Dynamic auctions are beneficial for purchasing related items like energy products or environmental allowances. These auctions involve bids specifying quantities of each item, such as megawatt-hours of electricity or tons of emissions. The goal is to efficiently procure goods from the lowest-cost suppliers while minimizing payment. The approach considers the buyer's objectives and bidding environment to design effective auctions. The key findings suggest that auction design should focus on achieving a balance between efficiency and cost minimization in realistic procurement scenarios.