The Cost of Renewable Power: A Survey of Recent Estimates - Green Energy and Efficiency: An Economic Perspective - page 239

precise monetary values to them. It is always worth starting with a clear, simple
measure such as the LCOE, provided that it is well understood, i.e. does not include
public support or externalities of any kind. If the policy maker wishes to include
externalities in the assessment, then all of them, positive and negative, should be
included.

3 Cost Per Technology

This section addresses the main focus of the chapter, i.e. costs per technology. The
technologies considered are CSP, solar PV, wind power, hydro power, biomass
power and geothermal, in that order. These technologies are selected because there
is suf

cient and reliable observed data on which to base some conclusions.
Their availability and cost at world level varies markedly, but they exist to some
extent everywhere, which justi es the universality of the approach. However, the

high level of availability of wind and solar sources has garnered public support,
resulting in a large-scale, increasing deployment which in turn has decreased costs
signi

' '

effect. These decreases
in costs, in turn, have helped increase deployments, so that a kind of

cantly because of the well known learning-by-doing

'

virtuous
circle ' has activated the implementation of these technologies even further. This
effect is not so marked for other technologies, though they may contribute in crucial
ways to joint deployment of renewables.
A brief technical description of each technology follows, together with a sum-
mary of its recent history, if any and an overview of its current situation and future
prospects based on the analysis above (not necessarily in that order). Speci

c costs
are presented and discussed at the end of the section in two condensed tables. Two
cost measures are discussed: the LCOE and total capital costs. Some observations
on Operation and Management costs (O&M) and fuel costs are also presented and
discussed where appropriate.

3.1 Solar CSP

CSP technology is based on the Direct Normal Irradiance (DNI) of the sun on the
surface of a heliostat (curved mirror), which concentrates sunlight either on linear
Parabolic Trough Collectors (PTC) or onto a point in a solar tower. The light is then
focused on a liquid that reaches a high temperature (400 C) and is then either

conducted to generate steam and power directly or stored in the form of heat in
another liquid suitable for that purpose (molten salts, usually), which is employed to
generate steam and power at a later convenient time (TES). Other less common
technologies are also available, such as the linear Fresnel collector and Stirling
dishes (see [ 17 , 20 ]). Some common, relevant aspects in all cases are that they
require large, fairly

- 600 °

at spaces to install the mirrors, and that considerable amounts