; or (ii) be open to the public. (B) Public hydrogen fueling station developers and operators An eligible entity described in subsection (b)(2)(E) that receives a grant under the program to be used only for the use described in paragraph (1)(B) shall make each applicable hydrogen fueling station described in that paragraph open to the public. (4) Capital costs of vehicles With respect to the capital costs described in paragraph (2)(A)(i), the amount of grant funds used for those capital costs shall not exceed, with respect to each heavy-duty fuel cell vehicle purchased by the eligible entity and used for the applicable project, the lesser of— (A) an amount equal to the difference between— (i) the cost of the heavy-duty fuel cell vehicle; and (ii) the product obtained by multiplying— (I) the cost of a comparable gasoline- or diesel-fueled vehicle; and (II) 0.5; and (B) $500,000. (e) Amount of a grant The amount of a grant provided by the Secretary under the program shall be not more than $20,000,000. (f) Cost sharing The non-Federal share of the cost of a project carried out using a grant under the program shall be not less than 20 percent. (g) Leak detection Each eligible entity that receives a grant under the program shall conduct— (1) a hydrogen leakage monitoring, reporting, and verification (also known as MRV ) program; and (2) a hydrogen leak detection and repair (also known as LDAR ) program. (h) Reporting (1) In general An eligible entity that receives a grant under the program shall submit to the Secretary such operational data relating to eligible costs described in subsection (d)(2) as the Secretary, in consultation with the Secretary of Energy, may require to accelerate market deployment of heavy-duty fuel cell vehicles that use hydrogen as a fuel source. (2) Requirement The operational data required by the Secretary under paragraph (1) shall include, at a minimum, data relating to— (A) operational expenses; (B) fuel use