Fuel storage system and method for detecting residual quantity of fuel

A method comprising:

• measuring:
• a first temperature in a storage vessel accommodating fuel, wherein the fuel comprises a solid material and gaseous hydrogen, or
• a first internal pressure of the storage vessel;
• and
• predicting a first remaining amount of the fuel based on the first temperature and the first internal pressure and based on a relationship among different values of temperature, different values of equilibrium pressure, and different values of remaining amounts of the fuel measured at different times,
• wherein, according to the relationship, a remaining amount of the fuel is inversely proportional to temperature and is proportional to equilibrium pressure.

A fuel storage system comprising:

• a storage vessel configured to accommodate fuel, wherein the fuel comprises a solid material and gaseous hydrogen;
• a sensor for measuring a temperature or an internal pressure of the storage vessel;
• a processor;
• and
• a memory storing at least one instruction, wherein the at least one instruction, executed by the processor, is configured to:
• based on the temperature and the internal pressure and based on relationship data, predict a remaining amount of the fuel comprising at least a portion of the solid material and gaseous hydrogen, wherein, according to the relationship data, remaining amounts of fuel in the storage vessel and temperature have a negative correlation and remaining amounts of fuel and equilibrium pressure have a positive correlation.