As coal-fired power plants age, they lose efficiency. Much of this loss in efficiency is due to mechanical wear on a variety of components resulting in heat losses, as can be seen in Figure 6. Lower power plant efficiency results in more CO2 being emitted per unit of electricity generated. The mode of operation (i.e., base load26 vs. cyclical) also has a large effect on efficiency and fuel use. The options most often considered for increasing the efficiency of CFPPs include equipment refurbishment, plant upgrades, and improved O&M schedules. Cost of the improvements is often compared to the expected return in increased efficiency as a primary determinant of whether to go forward with a program