A water heating system includes a photovoltaic (PV) panel configured to generate a direct current from sunlight, a light sensor configured to measure a real-time radiation intensity of the sunlight, and a water chamber configured to receive water. A reconfigurable heating circuit including one or more resistive heaters and switches is configured to heat water in the water chamber. A controller is configured to receive the real-time radiation intensity from the light sensor and adjust the switches in real time to match a total resistance of the reconfigurable heating circuit with R.sub.Mppt in real time at least before the water boils. R.sub.Mppt is a characteristic resistance of the PV panel at a Maximum Power Point for the real-time radiation intensity.

A water heating system includes a photovoltaic (PV) panel configured to generate a direct current from sunlight, a light sensor configured to measure a real-time radiation intensity of the sunlight, and a water chamber configured to receive water. A reconfigurable heating circuit including one or more resistive heaters and switches is configured to heat water in the water chamber. A controller is configured to receive the real-time radiation intensity from the light sensor and adjust the switches in real time to match a total resistance of the reconfigurable heating circuit with R.sub.Mppt in real time at least before the water boils. R.sub.Mppt is a characteristic resistance of the PV panel at a Maximum Power Point for the real-time radiation intensity.