Potential application of vacuum insulated tubing for deep borehole heat exchangers

Polish energy sector is heavily dependent on coal resulting in large CO2 emission per capita. The country has considerable potential for geothermal energy development, as there are large numbers of deep and abandoned wells that might be utilized for geothermal heat production. Following paper investigates potential reconstruction of abandoned or negative wells into deep coaxial borehole heat exchangers. Main focus was put on selection of coaxial inner column which enables for heat carrier circulation. To maximize the heat uptake from geothermal systems based on borehole heat exchangers, it is advised to use inner column made from material with lowest possible thermal conductivity coefficient. Vacuum Insulated Tubing, as one of the options of insulated inner column, can significantly improve heat production and increase efficient energy use. This technology found plethora of applications in offshore and onshore petroleum industry and is yet to gain more popularity within geothermal sector.