As part of the Investment Decisions project the team undertook a systematic review of the literature on electricity generation levelised unit cost estimates (hereafter referred to as unit costs).

The principal aims of this paper are to examine the range of reported unit costs for major generating technologies, show the range of estimates, explain where possible the reasons for the range, and show to what extent there is any clustering around central values. In addition, the paper explains the components of unit cost calculations and discussed what is, and is not, included in these calculations.