Can You Use Solar Thermal Energy in Cold Climates?

System Design for Cold Climates

To optimize solar thermal energy systems in cold climates, it’s essential to use a well-insulated system and a high-efficiency collector. A typical collector efficiency of 60-70% in warm climates drops to 30-40% in cold climates. For instance, a system in Maine, USA with an average temperature of 32°F (0°C), would require a collector area 2-3 times larger than one in Arizona, USA with an average temperature of 75°F (24°C).

Radiant Floor Heating with Solar Thermal Energy

Radiant floor heating is an excellent application for solar thermal energy in cold climates. By circulating hot water through pipes embedded in the floor, it’s possible to maintain a comfortable indoor temperature even in extremely cold conditions. For example, a 1,000 sq. ft. home in Minnesota, USA with a well-insulated radiant floor heating system can maintain a 68°F (20°C) indoor temperature even when the outdoor temperature is -20°F (-29°C). This is achieved by circulating hot water at a temperature of 120°F (49°C) through the pipes, which is feasible with a well-designed solar thermal energy system.