This report explores the costs of new electric energy storage technologies to utilities in the United States for commercial operation in 2026 or 2027. Lithium iron phosphate (LFP) lithium ion, sodium ion, nickel-hydrogen , and iron-air battery energy storage system technology types are included in 10 MW and 100 MW sizes. LFP, sodium ion, and nickel-hydrogen battery energy storage systems (BESS) are included at 4 hrs of usable duration and iron-air is included at 100 hrs. Methods for scaling the base design cost results based on changes to system design (power capacity and energy capacity), tariffs, and materials costs are included as well.