SOLAR VAULT: Solar Heat Storage and Electric Conversion Device

This study aims to develop Solar Vault, a three-part hybrid system designed for solar heat collection, storage, and electrical conversion in off-grid coastal communities. Inspired by the EuroDish CSP system, Solar Vault uses a parabolic dish mirror to focus sunlight onto a sand battery, which stores heat for conversion into electricity via SP1848-27145 SA thermoelectric generators. Designed for accessibility, it is a fully manual, DIY system built from readily available materials. This study utilizes an applied research design, including a developmental research design and a descriptive quantitative research design. The developmental research design enables researchers to design, develop, test, and refine Solar Vault to assess its full capabilities and limitations. The descriptive research design allows the researchers to analyze the results of the data by calculating using the formulas and then presenting them in graphical form to determine the characteristics of the relationship between the variables. Results show that the system maintained a cold-side temperature of 21°C, while the hot side exceeded 100°C, creating an 80°C temperature difference, which is a notable improvement in thermal efficiency over prior studies. Electrical performance testing revealed a peak power output of 1.86W (6.40V, 0.29A) and an average of 1.07W (3.91V, 0.23A) over 30 minutes, outperforming previous research. Efficiency analysis showed a maximum of 6.41% at 1.52W, surpassing prior systems' 4.80% peak efficiency at 0.09W. However, the sand battery exhibited poor heat retention, stabilizing at 30°C after 300 minutes, significantly underperforming compared to existing thermal storage methods. Load testing demonstrated that Solar Vault could power small devices, such as a 3V LED, DC electric motor, and 12V ducted fan, though it suffered from voltage drops averaging 43.09%, indicating inefficiencies in voltage regulation. While the device was unable to achieve its target output of 12V, 1A, it successfully generated usable power. The study concludes that Solar Vault is a viable thermoelectric generator for off-grid use but requires improvements in heat storage and electrical efficiency. Recommendations include exploring alternative thermal storage designs, optimizing voltage regulation, improving parabolic mirror design, and conducting further tests in optimal weather conditions.