** & **Heat Sources** & **Experiment/ Modelling** & **Thermodynamic Analysis** & **Economic Analysis** & **The Technology of Waste Heat Recovery** \\ \hline [PERSON] and [PERSON], & Baking oven and & Modelling & Yes & Yes & Gas turbine and solar \\
2014 [9] & solar thermal & Modelling & Yes & Yes & thermal collector \\ [PERSON] et al., & 2018 [12] & RTO & Experiment & Yes & Yes & Direct use for other purposes \\ [PERSON] and & & & & & & \\ [PERSON], 2019 [10] & Air preparation room & Modelling & Yes & No & Heat pump and TES \\ [PERSON] et al., & & & & & \\
2021 [11] & Baking oven & Modelling & Yes & No & ORC and TES \\ [PERSON] et al., & RTO, compressors, & & & & \\
2022 [13] & and chilled water system & Modelling & Yes & Yes & TES and liquid desiccant \\ [PERSON] et al., & & & & & system configuration \\
2022 [14] & n.a. & Experiment & Yes & Yes & ORC \\ [PERSON] et al., & RTO and & Modelling & Yes & Yes & ORC, TES, solar \\
2024 [15] & solar thermal & Modelling & Yes & Yes & thermal collector \\ The state of the art in the presented study & RTO & Modelling & Yes & Yes & Carnot battery (ORC, heat \\ \hline \hline \end{tabular}
\end{table} 
Table 1: An overview of research progress on waste heat recovery in automotive painting shops. solution enables energy-efficient dehumidification and humidification processes, reducing the energy demand associated with conventional air management systems. The study showed that significant energy cost reductions were achieved by 44.4% in colder climates and 33.6% in hot and humid climates. Moreover, the PBP for implementing this technology ranges from 5.74 to 9.02 years, depending on the location and specific climate conditions. [PERSON] et al. [14] investigated the waste heat recovered to generate electricity by utilising an ORC. It is mentioned that while standalone ORC systems may not always be economically viable due to high investment costs and long PBPs, combining this system with cogeneration units can substantially reduce energy costs and achieve shorter PBPs, making the solution more attractive for energy-intensive industries like automotive manufacturing. In a recent article, [PERSON] et al. [15] proposed a waste heat recovery solution for automotive paint shops using a solar ORC system integrating solar energy with low-grade waste heat from RTOs. The proposed system uses waste heat to preheat the organic working fluid in the ORC, thereby improving overall system efficiency. In this study, the TES was also considered to store and accumulate the heat taken from solar sources. This study reported that the implementation of the proposed system could generate 712.2 kW of electricity, covering about 5.9% of the plant's energy needs while achieving an energy efficiency of 31.02%. Significant potential improvement in waste heat recovery in painting shops and automotive manufacturing plants remains. This article proposes an innovative system and presents the simulation results of a novel waste heat recovery system, which uses a heat pump to capture waste heat from the RTO. The recovered heat is stored in TES and later used to generate electricity through an ORC. This process is referred to as a Carnot battery system [16; 17]. In this case, the system offers an advantage for the double exploitation of the waste heat from RTO. In some regions with limited solar thermal energy collection, PV panels offer a promising alternative to power the heat pump. By installing PV panels on the factory roof, sufficient electricity can be generated to drive the system, making this an innovative and sustainable solution for waste heat recovery.