The potential energy-supply contributions from the options assessed in this report have been estimated technology by technology. The committee did not, however, conduct an integrated assessment of how these technologies might compete in the marketplace and how that competition and other external factors could affect actual deployment rates and outcomes over time. For example, the successful deployment of energy efficiency technologies could reduce the demand for electricity and the need to deploy additional electricity-generation capacity, except perhaps to correct regional supply imbalances or replace aging assets with more efficient and environmentally benign facilities. Also, the utilization of biomass for liquid fuels production could reduce the supplies of biomass available for electricity generation. Therefore the potential contributions of the energy-supply and end-use technologies identified in this report should not be viewed as predictions of any specific future mix of primary energy resources and conversion methods.

The committee has not made judgments about the relative desirability of the supply options described in this report or about their appropriate pace and scale of deployment. Such decisions are beyond the committee’s charge and are the responsibility of policy makers, investors, consumers, and, indeed, all citizens.

The committee and its panels developed the cost estimates presented in this report by using a range of methodologies (as described in Annex 3.A in Chapter 3 and in Part 2). It derived some of these estimates independently, with the assistance of consultants, whereas other estimates came from assessments documented in the literature. The cost estimates themselves were based on a number of underlying assumptions about commodity prices, construction costs, and fuel, regulatory, and operating costs, as well as on “conditional” assumptions¹⁶ about the success of new-technology deployment. As a consequence the cost estimates presented in this report should not be used to make detailed comparisons across technologies. However, because these estimates are presented as ranges that reflect the principal uncertainties in the underlying