Masdar City: A Rising Star

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Artist's impression of Masdar's central Plaza.

Peter Hume examines plans for a zero-carbon, zero-waste, car free city in Abu Dhabi that will rely entirely on renewable energy sources, and asks whether the concept can become a sustainable reality......
 

Several attempts have been made to build sustainable cities. The Eden Project aimed to create a self-contained ecosystem; Dongtan and Huangbaiyu in China were both conceived as carbon-lean cities. These projects have all, to some extent, failed to meet their goals.

The Eden Project serves many worthwhile purposes - growing and preserving rare plant species, educating the public, demonstrating the principles behind maintaining a "spaceship Earth" - but it has not succeeded in being self-sufficient. Dongtan and Huangbaiyu have been criticised for failing to adhere to their own construction principles, being delayed, and running over budget.  

But a new star is rising in the east; the city of Masdar in the UAE. Backed by the oil-rich state, Masdar has a chance to succeed where others have failed. 

As a model for sustainability,  Masdar may not be relevant in many parts of the world, where funding is scarce, a cold climate creates different problems, or where space is not available for solar farms. What it can do, however, is demonstrate what can be done, and provide a medium upon which to refine our technology.   

What is Masdar?

Masdar is a 700 hectare development outside Abu Dhabi, with a projected population of 40,000, plus 50,000 commuters. Scheduled for completion in 2018, Masdar is designed to be carbon-neutral, powered by renewable energy, to require 60% less water per capita than neighbouring cities, to use significantly less energy per capita, and to recycle all its waste.

Masdar, the company, is an Abu Dhabi initiative to reduce the state's CO2, accelerate the development of renewable energy, and to secure long term income from international renewable energy projects.  Having profited immensely from oil, it seems only fair that Abu Dhabi should be willing to lead the way in renewables R&D.  

Masdar's books include a 20% stake in the 630MW London Array, the 6MW Seychelles Wind Farm, a 60% stake in SHAMS-1 (see below), Masdar City's own 10MW PV array, and a 40% stake in Torresol, a Spanish company developing concentrating solar power technology.  Not to mention Masdar City itself.  An impressive portfolio, although some would be uncomfortable if their landlord were also their energy, transport and water provider, and quite possibly their employer.  Cosy community or big brother-esque?

Ignoring any sociological issues, Masdar as originally planned is highly impressive. Unfortunately several ambitious initiatives, such as the city-wide PRT system, have fallen victim to the recession, but there is still much to celebrate...

Technology and Innovation

Masdar's designers imagined a city which uses a variety of renewable and energy saving technologies.  Some, such as photovoltaic panels and wind turbines, are not innovative in themselves, but the combined application of multiple technologies to meet the demands of an entire city is a world-first.  

Solar PV

Photovoltaic panels have been in use since the 1940’s, although today they are far more efficient.  

The original vision for Masdar was that the majority of its power would be generated by rooftop solar panels. Streetlights were to be independent units with built in solar cells and batteries, which would save money on cabling. Masdar was not immune to the global recession, however, and its budget was cut by $6 billion.  

Instead of the majority of Masdar’s above-ground-level surfaces being solar panels, solar generation has been outsourced to the 10MW PV and 100MW CSP plants outside the city.  Installing thousands of solar panels/reflectors in a single location is far cheaper than integrating them into the cityscape.  Maintenance and repair are also cheaper.

Unfortunately the effect of dust was not anticipated, and the performance of the PV panels has been significantly reduced. The PRT system has been scaled back due to lack of power, although budget cuts are also partly to blame.

So what can other nations take from this? As is often the case, the answer is “it depends”. Masdar's budget was significantly reduced, and the planners needed to save money.  Many towns don’t have the space to build solar farms on their doorstep (Masdar’s 10MW array occupies 55 acres) instead of integrating the panels into the city.  

On a utility scale the savings afforded by making this change were significant, but on a domestic scale the cost becomes manageable, being spread amongst thousands of householders. In developing nations, however, it may be more appropriate for the government to minimise costs and follow Masdar’s strategy.  In the end, money always talks, and developers/policymakers need to listen.

Solar CSP

CSP plants can be of the “tower” variety, using hundreds of mirrors to focus the sun’s energy onto a central point, or the “trough” variety, which use parabolic troughs to target a pipe running along the axis. Masdar’s plant, known as SHAMS-1, is of the latter design, and will use 786 mirrors occupying 2.5 square kilometres. SHAMS-1 is a hybrid facility, which uses natural gas to further heat the solar-steam, before passing it through a turbine. This approach is an efficient use of gas, and also allows the generating equipment to run at night. 

SHAMS-1 is on course for completion in 2013, and is projected to generate 210 gigawatt-hours per year: CO2 reductions equivalent to taking 30,000 cars off the road.  

