Harnessing RenewableResources: the Masdar City plan

IntroductionThe Masdar City started in 2006 in Abu Dhabi, in the United Arab Emirates.

It is a planned city, which is being built by Masdar, a subsidiary of Mubadala Development Company, with the majority of seed capital provided by the government of Abu Dhabi.

The city is planned as one of the world’s first completely sustainable communities, combining renewable energy sources and efficient resource usage.

The city implements its zero carbon-footprint goal in two ways-

Producing energy by using only renewable resources. Reducing the energy consumption of the city by using

efficient technologies.

Generation of energyMasdar ‘s sources of energy include:

The 100-megawatt Shams 1 solar power plant.

A 10-megawatt solar photovoltaic plant.

Masdar City’s 1-megawatt solar rooftop installations.

A hydrogen power plant of 400 MW capacity that uses carbon capture method.

Solar energy Masdar City has an 87,000 panel solarfarm

called the Shams 1 solar Power station that lies beyond the city’s walls on 2.5 square kilometers of land with a capacity of 100 MWs.

Shams 1 is a Concentrated Solar Power(CSP) system that uses parabolic trough system technology.

Technology usedConcentrated Solar Power systems use mirrors or lenses to focus a large area of sunlight, or solar thermal energy, onto a small area. When the concentrated light is converted to heat, it drives a heat engine connected to an electrical power generator. The result is electricity.

A Parabolic Trough is a type of solar thermal collector that is straight in one dimension and curved as a parabola in the other two, lined with a polished metal mirror. A parabolic trough is made of a number of solar collector modules (SCM) fixed together to move as one solar collector assembly (SCA)

Shams 1

The Masdar City also has a small concentrating solar 100 kW demo site that uses the beam-down technology.

“The Beam Down Project” is a joint pilot project of the Masdar Institute, Japan’s Cosmo Oil Company and the Tokyo Institute of Technology

The Beam Down Technology

Thirty-three heliostats

circle the 66-foot tower in

three concentric

rings. Motors

adjust the elevation

and angle of the

heliostats throughout the day to

track the sun and direct

the reflected light toward

the underside of

the tower.

An array of 45 mirrors made to reflect as

much solar radiation as possible are arranged in concentric

circles,. When the reflected

sun from the heliostats

reaches the tower array, the mirrors redirect the light down toward the base of the

tower.

A ceramic receiver at the base of the tower absorbs

the radiation.

The radiation heats a

tank filled with molten salt, air, or water. The medium

then heats water to produce

steam and drive a turbine

Photovolatic cells The PV system located on the roof of the Masdar city buildings is

capable of producing 1 Mw of clean energy. Photovoltaic cells typically involves a semiconductor, such as

silicon, attached to an electrical circuit. When light hits the semiconductor it causes electrons, which are negatively charged particles, to flow, creating electricity in the circuit.

At a commercial scale, this process only harnesses 15 to 18 per cent of the Sun’s energy when using standard silicon-based photovoltaic (PV) cells. The efficiency is poor because the cells do not absorb infra-red light, which has a longer wavelength than visible light, and is inefficient at absorbing blue and green light, which occupies the shorter-wavelength end of the visible spectrum.

Dispersive Prismatic LensOther features include-• S

pecial antireflective glass which improves light absorption and reduces surface dust.

• It protects the module surface from humidity that could cause a loss in the module’s performance.

The IRENA headqurters in Masdar with the rooftop installation of PV cells

Carbon capturing Masdar has a special Carbon Capture ,use

and storage System (CCUS) that has the provision to capture 800,000 tons of carbon.

The CO2 feed stream from the Emirates Steel plant, containing 90% CO2 is transferred to a common compression and dehydration facility.

The feed stream is then compressed into dense phase; delivering a CO2 stream of over 98% purity, through 50km of the pipeline network, to be injected in an onshore field.

