This study analyzed the profitability and cost constraints of thin film solar PV modules for commercial sized lightweight roofs by using the reversed LCOE method. The focus will be on a particular technology of solar PV, namely, thin film solar PV module technology. Thin film solar PV modules are able to serve the niche market of commercial scale lightweight roofs, without competition with the highly matured traditional solar PV market. As such, the objective of this study is to derive actionable insights into the cost constraints of thin-film solar PV modules for these applications. Using the reversed LCOE method, figures show that there is a high variability in conditions that influences the performance and the profitability of thin film solar PV modules in a commercial scale lightweight roof project. This study shows that both profitable and unprofitable scenarios are possible and provides an analysis on how various conditions influence the project’s profitability.

To improve the efficiency of domestic heat energy use, a heat battery was added to a boiler. This heat battery contains a phase change material (PCM) characterized by low thermal conductivity and high specific heat, enabling efficient storage of residual heat energy. Paraffin wax was selected due to its high latent heat storage capacity; however, its low thermal conductivity posed challenges regarding storage time. To address this, a finned tube was introduced, and the feasibility of the heat battery for domestic applications was investigated. The effectiveness of the finned tube was evaluated using both a numerical model and an experiment. In the experiment, a temperature- and flow-adjustable water source was connected to a plain tube and a finned tube, with temperature and heat flux measurements recorded to assess the impact of the fin structure. These conditions were replicated in the numerical model for comparison. The results indicated that heat extraction from the PCM using the finned tube required approximately 60 minutes, compared to nearly five hours with the plain tube. These findings suggest that while the method shows promise, further development is needed before it is suitable for domestic implementation.