A Solar PV-Based Inverter-Less Grid-Integrated Cooking Solution for Low-Cost Clean Cooking

Abstract

The cost of solar PV has been reduced to a level such that the levelized cost of solar electricity is either cheaper or competitive relative to the grid electricity. So, a low-cost integration of solar PV with grid can be a cost-effective solution for clean cooking. The usual technique of using grid-tied inverters contribute ~20% towards the energy cost. The proposed system incorporates a control circuit that connects grid electricity to the solar PV via a DC link and provides a DC output eliminating the requirement of grid-tied inverters. Most of the cooking utensils either have a resistive heating element or an electronic control circuit that is insensitive to input AC or DC and no modification is needed for the cooking utensils while using with DC voltage. In the proposed system, preference for power delivery is always given to the solar PV and the grid effectively operates as the backup for the system when solar PV output fluctuates due to varying weather and climatic conditions. As the absence of a grid-tied inverter in the system restricts the excess solar energy to be transferred to the grid, some kind of energy storage device is essential to run the system efficiently. A novel idea of storing solar PV energy in the form of hot water has been presented in this paper, with a cost-effective clean cooking concept. A simple and low-cost heat preservation technique has been suggested that requires a minimal change in habit for the users. Experimental results with multiple cooking utensils and foods have been presented and energy cost for cooking has been found to be as low as 4.75 USD/month, which is significantly lower (32%) than that of the grid-connected regular cooking system.