Cogeneration and Clean Energy [ PDF ]

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Sustainable Solutions for Energy and Water Security in the United Arab Emirates

By Corinne Kisner

The United Arab Emirates is one of many countries in the Middle East and North Africa that is rich in oil reserves but faces a severe freshwater scarcity. With stresses due to climate change, population growth, surging industry, urbanization, and volatile international oil markets, the UAE has begun adopting alternatives to avoid exploiting hydrocarbon fuel and groundwater supplies. These technologies are forward thinking: combined heat and power generation provides energy efficiency, desalination produces potable water from the abundant supply of seawater, and concentrated solar power brings sustainability to the next level by eliminating the dependence on fossil fuel, emitting no greenhouse gases, and reducing the cost of an energy-intensive lifestyle. By adopting these technologies, the UAE has already and will continue to be a leader in energy sustainability in the Middle East and the world.

The UAE has the 5th largest proven oil reserve in the Middle East, amounting to nearly 10% of the world’s crude oil reserves. Oil exports are essential to the country’s economy, accounting for 30% of the total gross domestic product. Abu Dhabi, the major hydrocarbon and industrial power, holds more than 90% of the UAE’s oil resources, or about 92.2 billion barrels. Dubai, the trading, financial and tourist center, contains an estimated 4 billion barrels. Together, Abu Dhabi and Dubai account for 80% of the UAE’s income. Despite the huge wealth of oil, aggressive government policies have diversified the economy, and new policies aim to reduce the country’s greenhouse gas emissions by pursuing renewable energy and energy efficient technologies. In 2005, the UAE became one of the first major oil-producing countries to ratify the Kyoto Protocol to the UN Convention on Climate Change, demonstrating a commitment to emissions reductions. Since then, its renewable energy initiatives are unmatched in the region. Of particular note is Masdar City, slated to be the clean energy capital of the world. This revolutionary city in Abu Dhabi has received billions of dollars of investment in sustainable technologies. The city is designed as a 50,000-inhabitant zero-carbon and zero-waste community. Essentially, Masdar City will be an ecosystem running on solar power and providing information and expertise for the rest of the world.

Even with these efforts toward environmental sustainability, the UAE still faces significant challenges. With a population of 4.4 million and an electricity consumption of 56.6 terawatt/hours in 2006, the UAE ranks as the highest per capita energy consumer in the world. Strong economic and industrial growth, an increasing population, and urbanization trends have driven huge spikes in the demand for electricity. Energy consumption in the UAE has quadrupled in the last two decades, and current estimates predict that the domestic demand for power will double again by the year 2020. At the end of 2004, the total installed electricity generating capacity of the UAE was 12,800 megawatts, but the 7% annual growth in electricity demand will necessitate an increase in generating capacity, bringing the country’s electricity capacity to 19,400 megawatts by 2010. A report by the Dubai Chamber of Commerce and Industry called for $8 billion in investments to the electricity sector in Dubai over the next six to eight years to meet the growing demand. The emirate of Dubai alone must increase its power generation capacity to 9.5 gigawatts by 2010. Although energy consumption in the UAE is already high, it will continue to rise due to economic necessity. In the post-hydrocarbon age, the UAE will have to pursue renewable energy resources in order to reduce the costs of development, curb the harmful greenhouse gas emissions that contribute to climate change, and achieve energy security while remaining competitive in the global economy.

In addition to their high demand for energy, residents of the UAE consume an average of 550 liters of water each day, placing the country as the third highest per capita water user in the world after the United States and Canada. Annual water consumption in Abu Dhabi Emirate alone is estimated to be 2.49 billion cubic meters, and this figure is expected to more than double by 2020, reaching 5.86 billion cubic meters. The demand for water is more difficult to meet than the demand for energy, since the country is rich in oil but woefully lacking in freshwater resources. “Historically, all the UAE’s water requirements were met from groundwater obtained from shallow, hand-dug wells and the traditional falaj system of aquifers, as well as by the careful trapping of seasonal rainfall.” However, groundwater supplies have been nearly depleted, and the UAE has no rivers or lakes and limited rainfall. Ambitious agricultural and forestation projects, as well as a growing population with escalating demands, have strained the increasingly scarce natural water resources in the past two decades. With rising demand and falling supply, the UAE has turned to seawater desalination, boasting 19 facilities on the 2005 list of the 100 largest desalination plants.

Desalination involves evaporating saltwater under reduced pressure, condensing and capturing the steam, and then enriching the distilled water with minerals to create high quality potable water. This method requires large amounts of energy, but in an oil-rich country seeking freshwater resources like the UAE, this is a price worth paying. As the second-largest producer of desalinated water in the Middle East and North Africa, the UAE burned 9 million tons of oil equivalent in 2003 for desalination. By 2030, fuel requirements for desalination will reach 16 million tons of oil equivalent, or 20% of the country’s total primary energy demand. Although the UAE has the necessary oil resources available, energy markets are increasingly insecure due to the shift to the post-hydrocarbon age, and all countries would do well to move away from fossil fuels. Based on the country’s duel challenges of achieving water security and energy security in the face of climate change, cogeneration for power and desalination offers a tidy solution that is efficient, cost-effective, and environmentally friendly.

