Renewable Energy in Industrial Applications – an ... - Unido

RENEWABLE ENERGY IN INDUSTRIAL APPLICATIONS
One of the largest solar cooling systems is installed in Sudan. It provides cooling to a hospital, the
Salam Centre for Cardiac Surgery, run by the NGO Emergency under critical operating conditions as
described in the Box below.
Every hour, the Salam Centre requires 28 000 m 3 of cold air.
This has been achieved by a system employing 288 vacuum-sealed solar collectors with a total
surface of 900 m 2 . These produce 3 600 kWh with zero CO2 emissions, an amount of energy that
would otherwise require the burning 335 kg of gasoline per hour. Each solar collector houses
copper tubing lodged inside vacuum-chambered glass tubes through which water circulates,
allowing the sun to heat the water by irradiation without heat dispersion. The water running
through the pipes constitutes the vector fluid transferring heat to a 50 m 3 reservoir, where water
is stored at a temperature around 90°C. The transformation of heat into cooling power takes
place in two absorption chillers, where the circulating hot water heats up a solution of Lithium
bromide. By reaching the gaseous state, Lithium bromide removes heat and water cools down to
7°C. This cold water is then circulated in the Air Treatment Units (ATU), cooling air to the desired
temperatures. From the 8 ATU installed in the Centre, air is then further filtered by F7, F9 or
absolute filters, according to the needs of the different areas of the Centre. When solar energy is
insufficient to meet the Centre's cooling requirements, two gasoline boilers switch on
automatically, re-adjusting the water temperature in the reservoir, ensuring an optimal
functioning of the chillers.
Another example is the use of solar heat for the dairy industry. Various designs have been
demonstrated. One of them is the so-called ARUN concentrator (Kedare et al., 2008).
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