; and (iv) to establish loan terms, if applicable, that maximize the benefit to the low-income households, and households in disadvantaged communities, receiving solar energy from the eligible entity; (B) require the Secretary to rescind any amounts provided to the eligible entity that are not used during the 2-year period beginning on the date on which the amounts are initially distributed to the eligible entity, except in any case in which the eligible entity has demonstrated to the satisfaction of the Secretary that a longer period, not to exceed 3 years after the date of initial distribution, is necessary to deliver proposed services; (C) with respect to a loan provided under this section, establish— (i) an interest rate equal to the cost of funds to the Department of the Treasury for obligations of comparable maturity to the loan as of the date on which the loan agreement is entered into; and (ii) a payout time that maximizes the savings to customers during the effective period of the agreement; and (D) contain such other terms as the Secretary may require to ensure compliance with the requirements of this section. (e) Use An eligible entity shall use a loan or grant provided under this section for the purpose of developing new photovoltaic solar projects in the United States for low-income households, households in disadvantaged communities, and individuals who otherwise would likely be unable to afford or purchase photovoltaic solar systems through 1 or more of the following activities: (1) Photovoltaic solar equipment and installation To pay the costs of— (A) solar equipment, including only photovoltaic solar equipment and storage and all hardware or software components relating to safely producing, monitoring, and connecting the system to the electric grid or onsite storage