The Blue Alloy Ingot is one of the most basic building blocks of Blutricity, which empowers most Tier 2 Technology in RedPower. Smelting your first Blue Alloy Ingot gives you the "Now In Blueberry!" achievement.
In an Alloy Furnace:
Currently the RedPower machines that need them are: Sorting Machine, Retriever, Blulectric Furnace, Blulectric Alloy Furnace, Solar Panel (RedPower), Accelerator, Battery Box, Blulectric Motor, Frame Motor, Thermopile, and Pump (RedPower).