A Breath of Fresh Air
District Cooling is fast gaining market share in the Middle East.
Mention Dubai to anyone and it immediately conjures images of the BurjKhalifa and the Burj Al Arab, iconic landmarks that reflect the stratospheric ambition of this tiny emirate.
Dubai may have become synonymous with structures that stretch high into the sky, but a visit to the historic creek-side neighbourhood of Bastakiya reveals a rather different side of its character.
A number of charming old buildings have been preserved, a startling reminder of how far Dubai has come in such a short space of time. Not only that but some modern developments, such as the Madinat Jumeirah hotel and leisure complex, have adopted this traditional style.
Probably the most standout feature of these buildings is the distinctive wind towers that protrude from the top. These curious cubic structures are open at the side, designed to capture any precious breeze and direct it downwards into the room below.
This was an early, rudimentary attempt at airconditioning to provide some light relief from the extreme temperatures that afflict the Gulf for around half the year. Today, it is unthinkable for residents to live without chilled air in their homes, offices, cars and public transport.
Fast growing Gulf states such as the UAE, Qatar and Saudi Arabia, tend to think big when it comes to property developments, whether they be residential, commercial or a mix of both. It is in this context that district cooling (DC), the centralised provision of chilled air rather than conventional air conditioning (AC), has been rising to prominence in parts of the Middle East.
Large developments such as Jumeirah Beach Residence and Business Bay in Dubai, Al Maryah Island and Mohammed Bin Zayed City in Abu Dhabi, and the Pearl in Doha, Qatar, all use district cooling.
As George Berbari, CEO of DC Pro Engineering, explains: “In general, a District Cooling System is the preferred air conditioning system for buildings or facilities that have a large-scale cooling energy demand. As the main alternative to conventional AC systems, district cooling has huge growth potential in Arab countries where its real estate sector is still in its early stages but is considered one of the most dynamic.”
In the Gulf Cooperation Council (GCC), cooling demand exceeds around 45 million refrigeration tons (RT), with district cooling contributing just six percent (6%) of that. In Dubai that rises to more than 20% and demand is expected to increase by 5% to 7% per year while supply will increase by 20%, or around 500,000 RT, annually.
Compared to traditional AC, district cooling systems reduce power consumption by around 50%, Berbari says. When used in conjunction with thermal storage it can also reduce peak power demand by 60%. Clearly this is a huge advantage in a region where more than half of all the electricity generated is used for cooling purposes.
Plants with electric chillers are currently the dominant ones used with just 25% of district cooling plants incorporating thermal storage and treated sewage effluent as make up for the cooling tower. However, more and more newer plants are now required to use these technologies thanks to governments gradually introducing regulations.
In addition, tri-generation - or combined cooling, heating and power generation (CCHP) - where exhaust and jacket heat recovery can be used with absorption chillers in series with electric chillers and thermal storage - could provide a major reduction in primary energy sources.
On the surface then, it would seem that district cooling is the obvious choice for large scale developments in the Middle East. However, the industry is not without its challenges.
In fact Berbari says that district cooling in the region has reached a point where it is in danger of stagnation as the technology is advancing at a much slower rate than other heating, ventilation and air conditioning (HVAC) applications.
“The district cooling industry continues to apply a 10-year-old technology with the only advancement coming from chiller manufacturers improving their efficiency. Meanwhile, newer HVAC systems pose additional threats to district cooling as air cooled chillers and air cooled ducted split continue to enjoy popularity with a 70% market share.”
That view is echoed by Hassan Younes, technical director and partner at consulting firm Griffin.
“The use of thermal storage and new, more efficient chillers are improving plant efficiencies but at a very slow pace,” he says. “If district cooling is to be used extensively, geothermal heat, cogeneration or tri-generation should be explored to increase the plant’s total efficiency.”
Another technology that has recently been making inroads into the Middle East could eventually provide a shot in the arm for the district cooling market.
“The way forward is by synchronising district cooling tri-generation with renewable energy sources,”Berbari says. “This can result in 75% savings in primary energy as compared to electric powered district cooling.”
A further challenge is the vast quantity of water required for the district cooling process, whereby chilled water is used to cool air. In such a water scarce region, the source of that water can be a major contributing factor to the cost of the district cooling process. Treated Sewage Effluent (TSE), for example, is seven times cheaper than desalinated water in Dubai, Hassan says. However there is not always enough TSE available for district cooling purposes, especially during the hottest months of the year when water demand - for everythingfrom cooling to irrigation - skyrockets.
“Currently, district cooling in the emirate of Abu Dhabi operates on approximately 100% fresh water as TSE is not yet available in the capital but is planned to be available soon,”Berbari says.“In Dubai around 30% of district cooling plants use TSE and many existing plants are converting from fresh water to TSE water.
“Qatar and Saudi Arabia have now mandated that all district cooling plants use treated water. Within the next two to three years, TSE or non-desalinated water will be the main source of water in the district cooling industry and will roughly be covering at least 70% of all district cooling plants in the GCC region.”
A costly solution?
It’s understandable that governments encourage the use of a cooling solution that can save on energy as, for the most part, electricity in the Middle East is provided by state-owned utilities and the cost to the end user is usually subsidised by the government. However, there is still the question of whether district cooling is the cheapest cooling solution for the end user.
“It is a general concession in the market that district cooling bills are always higher than conventional cooling methods,” says Hassan Younes. “This harms a potentially very good opportunity provided by district cooling systems to maximise energy efficiency in cities.”
In addition to this there is a lack of clarity in the billing systems used which are not regulated, Hassan says. As a result there is little knowledge among the end users when it comes to the capacity and demand charges.
When done correctly district cooling can be the most cost effective as well as the most energy efficient cooling solution for the Gulf, Hassan says. However the reality can be quite different as some projects don’t deliver the level of efficiency they promised while providers don’t always offer reasonable pricing.
Efficiency must improve
Optimisation of the delivered cooling load is clearly an issue in some cases. Maged Makar, Business Development Director at Stellar Energy, a company that has installed 300,000 RT of district cooling in the MENA region, says: “The industry has suffered from over investment in large (sometimes oversized) plants and big networks that have not yet seen the benefits due to slowed down connections.
“District cooling companies that have adopted a modular, phased approach have been more shielded due to the planned phased investment and simplicity of relocation.
“We see more modular and decentralised cooling plants being adopted due to the the phased investment and lower running costs. These are smaller plants distributed across the development, but connected and operated as if they were one.”
Inefficiently designed systems can contribute to high charges for end users. As a result, some private developers have shied away from district cooling and are opting to build their own mini-DC schemes rather than go with a local provider, Makar says. However, many developers don’t even have that option.
The Kingdom of Saudi Arabia and Qatar are beginning to catch up and some are predicting that district cooling in these markets may overtake the UAE due to the impressive pipeline of projects, says Makar. But despite the rapid growth, the market in the Middle East could be reaching a fork in the road.
“If the market does not align with end user expectations, I think that district cooling will struggle to attract new customers,” Makar says. “On a positive note, the developed DC markets are currently facing government regulation to achieve higher efficiency levels on both power and water front -reducing peak power consumption and higher operational power efficiencies by utilising thermal energy storage tanks & Treated Sewage Effluent for the makeup water required.”