; (2) estimates the amounts the eligible entity will save on fuel and maintenance costs due to the covered loan; and (3) provides reasonable assurance that the eligible entity will make all payments on the covered loan. (b) Link to low or no emission bus and bus facilities grant applications The Secretary shall establish a procedure under which an eligible entity that submits an application under section 5339(c) of title 49, United States Code, for a grant relating to a low or no emission bus or bus facility may amend the application and be considered for a covered loan under this Act without having to submit a separate application under this section. (c) Guidance and best practices Not later than 1 year after the date of enactment of this Act, the Secretary of Energy, in consultation with the Secretary of Transportation, shall develop and publish on the website of the Department of Energy guidance on best practices for transit districts to enter into innovative relationships with public utilities and bus manufacturers to incorporate into operations and financing of electric buses and infrastructure— (1) secondary use of the battery; (2) vehicle-to-grid integration; (3) charging infrastructure cost shares; or (4) battery performance guarantees. 6. Terms and conditions (a) In general A covered loan— (1) shall not accrue interest