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Masdar City: Testing Times

Masdar City gives insight into a sustainable future

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The plant is run by Abu Dhabi-based Environmena, an Abu Dhabi-based company, and has been online since June 2009. It features a 50:50 mix of 87,777 po
The plant is run by Abu Dhabi-based Environmena, an Abu Dhabi-based company, and has been online since June 2009. It features a 50:50 mix of 87,777 po
The two solar thermal collector systems have been in successful test operation already for more than three months.
The two solar thermal collector systems have been in successful test operation already for more than three months.
The brown, curved design of the residences is designed to reduce heat gain and provide shading, while the louvres on the metallic facade opposite both
The brown, curved design of the residences is designed to reduce heat gain and provide shading, while the louvres on the metallic facade opposite both

Masdar City has revised its timeline for the completion of its eco-city on the outskirts of Abu Dhabi. Utilities Middle East explored the site in October, gaining insight into the preparations for a sustainable future.

There are few ecological projects that match the ambition of Masdar City, the carbon-neutral development emerging from the desert sands of Abu Dhabi, and skeptics felt vindicated by the announcement earlier this year that parent company Masdar and architect firm Foster & Partners were reconsidering the master plan for the city..

While the new master plan, revealed in October, does indeed allow for a more gradualist approach, it also does little to contradict Masdar CEO Sultan Al Jaber’s claim that “the vision remains the same.”

Completion of Phase I, the development of one million square metres, has been pushed back by two years to 2015. The final build out of the entire six square kilometre complex is now expected between 2020 and 2025.

Masdar top brass explain this new timeline with the need to adjust to market demand. “We’re not going to build ahead of the market, we’re going to build to market demand,” says Alan Frost, Masdar’s director.

The Personal Rapid Transport (PRT) system, a fleet of remote-controlled, electric-powered pods, will not be the sole means of transport in the future city, and the roll out of the programme will depend on the speed of the city’s growth.

In addition, Masdar has abandoned the idea of generating all the electricity needed for the city within its confines, and will procure power from external renewable sources, which will nevertheless be owned by the cleantech company.

“In the short term, we will rely more on external plants, which will also be built by Masdar, such as Shams I,” says Afshin Afshari, manager of the Energy Management Department at Masdar City, referring to the 100MW concentrated solar power (CSP) plant that the Mubadala-owned company is constructing with Total and Abengoa. Shams I was announced in July, and will be operational by the second half of 2012.

Nevertheless, the company has not lowered its green targets, which is to create a carbon neutral, zero-waste city, Al Jaber said at press conference announcing the Shams I project.

“Masdar City is an important component of Masdar. While the review is very much required, the vision remains the same, and we won’t scale back or scale down.”

“The aspiration and the vision hasn’t changed, but it’s going to take us some time to get to where we want to get to. We’ve learned a lot along the way, we’ve learned that we were very bold in our aspirations, but we’re not giving up on the vision,” Frost said after the new master plan had been made public.

But this vision might not be achievable in the short term, and thus for Phase I of the city. “We may not be able to achieve all the objectives in the first phase of the city, although we will probably achieve operational carbon neutrality considering onsite and offsite renewable energy,” says Afshari.

Green MIST
While the timeline for the completion of the city has been extended, one flagship development has been completed to schedule. The Masdar Institute for Science and Technologies (MIST) in September opened its doors to the first batch of
students.

The institute gives an insight into the ways the future city will pursue sustainability, and a wander through the complex is illuminating. The campus, which consists of a main building, a knowledge centre and student quarters, will use around 51 percent less energy than average buildings in the UAE, and 54 percent less water.

Savings will be achieved by a host of energy efficiency measures and architectural design features. Around 30 percent of the complex’s energy use will be covered by solar panels on the roof, with 75 percent of hot water also being heated by
the sun.

“The courtyard is a good representation of what the master plan is in terms of how the space could be designed and in terms of trying to create this micro-climate where people can walk around rather than needing to use a car,” says Jürgen Happ, associate partner at Foster & Partners.

