Masdar to use the cooling power of the sun

New system goes on show before Future Energy summit.

ABU DHABI // Masdar, Abu Dhabi's clean energy company, is testing a new technology that uses the power of the sun to keep buildings cool.
The technology went on show yesterday on the eve of the World Future Energy Summit.
The conference, organised by Masdar, brings the world's experts in renewable energy to Abu Dhabi. Ban Ki-moon, the United Nations secretary-general, will address delegates today as the event opens at the Abu Dhabi National Exhibition Centre.
The summit will focus on renewable and future energy solutions, innovations, investments, policy and vision, and cover a range of themes including energy policy, investment and funding, green buildings, clean transport, solar and wind energy and biofuels.
The solar cooling project undergoing trials in Masdar City is one of several green technologies that the company hopes to employ at what will be the world's largest carbon-free development.
"There are only a handful of these systems in the world," said Simon Braeuniger, a project manager at Masdar.
The system, a first for the Gulf region, is built by the Masdar team from components provided by various equipment manufacturers, Mr Braeuniger said. Conventional technologies use photovoltaic panels to produce electricity from light, and then run traditional compression chillers to provide cooling. The new Masdar system uses two solar thermal collectors that gather energy from the sun to heat water to 180°C for the system's 50-tonne absorption chiller. After a chemical reaction, "on the other side of the process we are getting chilled water", Mr Braeuniger said.
This water, chilled to 7°C, is used to cool a 1,700 square metre building at Masdar's site offices.
"The technology of absorption chillers is quite well known, but not in this particular application," Mr Braeuniger said.
A decision on whether the technology is reliable will be reached when the system has been in operation for a year. "We need to get this plant operating throughout the summer season. This is the interesting time for us," Mr Braeuniger said.
Masdar also hopes to use hot water from deep underground for air-conditioning. Two wells have been drilled to a depth of 2.5km each. The water is not hot enough to generate electricity but will be enough for the absorption chillers, said Dr Afshin Afshari, manager of Masdar's energy management department. A test facility will be completed by the end of this year.
If the two trials are successful, solar cooling could greatly help Masdar in its aspiration to be carbon-neutral.
"Cooling is one of the major types of energy demand in the city," Mr Braeuniger said. In the UAE as a whole, cooling consumes between 60 and 70 per cent of the total energy demand of buildings.
Masdar City, which currently comprises the 43,000 square metre campus of the Masdar Institute of Science and Technology, is sending more energy to the Abu Dhabi electricity grid than it consumes. It has a 22-acre solar photovoltaic plant with a capacity of 10 megawatts, and solar photovoltaic panels on the roof of the institute building provide another megawatt.
"We can say right now that Masdar city is energy positive," said Dr Afshari. "Of course, this will change as new buildings come online in about a year or two."
Some of the buildings, such as the one housing Masdar headquarters, will add significantly to the city's energy production capacity. The headquarters building, for example, will have panels with a joint capacity of three megawatts, he said.
The economic climate has concentrated attention on energy efficiency. "We are more focused on demand-side measures than just putting solar panels everywhere," Dr Afshari said.
Architectural features of buildings, such as high-performance insulation and double-glazed windows, can significantly reduce energy demand, he said.
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