On-Grid Flat Plate Solar Water Heater Collector Application for Electrical Energy Saving Contribution

Abstract

This study introduces a novel approach in Baghdad, Iraq, where flat plate solar heaters are directly connected to the electric heater without the use of storage tanks. This setup operates in a manner similar to solar cells connected to the electric grid, without the need for electrical energy storage during daylight hours (on-grid). A series of solar heaters, covering a total area of 3 m2, have been linked to the electric water heater. This arrangement allows the water supplied to the electric heater to either be pre-heated by the solar heaters or delivered directly. The percentage of electrical energy saved to obtain 100 liters of hot water at 40 °C using a water mixer was 53% and 57% when adjusting the electrical heater thermostat to 60 °C and 80 °C, respectively. This was found by comparing the electrical energy usage of the electric heater in both cases (preheating and direct supply).

Keywords

• Solar collector
• Electrical water heater
• Electrical energy saving
• Thermal batteries
• On-grid

References

1. [1] Aien, M., and Mahdavi, O., "On the way of policy making to reduce the reliance of fossil fuels: Case study of Iran", Sustainability 12(24): 10606, (2020).
2. [2] Perera, F., and Nadeau, K., "Climate change, fossil-fuel pollution, and children’s health", New England Journal of Medicine, 386(24): 2303-2314, (2022).
3. [3] Sharma, S., Agarwal, S., and Jain, A.," Significance of hydrogen as economic and environmentally friendly fuel", Energies, 14(21): 7389, (2021).‏
4. [4] Kalair, A., Abas, N., Saleem, M. S., Kalair, A. R., and Khan, N." Role of energy storage systems in energy transition from fossil fuels to renewables", Energy Storage, 3(1): e135,‏ (2021).
5. [5] Kumar, A., and Shobhna C., "Energy Requirement, Resources and Future Management: A Review", Indian Journal of Pure and Applied Physic (IJPAP), 59(11): 779-784, (2021).
6. [6] Khan, N., Kalair, E., Abas, N., Kalair, A. R., and Kalair, A., "Energy transition from molecules to atoms and photons", Engineering Science and Technology, an International Journal, 22(1): 185-214, (2019). ‏
7. [7] Ugwu, S. N., and Enweremadu, C. C., " Effects of pre-treatments and co-digestion on biogas production from Okra waste", Journal of Renewable and Sustainable Energy, 11(1), (2019).‏
8. [8] Qazi, A., Hussain, F., Rahim, N. A., Hardaker, G., Alghazzawi, D., Shaban, K., and Haruna, K., "Towards sustainable energy: a systematic review of renewable energy sources, technologies, and public opinions", IEEE access, 7: 63837-63851,‏ (2019).

9. [9] Buker, M. S., and Saffa B. R., "Solar assisted heat pump systems for low temperature water heating applications: A systematic review", Renewable and Sustainable Energy Reviews, 55: 399-413, (2016).
10. [10] Foteinis, S., "Wave energy converters in low energy seas: Current state and opportunities", Renewable and Sustainable Energy Reviews, 162: 112448, (2022).
11. [11] MacKay D.J., "Solar energy in the context of energy use, energy transportation and energy storage", Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 371: 20110431, (2013).
12. [12] Hassan, Q., "Evaluation and optimization of off-grid and on-grid photovoltaic power system for typical household electrification", Renewable Energy, 164: 375-390, (2021).
13. [13] Dagdougui, H., Ouammi, A., Robba, M., and Sacile, R., "Thermal analysis and performance optimization of a solar water heater flat plate collector: application to Tétouan (Morocco)", Renewable and Sustainable Energy Reviews, 15 (1): 630-638, (2011).
14. [14] Duffie, J. A., Beckman, W. A., and Blair, N., Solar Engineering of Thermal Processes, Photovoltaics and Wind, 5th ed., John Wiley and Sons, Inc., New Jersey, (2020).
15. [15] Anderson, B., Solar energy: fundamentals in building design, McGraw Hill Book Co., New York, (1977).
16. [16] Naghavi, M. S., Metselaar, H. S. C., Ang, B. C., Zamiri, G., Esmailzadeh, A., and Nasiri-Tabrizi, B., "A critical assessment on synergistic improvement in PCM based thermal batteries", Renewable and sustainable energy reviews, 135: 110259, (2021).
17. [17] Tabaei, H. and Ameri. M., "Improving the effectiveness of a photovoltaic water pumping system by using booster reflector and cooling array surface by a film of water", Iranian Journal of Science and Technology Transactions of Mechanical Engineering, 39(M1): 51-60, (2015).