“You can feel the difference between where you came in at the site office and here. At the site office the perceived temperature is higher than it is here. We just tested this a week ago with a thermo camera. It is true that the heat difference is significant, over 20 degrees from downtown Abu Dhabi.”

He explains that unlike Abu Dhabi, Masdar uses smaller spaces, wind corridors and light-coloured flooring to reduce heat gain, a significant departure from the black asphalt and the wide boulevards of downtown. The air temperature may be the same, but the perceived temperature is far lower. This effect has been enhanced by the futuristic wind tower, which stands in the centre of the courtyard.

“The wind tower catches the prevailing wind from multiple directions and leads the wind down onto this space. Inside is a misting system basically pushing the air down, and that will be done in certain periods when people are actually gathering here. This is a modern version of the traditional Gulf wind tower, and we are trying to enhance the public realm, not just the interiors of houses,” he said.

Both the futuristic facade of the labs and the more traditional facades of the residences are highly energy efficient, Happ explains.

The brown, curved design of the residences is designed to reduce heat gain and provide shading, while the louvres on the metallic facade opposite both reflects and traps energy from the sun.

To not let used water go to waste, Masdar has built a wastewater recycling plant, capable of processing 1,500 cubic metres of water per day. The membrane bioreactor (MBR) plant will enable the reuse of water for irrigation purposes, and is sufficiently large to process almost 10 percent of the entire city’s sewage, says Afshari.

Solar options
While the energy needs of the city will not be covered by sources within the development itself, the institute already draws its power from a 10MW photovoltaic (PV) solar power plant situated only a few hundred yards away.

The plant, which is spread over 22 hectars, is currently only producing two to three MW, but even this modest amount presently exceeds the needs of the institute, so that the surplus energy is fed into the Abu Dhabi grid.

“At the moment, we are giving the government the extra electricity for free, as the feed-in tariff has not been worked out yet,” says Afshari.

Abu Dhabi will be first in the region to implement a feed-in tariff, a form of subsidy for renewable energy based on actual production costs, which are higher than for conventional energy.

The plant is run by Environmena, an Abu Dhabi-based company, and has been online since June 2009. It features a 50:50 mix of 87 777 polycrystalline and thin film modules from suppliers Suntech and First Solar.

The use of different technologies is no accident, and reflects Masdar’s interest in using current projects for determining the best technologies. While the jury is often still out, one thing is clear: “Crystalline panels are more expensive and more productive, while thin film modules are cheaper but less productive,” explains Afshari.

The panels are cleaned every two weeks without the use of water, to avoid waste and the growing of shrubs, which could impair the performance of the solar panels. This is a labour intensive process, and recently an automated cleansing system has been added to one row of panels.

The power plant does not exhaust Masdar’s experimentation with PV. The company also has a test field with panels from 40 different suppliers, whose performance is being measured with results being relayed to the producers.

“We don’t try and develop PV that is more suitable for region, it’s a very difficult process. We can only give indications to vendors which one works best, and they can go and improve their products,” says Afshari. The performance of PV panels is impaired by the sun and the dust, an important consideration in a region where panels can be heated up to around 75 degrees.

Concentrated energy
Photovoltaic is not the only solar technology researched on site. The institute also erected a concentrated solar power plant, used by lecturers and students to gain insight into how the technology functions in the hot desert terrain.

The project, run in conjunction with the Tokyo Institute of Technology, is unique, believes Dr. Matteo Chiesa, assistant professor at the Institute. “We are operating the power plant by ourselves, and this is a unique experience, there is no other university that has this kind of facility.”

The main challenge that needs to be overcome is to concentrate the solar energy, he says: “Solar is not easy to concentrate, but the advantage of the power plant is that you can play and do whatever you want.”

As with photovoltaic panels, the conditions for CSP in the region are not as optimal it would appear at first glance.

“In the UAE, everyone says there is a huge amount of radiation, which is true. But it is not a useable radiation for this kind of concentrated technology. What you can concentrate is what comes directly from the sun. And that direct component is not super great.”

Research efforts have to be directed at designing technologies that collect radiation in a slightly different way than technologies in use in other parts of the world.

