During firing I can see the red glow through the spaces between the kiln sections

There is little heat loss through a loose-fitting peephole plug or the cracks between kiln sections. This is because at 1100F / 593C and higher, the air molecules are spaced so far apart inside the kiln that heats no longer moves by convection. This is why you can hold a hand near an open peephole of a hot kiln without feeling heat pour out. One way to conserve energy is to make sure the lid lies flat against the kiln at high temperatures. If the lid rises half an inch at the front, the top section of the kiln will underfire. This could happen if the hinge binds. To conserve energy, fire dry greenware. Moisture in the clay will slow down the firing and waste electricity. If you must fire moisture greenware, leave the kiln at 200F / 93C until the moisture has dried out.