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Twin perspectives on District Cooling

Jerome Sanchez spoke to Bob Miller, Technical Specialist for DC of Marafeq and to Ahmad Shehadeh, Chief Financial Officer and Acting CEO of Qatar Cool.

| | Apr 9, 2014 | 12:39 pm
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District Cooling was ushered into Qatar as the cooling option of the future. While the sector has coped with teething troubles, new challenges have emerged, mainly due to use of TSE being made mandatory. Jerome Sanchez spoke to Bob Miller, Technical Specialist for DC of Marafeq and to Ahmad Shehadeh, Chief Financial Officer and Acting CEO of Qatar Cool.

In your estimate, what is the size of the District Cooling industry in Qatar?

Marafeq Qatar – According to statistics developed by Kahramaa, the District Cooling market end of 2014 will be around 500,000 Tonnes of Refrigerants (TR). In Lusail City alone, we expect the market load will grow to 350,000 TR by 2022.

Qatar Cool – Currently, there are many District Cooling systems implemented around the capital city of Doha, with their total capacity being close to 320,000 TR. The application of the system in major developments proves that District Cooling is gaining popularity amongst developers. We should expect to continue to see a surge in the country’s District Cooling market due to its numerous benefits at all levels.

What are the drivers that encourage the growth of the District Cooling industry in Qatar?

Marafeq Qatar – The benefits driving the desire for District Cooling are:

  1. The capital expense for producing chilled water is transferred from the building developer to the end-user via the District Cooling provider’s tariff.
  2. District Cooling requires less capacity due to load diversity and reduced standby capacity. Individual buildings must design for the instantaneous peak (usually with a safety margin) and with standby production units for redundancy and reliability.
  3. Since production is centralised, utility networks for potable water, electricity, and sewer are less.
  4. Architects have greater creative freedom to design the building and grounds without being concerned about siting chillers and especially cooling towers.
  5. Greater efficiency means lower peak and annual power consumption, which translates into lower investment in generation, transmission and distribution facilities.
  6. In District Cooling, trained professionals maintain the equipment.
  7. District Cooling production equipment is more likely to maintain its level of efficiency than is expected for individual buildings.
  8. Lower power consumption means lower emissions of air pollutants for the full life cycle.
  9. Facility managers purchase a manufactured product (chilled water) rather than raw materials (chillers, structures, power, water, etc.) and produce their own product. Building owners can focus on their core business (real estate) rather than to venture into the utility business. Over the building life cycle, facility management costs will be lower compared to self-generation.
  10. Noise levels are greatly reduced compared to site-located outdoor units or air cooled condensers.

Qatar Cool – The country is seeing growth in its population, which currently sits at a little over two million, as well as its commercial and industrial markets. This growth, although contributing to the development of the country, has also led to an increase in demand for water, power and cooling.

Due to its energy efficiency, reduction in carbon emissions, ease of operation and maintenance, reduction in electric distribution, demands and environmental benefits, the continued implementation of district cooling systems in Qatar will play an influential role in the country’s vision towards a greener future through efficient and sustainable energy.

On the other hand, what are the challenges that blow headwinds to District Cooling in the Peninsula?

Marafeq Qatar – The greatest challenge is the resistance of end-users to the rightly perceived high cost of District Cooling. End-users compare raw costs of self-generation (electricity) to the manufactured cost of chilled water. So, from the start they fail to see the capital cost of self-generation which is built into the rent. The end-user typically does not see the cost of maintenance – it is also built into the rent – but the building owner does. Mini-splits are checked and components are replaced repeatedly when they fail, which is always at some inconvenience to the end-user. Operation and maintenance costs for District Cooling are typically in the tariff, so the end-user sees them every month. The Qatari government subsidises electric power and benefits from the huge power reduction offered by District Cooling. But those savings never make it to the consumer, which exasperates the perceived cost differential between District Cooling and self-generation.

Qatar Cool – District Cooling is at an all-time high in the peninsula. With the increase in developments and the need for sustainable solutions, District Cooling is an essential key factor in achieving Qatar’s objectives. As District Cooling is a major consumer of water, the challenge is to find technical solutions to use alternative sources for the cooling process. Continuous coordination is ongoing with the governmental authorities on this issue. Besides that, lack of awareness about District Cooling is a challenge. Qatar Cool is regularly developing awareness campaigns to developers, endusers and society. These campaigns are a tool to educate the local market on the benefits of District Cooling from all aspects.

As a District Cooling service provider, what innovative solutions have you employed to optimise total project life cycle cost?

Marafeq Qatar – What was considered innovative six years ago is now considered business-as-usual, but even business-as-usual approaches minimise lifecycle costs. Multiple plants connected through an integrated network with thermal energy storage (TES) allow equipment to be operated at their most efficient point. Operation and maintenance by professional staff means the plants are run efficiently for the full lifecycle. Using treated sewage effluent (TSE) reduces operating costs and all but eliminates consumption of potable water.

Starting with our first plant, Marafeq will use special-purpose software to optimise the entire plant operations and not just certain components. The software functions in a supervisory position over the plant control system and uses unique and patented algorithms to continuously adjust set points, pumps speeds, etc., to minimise power and water consumption.