SHAMS-1 is also falling victim to dust. This is due in part to the ongoing construction activity, and it remains to be seen how severely the plant's performance will be affected on an ongoing basis.  Cleaning the mirrors will be challenging in an area where water is invaluable.

Given its dual-fuel approach, the dust issue, and the price reduction of photovoltaic technology since SHAMS-1 was commissioned, the financial performance will be of particular interest.  Any figures published will only be relevant in this part of the world, however, where gas is cheap, insolation is high, dust is omnipresent, and water is scarce.  

Wind power

The gulf is not a windy region, and it is arguably more sensible to allocate investment to solar energy. However, Masdar is keen to embrace all forms of renewable energy. The company is developing a wind farm on Sir Bani Yas island with an expected capacity of around 30MW.  Also at the planning stage is a $200 million windfarm close to the Saudi Arabian border. Masdar's wind power projects will demonstrate the financial viability of wind power in this dusty and relatively wind-less region.

Passive Cooling

As one of the hottest regions on Earth, the Middle East uses a huge amount of energy to keep cool. The UAE's summertime peak electricity demand per person is more than three times that of Spain. The recent surge in the use of air conditioning has led to summertime blackouts as power stations struggle to meet demand.

Masdar's architects have tried to minimize the city's cooling requirements using techniques such as aligning the city's streets with the prevailing wind, making them narrow so as to channel the wind more efficiently, designing building facades that are able to minimize solar glare, and using thermally efficient construction materials.

Masdar will also utilise an old technology knows as the wind tower.  Evidence of wind towers dates back over 3000 years, to ancient Egypt. Only recently have architects come to appreciate their energy saving powers again, with the impressing need to minimize energy consumption.

Masdar's wind tower works in two distinct ways: On calm days it heats up and hot air flows upwards through the column. This establishes a street-level breeze and cools the surrounding area by a perceived 5°C.  When it’s windy the tower's louvres are adjusted to direct cool air down the column, exiting at street level. The narrow streets efficiently channel this air away from the base of the tower, maximising the cooling effect.

Masdar's officials predicted that the cooling effect in the plaza may be as much as 20°C, but whether the effect will be noticeable at all is now in question. However, Masdar designers Foster & Partners point out: "We want to make the structure itself a laboratory and get people talking about other possibilities.  We see it as an ongoing learning process."  

Active Cooling

Masdar is also pioneering the use of a solar absorption refrigerator for large scale district cooling.  This consists of a solar concentrating array, used to heat a transfer fluid.  Via the laws of thermodynamics, this fluid is used to generate cold water, which is piped around the city.  

Uniquely, the plant uses two types of solar concentrator: Initially, parabolic troughs heat thermal oil.  The energy is then transferred into a pressurised water circuit, which is further heated by Fresnel reflectors. Through using a combination of working fluids and solar concentrators, Masdar's absorption refrigeration plant is able to minimise the volume of water it requires, and maximise the temperatures achieved. This pilot project produces enough cold water to replace around 80 conventional air conditioning units.  

Conclusion

With the backing of a wealthy and determined government, proximity to an international airport, and an attractive climate for investors, few observers doubt that Masdar will be successful at least as a place of learning and business.  But how successful will it be in terms of carbon neutrality, and is this the best way to measure its success?  

Masdar's decision to scale back the amount of rooftop PV is particularly noteworthy. It does seem that large scale installations outside cities are the future:  Huge wind farms in the temperate regions and huge solar farms in the tropics are the current trend. Arguably, it is actually irrelevant if Masdar City is energy self-sufficient or not.  If it isn't, more solar or wind farms can be built.  If it is, some will say that Masdar had an unfair advantage with so much space and money. Most developed countries are investing heavily in renewable electricity, and in that respect, Abu Dhabi can't really claim to be any different: They are offsetting the demands of one city against various renewable power stations around the country. If the UK followed suit we could say that Greater London was 87% self-sufficient.

Masdar is undeniably accelerating the deployment of renewable power in the UAE, which is clearly  positive.  But the real lessons Masdar can teach us are about sustainable living:  Will the city's waste be negligible, her streets pollution free, her population's water demand minimal, and her energy demand per capita reduced?

In my opinion Masdar will be significantly ahead of other cities with respect to these criteria, and the international spotlight will help disseminate the design principles used. Sociological questions remain, but perhaps the type of people attracted by Masdar will be able to rise above such issues.

For more information visit;

http://www.masdar.ae/en/#masdar/all

Also of interest;

http://uk.news.yahoo.com/smog-eating-pavement-greenest-street-america-124500035.html?.tsrc=yahoo#IgE3zxs

References for this article available on request.

Peter Hume is a freelance copywriter specialising in the renewable energy industry.  He holds an MSc in Renewable Energy Development, a BSc in Physics, and has worked as a renewable energy consultant specialising in wind and biomass energy.

http://peterjphpositivefeedback.wordpress.com/author/peterjph/

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