2.7 kWp solar system with 300 L Fothermo boiler for hot water production

The Offgridtec 2.7 kW solar system with a 300-liter Fothermo boiler (MPN 018920) offers a comprehensive solution for your hot water supply. The system includes 6 bifacial solar modules from Luxen Solar, each with an output of 450 Wp, as well as all the necessary cables to ensure a smooth installation. The photovoltaic floor-standing water heater features an integrated heat exchanger for providing hot water and can be seamlessly connected to existing heating systems.

You can use hot water at the sink, in the shower, or in the kitchen without needing to connect to the power grid. Thanks to the plug-and-play design, you can install the solar system yourself in just a few simple steps.

Components of the Offgridtec 2.7 kW solar system with 300-liter Fothermo boiler

• 6x Luxen Solar 450W Bifacial TopCon N5 Full Black solar modules
• 1x Fothermo 300-liter photovoltaic water heater
• 3x Offgridtec 2-way Y-connectors, including extension cables (pair)
• 6x Offgridtec 10-meter 6-mm² MC-4 connection cables (plug/socket extension)

Fothermo 300-Liter Photovoltaic Water Heater - Hot Water System

The Fothermo 300L water boiler uses solar energy to provide cost-effective hot water. With three independently operating photovoltaic heating elements, it delivers hot water quickly and reliably. The 3 MPP trackers and DC heating elements provide a photovoltaic heating output of up to 1,800W.

Flexible inlet and outlet connections allow for customized installation, including the option to connect a circulation line. The water heater comes equipped with pressure relief and check valves. The freestanding water heater can utilize up to a total of 6,000 Wp of photovoltaic power. An existing heating system can be connected directly to the heat exchangers integrated into the water heater to ensure a sufficient supply of hot water even on days with little sunlight.

Technical Specifications for the Fothermo 300-liter Water Boiler

• Volume: 300 liters
• Max. heat loss: 50.2 W
• Nominal pressure: 0.8 MPa
• Dimensions: 1,605 x 670 x 760 mm
• Weight: 88 kg
• 3 MPP trackers

Heat exchanger

• Rated pressure: 1 MPa
• Max. temperature of the heating fluid: 110°C
• Max. temperature in the tank heated by the heat exchanger: 95°C
• Surface area: 1.12 m²
• Volume: 5.4 liters
• Continuous output according to DIN 4708: 35 kW
• Flow rate according to DIN 4708: 14 L/min
• Output according to EN 12897: 19.3 kW
• Heating time according to EN 12897: 39.4 min
• Pressure drop: 50 mbar

Photovoltaic heating

• Max. current draw: 16 A
• Rated electrical power: 1,800 W
• Max. connected power: 6,000 Wp
• Max. connected power per MPPT: 2000 Wp
• Max. water temperature: 65°C
• Max. open-circuit voltage: 50 V

Supplementary Heating

The water heater can be supplemented in various ways when solar radiation is insufficient. One option is to use an existing wood pellet, gas, or oil heating system, which is connected via the water heater’s integrated heat exchanger. A temperature sensor in the boiler controls the supplementary heating. Alternatively, an electric heating element with a 6/4-inch thread can be installed. The maximum water temperature is 65°C, and a heated 300-liter boiler can supply approximately 675 liters of water at 34°C.

The Luxen Solar 450W Full Black Bifacial Solar Module

The bifacial 450W Full Black solar module from Luxen Solar’s Luxneri N5 series (MPN LNDX-450ND) sets new standards in solar technology. It combines innovative technologies such as LECO N-TOPCon cell technology and a 96-cell half-cut layout to maximize efficiency. It also utilizes SMBB half-cut cell technology, which helps optimize performance.

• LECO N-TOPCon Cell Technology
• SMBB Half-Cut Cell Technology
• Low BOS & LCOE
• Bifacial cell module technology
• Excellent anti-PID and low LID performance
• 3 bypass diodes - minimized power loss during shading

Technical Specifications

• Maximum power: 450W
• Module voltage (Vmp): 30.08 V
• Max. current (Imp): 14.96 A
• Open-circuit voltage (Voc): 35.21 V
• Short-circuit current (Isc): 16.02 A
• Module efficiency: 22.52%
• Max. operating voltage: 1,500 V DC
• Operating temperature range: -40°C to +85°C
• Dimensions: 1,762 x 1,134 x 30 mm
• Cells: 96 (6x16)
• IP68 protection rating
• Connection: MC4
• Weight: 24 kg