When applying for an energy rebate, costs can vary depending on the specific program and your circumstances. Generally, there are no application fees, but some rebates might require you to provide supporting documents, which could incur costs if you need to obtain them from professionals. Additionally, you might need to consider any ongoing costs associated with energy efficiency upgrades if the rebate is tied to such improvements. It’s best to check the specific program details on the official government website or contact the relevant provider for information tailored to your situation.