Renown is your reputation with the Council of the Conclave.  It functions as the "experience points" of Conclave.

Renown serves two purposes in Conclave: it determines character level advancement, and it also can be used to acquire better equipment at the Vault of Arms.

Renown accumulates at the rate of 100 Renown per completed quest, and each quest can only give Renown to a character the first time that character completes the quest. 

Players who contributed to the Kickstarter campaign at appropriate levels were granted the Honor known as Patron which grants their characters 100 extra Renown when they are created.