Ice protection panel system

A method, comprising:

• forming a lower shell and an upper shell of a panel, wherein:
• the lower shell comprises a lower wall and a lower peripheral sidewall extending upward from the lower wall, the lower wall and the lower peripheral sidewall together defining a lower interior cavity;
• the upper shell comprises an upper wall and an upper peripheral sidewall extending downward from the upper wall, the upper wall and the upper peripheral sidewall together defining an upper interior cavity, wherein, when the lower shell and the upper shell are assembled together:
• the lower peripheral sidewall and the upper peripheral sidewall together define a perimeter sidewall of the panel that extends between the lower wall and the upper wall, and
• the upper and lower interior cavities are in communication with each other such that they together form an interior space of the panel, with the interior space being defined within the lower wall, the upper wall, and the perimeter sidewall;
• and
• the panel further comprises:
• complementary locking structures arranged on opposite sides of the perimeter sidewall;
• and
• a lower alignment structure extends upward from the lower wall and an upper alignment structure extending downward from the upper wall, the upper and lower alignment structures being complementary with each other to facilitate alignment of the upper and lower shells;
• and
• joining the lower shell and the upper shell together;
• and
• injecting an insulation material within the interior space.