Page 264 - Geothermal Energy Renewable Energy and The Environment

254 Geothermal Energy: Renewable Energy and the Environment

Levelized cost (cents/kWh)
0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0

Wind-class 5
Geothermal-dual flash
Geothermal-binary

Coal-IGCC
Conventional combustion cycle
Hydro-small scale
Advanced nuclear
Biomass-IGCC
Biomass-fluidized bed boiler

Solar-parabolic trough
Solar-photovoltaic
Ocean wave

FIGUre 13.2 Levelized costs for publicly owned utilities for various conversion technologies for the state
of California in 2007. Also shown is the range of rates customers paid for electric power (gray band). (Data
are from Klein, J. and Rednam. A., Comparative Costs of California Central Station Electricity Generation
Technologies. California Energy Commission Report CEC-200-2007-011, 2007.)
100.0
Geothermal-binary
Geothermal-dual flash
Biomass-fluidized bed boiler
80.0 Biomass-IGCC
Advanced nuclear
Coal-IGCC
Capacity factor (%) 60.0 Hydro-small scale

Wind-class 5
40.0
Solar-parabolic trough
Solar-photovoltaic
Ocean wave
20.0

0.0
0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0
Levelized cost (cents/kWh)

FIGUre 13.3 Comparison of capacity factor (plotted as a percentage) and levelized cost (in cents/kWh) for
the same suite of conversion technologies as represented in Figures 13.1 and 13.2.

As noted above, levelized cost is subject to a variety of influences that reflect both market condi-
tions and the performance of the technology. Research and development efforts that impact the effi-
ciency of the conversion technology or that impact the cost of generation will change the levelized
costs. Although predicting specific research and development outcomes is impossible, it has proven
informative to use retrospective analyses of the evolution of various technologies to forecast future