Del. Code Ann. tit. 29, § 6939
(b) Prior to initiating a request for procurement of any product, an agency shall review the specifications for such product to determine whether an Energy Star product is available. If an Energy Star product is available, the agency is required to include in its bid specifications the requirement that the product be an Energy Star product unless the agency can demonstrate, in writing, to the satisfaction of the agency head, that a product with an Energy Star rating meets at least 1 of the following criteria:
The agency may include non-Energy Star rated equipment as an alternate in the bid documents to enable lifecycle costing analysis to be performed as part of the analysis of responsive bids. The agency shall be required to award a contract that includes the procurement of Energy Star rated equipment unless the agency can demonstrate, in writing, to the satisfaction of the Director, that the interests of the state would be better served by procuring non-Energy Star rated equipment.