fully loaded. This occurs because the industrial customer requires process cooling even during periods of low air conditioning demand. The process load is tied to industrial production rather than outdoor temperature.” Andersson, on the other hand, cites reduced requirements for new power stations, transmission and distribution stations for electricity as additional energy-efficient benefits. “With the conventional approach, there would have to be so many power plants with their distribution network so large that it’s almost non-feasible.” TECHNICAL CHALLENGES Though there are significant benefits that district energy brings with it, it is not without its share of technical challenges, when district cooling facilities have to be designed in the Middle East. “Because the combination of high temperature and humidity here is enormous, condenser cooling is our biggest technical challenge,” says Todd Sivertsson, General Manager, FVB Energy, Bahrain. In simple terms, chillers have a cold and
Bernt Andersson
Khalil Issa
warm side, similar to a refrigerator. The condenser, located on the backside of the refrigerator, needs to be cooled down. “If you try to use air to cool the condenser for large chillers,” explains Sivertsson, “this would require vast heat transfer areas, and there’s not the space. So, instead, we use water to cool it down, which is also much more energy efficient.” Since the Ministry of Works does not permit using municipality water for cooling – and rightly so – sea water is used. Herein lies a challenge: “Sea water is very corrosive,” Sivertsson continues, “so you need good materials or you must produce fresh water from the sea water.
Regardless, your plant must be located near the sea. It’s cost-prohibitive to have long intake and outfall pipes to the sea.” A second challenge is Bahrain’s high groundwater table with its corrosive, brackish water. Underground pipe connections, therefore, must be one hundred percent watertight. With constrained power supplies, more
Mark Spurr
Todd Sivertsson
district cooling plants need to construct electrical substations into their facility, which adds a level of complexity. Factor in the limited, but valuable, Bahrain real estate, and you now have stakeholders interested in integrating district cooling into building projects, such as with Bahrain Financial Harbour. District cooling development is totally intertwined with the pace of real estate development. Says Spurr: “To the extent that you have major real estate developments occurring in hot climates, there is going to be a very good correlation with the growth of district cooling.”
ECONOMIC CHALLENGES The district cooling industry, in general, requires extensive capital at the outset. A payback timeframe is easily 10 or more years, making it difficult to entice investors. Investors want a quick return on their investment, and that is not possible with district cooling. The economic challenge, then, is
Dominic McPolin
to build cost-effective facilities in the context of a rapidly changing and uncertain infrastructure. But how do you lay a pipe across a road when the road hasn’t been built yet, or it is planned for future expansion? Issa – as do others – feels the industry is currently undergoing reassessment. “The next few years will see a more careful consideration focusing on modularity and scalability,” he says. “Gone are the mega plants concept – a web of plants interconnected and closely associated with loads, impacting infrastructure costs.” A Gulf-specific challenge Summer 2010 | CHILL
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