The Cost of Renewable Power: A Survey of Recent Estimates - Green Energy and Efficiency: An Economic Perspective - page 252

transportation costs make the system uneconomical. One important distinction is
whether they come from waste materials of some type or from dedicated cultivated
crops. The wastes used come mainly from three sources: agriculture, forestry and
municipal solid waste. Being waste, they are available at little or no cost. The cost
of dedicated crops is much higher, and the cost of oil must be singled out, since it is
required to cultivate the crop itself and to transport it. This takes up resources that
might otherwise be used in food production, which may further complicate this
option. Accordingly, capital costs may have an impact on the

nal cost that ranges

from 50 90 %, depending on the cost of the feedstock. The remaining

costs are for O&M, which again may range from 5 to 20 % according to Irena [ 19 ].
Table 2 presents some data on capital costs for the main technologies that have
reached maturity. For stoker-boiler combustion, which is the most common by far,
the

60 to 80

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gure may be as low as USD 660/kW in developing countries with a high of
1,860, though this may re ect lower emission standards as well as other local costs,

so the gure must be taken with care. In OECD countries standard values can be in

the range of USD 1,880 - 4,260/kW. The costs of CHP technology are appreciably

higher, but the difference must be weighted against the combined generation

capacity of heat and power, so the nal LCOE is not necessarily higher. The

equipment required to add co- ring ability to existing systems is much less

expensive, costing in the range of USD 140 850/kW, which may be especially

signicant for extending the dispatchability of CSP solar plants. The LCOE can be
as low as USD 0.02/kWh on good sites, with a high of 0.06 (Table 1 ). These

-

gures

make the technology competitive in most situations. More typical gures lie in the

range of USD 0.06 0.15/kWh, but systems may still be competitive depending on

the local alternatives.
Combustion ef

-

ciency is generally in the range of 25 35 %, and capacity factors

-

are usually high (80 90 %), provided feedstocks are available at all times, partic-

ularly all year round, which may not always be the case for agricultural and other
wastes. One aspect of this technology that has not been suf

-

ciently discussed to

date is its dispatchability. This may become more signi cant in a future context of

mass deployment of other intermittent renewable power sources (solar and wind).
The two operating modes noted in the case of hydropower are available, i.e. con-
tinuous mode and peak demand load, and this also has an impact on the LCOE.
Dispatchability is based on combustion technologies, so it may be more similar to
the red plants than for hydro power. However such plants may still

be quite relevant in the context of mass deployment of renewables, especially at
local level. Capacity factors may also depend on the mode in which the system is
operated, almost exactly as occurs with hydro power, i.e. continuous mode or peak
load. In the latter mode capacity factors are lower, but

gure for gas

nal LCOE may
improve. Indeed, the very concept of LCOE is less applicable in these circum-
stances, as noted in the discussion of other dispatchable technologies, particularly
hydro power and CSP with TES.
Given the low energy density of most types of feedstock, transport costs may
have a strong impact on total cost. This means that the size of the combustion plant
should be at most moderate, since the geographical radius of the collecting area

the