Qatar Cool – If you mean the District Cooling plant by referring to the project, there are many technical innovative ways that our team has implemented to increase the efficiency of the plant. In addition to that, we work closely with our customers to enhance the delta T. We are, therefore, able to operate our plants below the system designed parameters, by providing one tonne of refrigeration below 1 KW of electricity.

Let us speak about TSE: What are the challenges and opportunities related to the use of TSE in District Cooling?

Marafeq Qatar – District Cooling providers all understand the need and benefits of using TSE and are agreeable to using it instead of potable water. The current challenges are quality, supply and environmental regulations.

The heat generated by the chiller compressors is rejected by evaporating water in the cooling towers. Since only pure water is evaporated, the minerals remain and become concentrated. Only so much water can be evaporated before some must be blown down and replaced with fresh, lower mineral content water. Although there are a number of parameters that we watch carefully, the simplest to understand is mineral content (commonly referred to as total dissolved solids) expressed in terms of parts per million (ppm).

For discussion, let’s assume potable water contains 300 ppm and cooling towers can operate up to 1,500 ppm, thus the water can be concentrated five times. The companies which provide TSE are unable or unwilling to guarantee quality suitable for replacing potable water in evaporative cooling towers, and in some cases, they cite 2,000 ppm, which means the minerals have to be removed before the water can be put into the cooling tower cycle. Hence, the need for reverse osmosis equipment.

In order to use TSE, distribution networks must be installed to reach District Cooling plants. As an aside, think how complicated this would be if individual buildings used water-cooled chillers and were mandated to or wanted to use TSE. Creating these networks costs money, and normally the costs would be recovered in the TSE delivered. If the TSE supplier at some point starts charging for the water, the cost won’t be zero, and the operating cost will increase. Until TSE networks are installed, it will be impossible for District Cooling providers to take advantage of this lower cost, recycled product.

Using reverse osmosis equipment to polish TSE sounds simple enough, but the downside is what to do with the water discharged from the reverse osmosis process. After all, the minerals removed are all in the reject water.

If the TSE enters at 2,000 ppm, the discharge will be maybe 3,000 ppm. And where can this water go? The sewage treatment plant (that recycles TSE) might not accept it, and the discharge limits to the sea is limited to 1,500 ppm. If TSE has 2,000 ppm dissolved solids, one would think TSE could not legally be discharged to the sea, and the situation becomes worse for the District Cooling provider with the additional concentration in the District Cooling plant.

In principle, the dissolved solids content should be similar to potable water, which makes up the primary source of what goes into the sewer: absent suspended matter. The source of the dissolved solids is alleged to come from infiltration of saline ground water into the underground sanitary (foul) water system. If this infiltration is the source of the problem, obviously correcting it would benefit those who use TSE. Otherwise, removing the suspended solids at the sewage treatment plant would be another solution, and in fact, this would appear to be the better approach. For all the reasons, central chilled water plants make sense (economy of scale, diversity, standby, centralised operation and maintenance), so too it makes sense for polishing TSE.

Qatar Cool – Qatar Cool’s plants are equipped to use TSE. We are currently working with the government (Asghal) to secure the sufficient quantity, to operate our plants. One of the major challenges is to have the TSE infrastructure available, and close to the plants. Using TSE presents an opportunity to reduce cost, as TSE is lower than potable water, which is currently in use.

Why the need to use TSE in cooling towers?

Marafeq Qatar – TSE is needed to comply with government regulations that require all District Cooling plants [in Qatar] to use it. In order to preserve precious desalinated water, providers have restricted the use of potable water as a conservation measure.

Qatar Cool – The TSE acts similar to potable water.

How does the use of TSE compare to other make-up water sources, cost-wise?

Marafeq Qatar – Currently, the commodity cost of TSE is zero as compared to potable water, whose tariff is QAR 4.4/m3. But the District Cooling operator is likely to experience additional costs. Since the TSE quality might not meet what is needed by the District Cooling plant, the operator may have to install reverse osmosis equipment, which adds to both the initial cost and the annual operating cost.

Qatar Cool – The amount of consumption of TSE is higher by about 40-50% than potable water. However, it is cost effective. Not only do you save money, but you are also helping save the environment, which is a major cause for Qatar Cool.

Could you tell us about your current customer profile? Which industries do your customers belong to?

Marafeq Qatar – Our current customer profile ranges from mixed use, residential, and commercial to railway stations and sporting facilities.

Qatar Cool – Qatar Cool’s customer profile consists of highend hotels, commercial, shopping complexes, ministries, residential buildings, villas and international restaurants, in the West Bay area and The Pearl Qatar.

Would you look to include more industries to your customer base?

Marafeq Qatar – Yes, as long as they can meet a certain profile, we are open to all industries

Qatar Cool – We are always open for new opportunities.

As a business, are you looking to expand beyond Qatar, or the Middle East? Which countries or regions are you looking at?

Marafeq Qatar – As a part of a global development company, Marafeq looks to expand as a utility company, wherever it can serve a need and develop a solid business model.

Qatar Cool – Qatar’s market has still not matured yet for us to consider expanding elsewhere. We believe that there are a lot of opportunities that exist now, and more to come soon with the country’s development plans.


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One comment on “Twin perspectives on District Cooling”

  1. mohamef says:

    What is the tds level of qatar water

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