43 C.F.R. § 2806.50
If you hold a right-of-way authorizing solar energy site-specific or project-area testing, or solar energy development, you must pay an annual rent and fee in accordance with this section and subpart. Your solar energy right-of-way authorization will either be a grant (if issued under subpart 2804) or a lease (if issued under subpart 2809). Rents and fees for either type of authorization consist of an acreage rent that must be paid prior to issuance of the authorization and a phased-in MW capacity fee. Both the acreage rent and the phased-in MW capacity fee are charged and calculated consistent with § 2806.11 and prorated consistent with § 2806.12(a) . The MW capacity fee will vary depending on the size and technology of the solar energy development project.
43 C.F.R. §2806.50