“All the different technologies that you buy from abroad are based on the ideal situation. Here the situation is slightly different, so you could design a technology to take that into account. You cannot expect the Spaniards or the Americans to come here and solve it when we don’t yet know ourselves what the condition in the UAE is.”

Solar thermal cooling
One other feature in Masdar City’s solar array is its solar thermal cooling system, a regional first.

Masdar has successfully activated a proprietary double-effect solar thermal cooling system – the first in the Gulf region, and one of only a handful in the world - to test the viability of using the sun’s heat to cool buildings in the future city.

The pilot plant is the only one in the world to combine two different concentrating solar thermal collector technologies in a single system. ‘Green’ air-con systems generally consist of conventional compression chillers powered by electricity from PV panels or concentrated solar power (CSP) plants.

While such conventional chillers and air-conditioners use electricity to run a compressor, a double-effect absorption chiller such as the one being tested at Masdar City uses heat to activate a chemical process that provides chilled water for cooling.

If successful, the technology could become a major source of cooling across the city. Solar cooling is ideal for medium-scale cooling loads, such as those of supermarkets and shopping malls, and can also be implemented in a central cooling plant configuration, such as for district cooling.

It is especially well-suited to address peak cooling demand as the solar thermal energy supply closely matches high daytime cooling demand. Its optimal cooling temperature is at 24 degrees, two degrees warmer than the standard temperature in shopping malls, but far lower than outside summer temperatures.

The collectors include a Sopogy parabolic trough collector with uniaxial tracking and a total mirror aperture area of 334 m2. It heats thermal oil, whose heat is transferred to the system’s pressurised water circuit through a heat exchanger.

A Mirroxx linear Fresnel collector with uniaxial tracking and a total mirror aperture area of 132 m2 heats the pressurised water directly.

Schneider Electric provided the control system components for the pilot plant and EM Hidromontaza installed the integrated system. The Fraunhofer Institute of Solar Energy will analyse the monitored data and assess system performance.

“The two solar thermal collector systems have been in successful test operation already for more than three months,” explains Simon Bräuniger, project manager for Masdar’s pilot plants.

“The collector’s thermal energy has been driving the Broad 50 TR double-effect absorption chiller that is cooling our office building since mid-September, marking the start of full operation for the pilot project.”

The system provides sustainable cooling to 1 700 m2 of office space using advanced air-con and delivery equipment from Swegon, such as active chilled beams and an air-handling unit that achieves 75 percent energy recovery.

The objective is to demonstrate that high-temperature solar thermal cooling is more cost-effective and requires a smaller collector footprint compared to a conventional electric chiller plant powered by solar-generated electricity.

The solar cooling pilot installation produces cooling equivalent to about 80 conventional split-type air-conditioning systems, leading to annual emissions reductions of about 70 000 kg of carbon dioxide.

The pilot plant will be operated for about two years to test the technology’s suitability in Abu Dhabi’s climate and weather conditions, and assess the scope of cleaning and maintenance requirements.

Digging deep
Masdar are literally digging deep in their quest to explore further sustainable ways of thermal cooling. The cleantech company has built a geothermal plant near MIST, which consists of two 2.5 kilometre deep wells drilled into the ground.

The wells reach down to an aquifer, a layer of water stored in permeable rock. From this water, thermal heat is extracted, which can be used to generate power.

In the case of Masdar’s plant, this energy amounts to five to 10MW, says Afshari. To make use of the plant, Masdar is considering building a district cooling plant on top of the wells.

The plant would be able to generate between 1500-3000 tones of cooling on a continuous basis, an advantage it has over solar power.

“The advantage of geothermal is that it’s a steady resource compared to solar, in that even at night you have the same capacity as you have during the day. If you manage a resource intelligently, it can last forever,” says Afshari.

The heat that originates from the wells would be converted by absorption chillers in a thermo-chemical process, he adds.

If the plant is a success, the concept could be applied elsewhere in the UAE, says Afshari. “Before you start drilling, you never know what you will find, but this could actually be quite promising, as the aquifer we have discovered is actually quite extensive, we think it is below the entire UAE and beyond.”

As with every aspect of the great Masdar experiment, great opportunities seem only a few innovations away.

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