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chapter on magnetic
eld sources and the chapter on prototypes for more infor-
mation about the devices).
The authors of that study emphasized that all the calculations were run on non-
optimized geometries, as well as that some information about the structures was
lacking, and therefore the results did not necessarily re
fl
ect the potential of the
original design of a particular device.
In 2014 another economic evaluation was made by Tura and Rowe for a con-
centric Halbach cylinder [
48
]. In the study the authors took into consideration the
costs of the magnetocaloric regenerator to be 150 US$kg
−
1
, and the cost of the
Nd
B magnets to be 42 US$kg
−
1
. Their
rst estimation was based on an
analysis of the operating characteristics of their nested (double) Halbach structure,
for which they found that the cost at a 2 Hz frequency of operation ranged from a
minimum 10 US$W
−
1
to a maximum of 21 US$W
−
1
for a zero temperature span
and it grows exponentially as the temperature span approaches the maximum and
the cooling power goes to 0 W. The authors were then further searching for the
optimized parameters of the geometry, utilization and frequency in order to mini-
mize the operating and capital costs. The resulting costs of the magnets varied from
100 to 800 US$ and the costs of the AMR varied from 50 to 400 US$ for the
cooling powers from 100 to 400 W. Finally, the optimized costs of cooling (US
$(Wcooling)
−
1
) varied from 0.6 to 1.05 US$(Wcooling)
−
1
for the COP from 2 to
4.5, respectively, and for cooling powers in the range from 0 to 400 W.
In most of the analyses shown in this chapter the authors have shown the
economic potential of magnetocaloric energy conversion. As can be seen, this will
strongly depend on the costs of permanent magnets, and then the costs of the
magnetocaloric material, which both represent high cost fraction of the device, e.g.
60
Fe
-
-
80 %. Furthermore, the frequency of operation is the parameter that will for a
certain temperature span between the heat source and heat sink as well as the
desired ef
-
ciency, de
ne the power of the magnetocaloric device and related spe-
ci
c cost. This, however, mostly depends on the ef
ciency of the heat transfer
between the working
fl
uid and the magnetocaloric material.
9.4 A Note on Economic Analyses for Magnetocaloric
Energy Conversion
As can be seen from the review of existing economic analyses a large number of
these analyses do not consider all the costs that are present in the capital costs of the
magnetocaloric device. The correct economic evaluation must consider mass pro-
duction and the following costs:
Manufacturing costs of the permanent-magnet assembly (material costs, labour
costs, manufacturing costs);
Manufacturing costs of the magnetocaloric regenerator and its housing (material
costs, manufacturing costs);
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