Combined heat and power (CHP) technology, also referred to as cogeneration, employs a single fuel source to produce both electricity and thermal energy. The integrated energy system works by combusting fuel (natural gas, oil, biomass, biogas or coal) to run an engine or turbine, which generates electricity to be used onsite or to be sold into the electrical grid. The hot exhaust gases produced through this combustion system are captured and converted into useful thermal energy in the form of steam or hot water; this thermal energy is used for the facility’s heating or cooling needs. In this way, CHP technology meets a facility’s thermal and electrical demands and provides economic and environmental benefits.

By integrating heat and power generation, CHP plants increase efficiency when compared with single-purpose plants. For four decades, the average fossil-fueled power plant in the United States has run at a 33% efficiency rate, wasting two-thirds of the fuel’s energy through heat vents. Capturing the exhaust heat for use as thermal energy results in a total system efficiency rate of 60-80%, meaning less fuel is required at CHP plants than at separate heat and power plants to produce the same energy output. The benefits of this increased efficiency include lower operating costs, fewer greenhouse gas emissions and air pollutants, and greater reliability and power quality. In addition to the direct financial benefits from reduced fuel consumption, CHP provides onsite-generated power in the case of grid blackouts and protects against unpredictable energy prices by allowing the facility to switch fuel inputs based on current prices. Using renewable inputs like biomass (especially agricultural waste) or biogas (the methane and carbon dioxide produced at landfills or sewage treatment plants) can further reduce fuel costs and the environmental impacts of generating the energy to meet demands.

Cogeneration can also be used to power desalination. The Shuweihat facility, located 250 miles west of Abu Dhabi City, burns natural gas (extracted in Abu Dhabi) to generate electricity, then uses the waste-heat steam to turn two turbines that also produce electricity, and then uses the turbine exhaust steam as the energy needed for desalination. The facility generates 1,500 MW of electricity and produces 450,000 cubic meters of potable water each day. Although the water is used primarily for irrigation, it is enough drinking water for 900,000 people. The two planned expansion phases will bring the facility’s capacity to 5,000 MW with a daily water production of 1.4 million cubic meters. By capturing and using the heat that would otherwise be vented into the atmosphere, the CHP facility increases its energy efficiency; by using the thermal energy to convert seawater to freshwater, the Shuweihat facility provides an integrated solution that tackles challenges on multiple fronts.

The UAE could take its sustainability initiatives one step further by capitalizing on an abundant natural resource: solar radiation. Each square kilometer of land in the Middle East and North Africa annually receives solar energy equivalent to combusting 1.5 million barrels of crude oil, an amount sufficient to desalinate 165,000 cubic meters of water per day. Combining concentrated solar power (CSP) plants with seawater desalination would have the same effect as CHP plants with desalination, with the added benefit of using solar power in the place of oil or natural gas. The harvested solar energy is used to generate electricity, and the waste heat from this process powers desalination. Some of the harvested solar energy can be stored for the night, and biomass can be used as a supplement to ensure constant electricity generation. Eliminating the need for hydrocarbon fuels eliminates greenhouse gas emissions and the vulnerability associated with insecure fossil fuel markets. At the present state of the art, CSP has a cost equivalent of $50/barrel of oil, with projected cost reductions due to economies of scale, mass production, and technological progress. Within ten years, costs will be equivalent to $25/barrel; by 2050, the cost of solar power could reach $15/barrel, making it a far more financially realistic input than fossil fuels.

In 2007, there was no installed CSP capacity in the UAE or in the entire Middle East and North Africa region. With the right government policies for rapid market introduction and development of CSP for electricity generation and desalination, this technology could replace the unsustainable extraction of freshwater within 10 or 15 years. According to Dr. Franz Trieb of the German Aerospace Center, “CSP is neither limited by the solar energy resource nor by its cost, but only by the possible speed of CSP capacity expansion.” With strong initiatives, the UAE could be a leader in this highly sustainable technology as a source of electricity and freshwater. Already, Masdar has made progress with solar technology and has plans to build the UAE’s first of many CSP plants, with a capacity of 100 MW, for operation in 2010. Similar projects on a larger scale will provide an excellent example for other countries in the region, demonstrating the ability to capitalize on abundant resources, sunlight and seawater, to produce the electricity and freshwater necessary to meet high demands. Concentrated solar power, along with combined heat and power generation, are truly sustainable sources of energy that will allow the UAE and other countries to pursue economic development and prosperity without sacrificing the environment or climate.

WINTER 2009 CLIMATE ALERT

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