Geothermal heat utilization system and geothermal heat utilization method

A geothermal heat utilization system comprising:

• a pair of wells;
• a pipe having two ends which are immersed in stored water of both of the wells so as to connect the pair of wells to each other;
• a pair of pumps which are provided in the respective wells and pump up the stored water through the pipe;
• valves each of which is provided on a pressurization side of one of the pumps in one of the pair of wells;
• and
• a heat exchanger which is configured to exchange heat with the pipe, wherein
• at least one of the valves includes a water injection valve configured such that water in the pipe is injected into the well, the water injection valve being immersed in stored water of the well,
• the geothermal heat utilization system further comprises a lid in an opening in an upper portion of at least one well out of the wells, and
• the lid limits contact of the stored water with air to limit the generation of particles due to oxidation of the stored water.