A panelboard supplies electricity to multiple loads, such as lighting fixtures and/or other electrical devices via one or more high-amperage circuit breakers and one or more low-amperage circuit breakers. The panelboard includes one or more vertical busbars and one or more horizontal busbars coupled together in a single housing. The one or more horizontal busbars are coupled to a main input breaker that receives electricity from a source. The main input breaker distributes the electricity to the horizontal busbars. The horizontal busbars distribute the electricity to the high-amperage circuit breakers coupled thereto and to the vertical busbars. The vertical busbars distribute the electricity to the low-amperage circuit breakers coupled thereto.