Solar Energy Perspectives - IEA

Chapter 5: Industry and transport
and many others (Figure 5.5). Good efficiency in collecting heat requires slightly more
sophisticated collectors, such as advanced flat-plates or evacuated tubes possibly
complemented with small CPC devices (see Chapter 7). Recent improvements in the
technology of stationary collectors suggest that the cost-effectiveness could be roughly
similar in a 50°C to 160°C temperature range, as greater investment costs will also lead to
greater fuel savings.
Figure 5.5 Process heat in selected sectors, by temperature levels
160-400 o C
100-160 o C
60-100 o
C
Below 60 o C
100
90
80
70
60
50
40
30
20
10
0
%
1.5 EJ 4.5 EJ 2.6 EJ 6.4 EJ 2.3 EJ
Transport
equipment
Machinery
Mining and
quarrying
Food and
tobacco
Textile
and leather
Source: Taibi, Gielen and Bazilian, 2010.
Key point
Food, beverage, textile and transport industries need mostly low to medium-temperature heat.
Many industrial parks are located outside cities and surrounded by flat agricultural land. It
could be possible to reconvert some limited agricultural lands to an energy use. Waste lands
and brown fields (contaminated sites) offer even more preferable options.
High-temperature process heat is different. In areas with good DNI, solar heat can be
provided at any temperature level, with concentrating solar systems (see Chapter 7), use of
which has been suggested for many industrial processes, from forming processes to thermal
treatment of crude oil. Parabolic troughs have been the most widely used devices for
industrial process heat below 400°C, mostly for food or textile industries. For example, the
Frito-Lay factory in Modesto, California, uses 5 065 m 2 of parabolic troughs on 1.5 ha to
deliver pressurised water at 250°C. The steam generated heats the oil used to fry potato and
corn chips. In India, a few laundries are being equipped with several Scheffler dishes, hooked
up with existing boilers, to provide steam for washing and cleaning. In Egypt, a pharmaceutical
company some time ago installed parabolic troughs to produce the bulk of its process heat.
Another example is pottery firing with the solar oven of Mont-Louis (France) with Moroccan
potters (Chapter 7), which substitute for hardly sustainable biomass. There are about 30 000
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