As the energy system continues to evolve and additional variable generation resources are deployed to meet carbon reduction targets, the need for firm capacity to fill the gaps when these resources are not available becomes increasingly critical to system reliability. Traditionally, peaking capacity has been served by low-capacity factor, natural gas fueled combustion turbine generation technologies. However, under a net-zero scenario, peaking technologies could be required to be low-carbon, zero-carbon, and/or be subject to CO2 emissions taxes. This study examines the cost of four different peaking technology options, various fuel options, and variables which could influence the cost of these technologies. Findings from the study indicate that future fuel prices and annual capacity factors of these peaking technologies would have a more significant impact on levelized cost of electricity, relative to technology capital costs.