Enhanced oil recovery (EOR) is the implementation of various techniques for increasing the amount of crude oil that can be extracted from an oil field.

Gas injection is the most-commonly used approach in enhanced oil recovery with gases such as Natural gas, CO2, Nitrogen being the commonly injected gases.

The benefits of reinjecting carbon dioxide rather than natural gas include:

1) securing the long-term storage of the heat-trapping gas that contributes to climate change; and

2) preserving cleaner-burning natural gas so it can be used for power generation or as a transportation fuel.

Enhanced oil recovery through CO2 injection

Besides this, the HPAD(Hydrogen Plant Abu Dhabi) is a 60/40 joint venture between Masdar and BP which is the world’s first commercial-scale hydrogen-fuelled power plant utilising CCS. The hydrogen power plant will generate approximately 400 MW of low-carbon electricity, and could provide more than 5 per cent of all Abu Dhabi’s current power generation.

Transport There are no fossil fuelled cars in Masdar

City to contribute to the release of carbon dioxide.

Masdar collaborated with Mitsubishi Heavy Industries (MHI) to produce electric vehicles that are computer- driven and navigate a complex of tunnels under the concrete base.

These vehicles, called the personal rapid transit pods, or PRTs run on magnetic tracks using electric power.

Three flatbed Freight Rapid Transit (FRT) vehicles will play the role of trucks and vans to transport deliveries to and from the Masdar city.

The FRTs also will transport waste from the campus for sorting and reuse or recycling. 

Technology used

The vehicles are entirely powered by Lithium-Phosphate batteries.

The range of 60 kilometers on a 1.5 hour charge

In the PRT corridors, magnets have been embedded in the concrete floor every four meters to help the PRTs navigate, while an overhead antenna provides a wireless link between the PRTs and the system computer.

Underground PRT network

Cooling system The Masdar city has the world’s first proprietary double-

effect solar thermal cooling system and the only one to combine two different concentrating solar thermal collector technologies in a single system.

The Green air conditioning systems consists of conventional compression chillers powered by electricity from photovoltaic panels or concentrated solar power plants

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

Conventional chillers and air conditioners use electricity to run a compressor while a double-effect absorption chiller such as the one at Masdar City uses heat to activate a chemical process that provides chilled water for chilling.

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.

Solar Air Conditioning

Elevators To prove its 100% renewable target, the city of

Masdar uses regenerative elevators. A regenerative converter in an elevator is a

device that transmits power distributed by a traction elevator so that it can be reused by the building's power supply for other electrical systems.

They use less energy than non-regenerative drives, and reduce the excess heat in the building and are known to save upto 30% of the energy.

The permanent magnet motors in Masdar’s drives are capable of bidirectional energy flow

When power flows into the motor, it creates a lifting torque on the shaft and the carriage is lifted. When the carriage travels down, the motor acts as a generator, transforming mechanical power into

electrical power and pumping current back into the facility’s electrical grid to use elsewhere.

When a cab goes up with a light load and down with a heavy load, the system generates more power than it uses

Regenerative Elevators

Conclusion The Masdar project is supported by the known environmental

organizations like World Wide Fund for Nature and Greenpeace. On a per person basis, Masdar City uses less than half of the

water that an average city uses. This is achieved through the use of high efficiency appliances as well as smart meters that can detect leaks in water system. Additionally, 100% of the wastewater generated from the city is treated and reused in landscaping, which has led to huge water savings. Masdar City has also taken great efforts to manage its waste, with 96% of its construction waste reused in other ways to build the city. The Masdar city has certainly become a model for sustainable urban development regionally and globally, seeking to be a commercially viable development that delivers the highest quality living and working environment with the lowest possible ecological footprint.

references www.masdar.ae Gulfnews.com www.thefuturebuild.com en.wikipedia.org www.tradearabia.com www.mubadala.com Bullis K. “A Zero-Emissions City in the

Des- ert.” Technology Review 2009