Light

Light works differently in Noih than it does in our world.

For one, it can be collected with specialised equipment and compressed into a liquid (Bykaas has one such machine). Artificial sources of light in Noih settlements are connected in turn to reservoirs of liquid light through pipework.

The light is also a source of heat. It warms up the land and, when in its liquid state, quickly evaporates if not contained. Even contained light slowly evaporates while heating the vessel it's in. The rate of this depends on the material's ability to insulate heat. Plants need light to grow, but this mechanism apparently isn't photosynthesis.