Considering the declining trend of capital costs as discussed above, we analyzed the levelized costs of solar energy technologies when their capital costs drop by 5–25% from the present level.
Fig. 6 shows how the levelized cost of solar thermal trough, solar thermal tower, photovoltaic thin-film and photovoltaic crystalline would decline iftheir capital cost requirements were to fall by up to 25% and how those costs would compare to the maximum levelized costs oftraditional electricity generationplants.As illustrated inthe figure, the minimum values of levelized cost of any solar technologies, including tower type CSP, which is currently the least costly solar technology, would be higher than the maximum values of levelized costs of conventional technologies for power generation
(e.g., nuclear, coal IGCC, coal supercritical, hydro, gas CC) even if capital costs of solar energy technologies were reduced by 25%. Since fossil fuels such as coal and gas produce negative externalities at the local level (e.g., local air pollution) as well at the global level (e.g., GHG emissions), whereas solar energy technologies do not, it would be unfair to compare solar energy technologies with fossil fuel technologies without accounting for those externalities