Italian solar module manufacturer Sunerg Solar Srl has developed a 1,500 W water heater solution that can be powered simultaneously by a solar panel and grid electricity.

The company offers the Frog Photovoltaic Water Heater with its own solar module, a maximum power point tracking (MPPT) controller, and an 80 L water boiler with two resistances, of which one is activated by the photovoltaic panel.

“All the electricity generated by the module is injected into the water heater through the FROG V10 controller,” a company spokesperson told pv magazine. “It can work with a photovoltaic module with a power output of up to 450 W, a maximum short-circuit current of 50 V and a short-circuit current of 9.0 A.”

The controller is based on a Perturb and Observe algorithm, which consists of an artificial neural network that reduces the oscillations at the MPP. “It maintains the point of maximum energy transfer from the panel to the water heater following the variations in the lighting conditions of the panel,” the spokesperson further explained. “Moreover, a complete scan of the panel is periodically carried out to avoid the so-called ‘false maximum points' due to uneven illumination of the module itself.”

The FROG 10 controller is encased in a die-cast aluminum container equipped with perforated flanges for deployment onto a wall and cables with connectors for the solar panel. It also includes a plug connector with fixing screws for connecting the resistance and temperature sensor from the boiler to the control unit. “Once the connector has been inserted into the control unit, it practically turns it on,” the spokesperson added.

The boiler measures 45 cm x 75 cm and weighs 22 kg. It is sold by the manufacturer in combination with its own solar modules, preferably with its X Max XL panel with a power output of 320 W to 340 W and efficiency ranging from 19.18% to 20.38%. The panel weighs 18.3 kg and features busbar cell technology. It also has an IP67 enclosure and the maximum system voltage is 1,000 V. Its temperature coefficient is -0.36% per degree Celsius and its operational temperature ranges from -40 C to 85 C.

According to the manufacturer, the solar panel can generate approximately 2,800 Wh per day and the heater is able to raise water temperature from 20 C to 50 C. The daily thermal energy supplied to the resistance is approximately 2.410 kCal.

“We offer the whole package for €1,200 ($1,29o) excluding VAT and installation costs,” the spokesperson explained. “It comes with a three-year warranty for the water heater and a two-year warranty for the FROG 10 controller.” For the panel, Sunerg offers a 25-year product warranty and a 30-year performance warranty.