Is It Possible to Run a Propane Water Heater on Solar Power Alone?

Assessing System Demands

To determine if a solar-powered system can meet the demands of a propane tankless water heater, we need to calculate the appliance’s electrical power requirements. A typical propane tankless water heater draws 120-240 volts and 5-9 amps. For a 3.5-kW appliance, a 4-kW solar panel system with a 4-kWh battery bank would provide sufficient power for 4-6 hours of continuous operation. We must also consider the system’s efficiency, including the inverter, charge controller, and battery losses.

Designing the Solar Power System

A well-designed solar power system for a propane tankless water heater should include a battery bank to store excess energy generated during the day for use during periods of low sunlight or at night. A 48-volt deep-cycle battery bank with a minimum capacity of 300 Ah would be suitable for a 3.5-kW appliance. The solar panel array should be sized to recharge the battery bank within 4-6 hours of peak sunlight. A 4-kW solar panel system with a 2,000-W inverter and a 4-kWh battery bank would provide sufficient power for the appliance.

Safety Considerations and Venting

When powering a propane tankless water heater with solar power, we must ensure the system meets the appliance’s safety requirements. The system should include a gas detector to monitor propane levels and a ventilation system to prevent gas buildup. A 3-inch diameter venting system with a minimum 10-foot vertical rise would be sufficient for a 3.5-kW appliance. The system should also include a freeze protection system to prevent damage to the appliance and plumbing during cold temperatures. A 1/2-inch diameter freeze protection system with a 10-foot length would be suitable for a 3.5-kW appliance. The system should be designed and installed by a qualified electrician and plumber to ensure safety and efficiency.