Sample Essay Paper on Large Scale Energy Efficiencies and Water Savings

Large Scale Energy Efficiencies and Water Savings

Abstract

The world faces a major challenge in ensuring efficiency in the water and energy sectors. Although most efforts to promote efficiency in these two sectors have always tended to be disaggregated, recent research has shown that more efficiency in these two sectors can be achieved through synergy. The realization that water treatment and distribution are energy intensive processes informs the need for cooperation by the water and energy centers in our cities. In addition, research has established wastewater treatment plants can achieve the dual benefit of reclaiming wastewater and generation of energy and this is an opportunity that should be tapped as a way of bringing more efficiency in energy and water.

Introduction

Achieving efficiency in the energy and water sectors has become a major focus by many urban authorities, informed by the continued population explosion in urban cities that has stretched these vital resources to their limit. The emergence of climate change has not made the situation better and day by day, making energy and water available to the populations is a headache for all energy and water agencies in the world. Recently, the term watery has been developed stemming from the convenient alliances by the water and energy authorities to foster efficiency in these sectors and promote conservation.

 This approach has come in handy for many cities, as it has helped them realize significant energy, water, and monetary savings through technical and managerial interventions in water and wastewater systems. By doing so, it has become possible to ensure that consumer’s access quality water while simultaneously ensuring that minimum possible energy and water are used (Howe and Cynthia 271). The goal of this paper is to look into the whole issue of water and energy efficiencies in urban cities, review the progress and challenges, and make recommendations for future water and energy conservation efforts. We will also review case studies to demonstrate the success of this noble initiative in three cities.

Water and Energy Conservation

According to Howe, Joel, and Jim, watery is a valuable resource that is yet to be fully tapped .It has been proved a cost-effective measure that takes a short time for the benefits to be realized. The savings that ensue from these measures make it possible to avail other critical services to the public (123). For those who bear the financial burden in the provision of public services, efficiency in the provision of energy and water is among the few available cost-effective options available that will help meet growing demands for vital services such as electricity, water supply, and wastewater treatment. Over and above the direct savings in energy and water, the improvement of efficiency in urban water utilities lead to significant reductions in operating costs and thereby better services. It also has a direct link with reduction of carbon emission, which helps in curbing climate change.

Many players in the water and energy sectors are yet to fully comprehend the integral relationship between water and energy and where the understanding exists; there is poor exploitation through well-articulated and holistic approaches. The water-energy relationship stems from the fact that the treatment of water and the transportation of the treated water to the consumer are extremely energy intensive ventures. Globally, energy has been listed among the three topmost cost items in water utilities, coming only second to labor costs. In developing countries, energy is actually the highest cost element in the supply of water (Howe, Joel, and Jim 126).  

Experts have studied the factors that make water supply such an energy intensive process and why so much water is squandered in the process and they have found out that most of the water distribution channels around the world leak. This situation happens even in the industrialized countries attributed to an aging water infrastructure. The loss of water through leaks also affects the energy and cost of energy that goes to the water network with no output (Escobar and Andrea 18).

Research studies in water efficiency have found out that in the developing countries, about one third of the water that enters the distribution channel is lost through leaks and systemic inefficiencies. For instance, In Latin America, Mexico has been found to lose a third of the water that was intended to have reached the consumer. Brazil is even worse, where on average, 44% of the water in the distribution system is lost through leakage. Most of the large cities in Latin America lose about 40% of the water on average through leaks.  In South Africa, about 40% water loss has been reported in most of the big cities (Howe, Joel, and Jim 127). 

In considering technical and managerial approaches to water and energy efficiencies, it has been noted that most cities have focused their efforts towards demand-side management or conservation upon the arrival of the water to the end user while ignoring the tremendous energy gains that could be attained as the water navigates the distribution system (Riepl 237). A summary of some of the measures that can be employed to achieve efficiency downstream has been formulated by Howe, Joel and Jim (126) as follows:

  1. Electricity Rates – the demand for electricity should be reduced during peak period rates.
  2.  Electrical Installations – the optimization of power factor with capacitors and reduction of voltage imbalances
  3. Operations and Maintenance – Ensure routine pump maintenance as well as deep well maintenance and rehabilitation.
  4. Production and Distribution – Use new and efficient pumps, motors, and impellers. Also make efforts to optimize the distribution network by removing unnecessary valves, sectoring, and installing variable speed drivers and regulating valves.

Energy and Wastewater Treatment

A lot of focus has been put recently on ensuring efficiency of water and energy through wastewater treatment. Terms such as the ‘water energy nexus’ have been put forth. Research has shown that treatment and conservation of wastewater brings with it great energy potentials. This is good news considering that vast quantities of energy are spent in the treatment of wastewater. For instance, energy statistics in the United States have revealed that about 4% of electricity consumption in the US is used in moving and treating wastewater. The cost of energy in wastewater treatment plants goes as high as 60% in some countries (Barceló and Petrovic 129).

The global water crisis which is worsening every day has caused many urban communities to embrace the reclamation of wastewater which has gone into key uses such as irrigation, cleaning the cities, and use in bathrooms. In the process of reclaiming wastewater, landmark discoveries have been made. One of the discoveries is that wastewater contains nutrients such as nitrogen, phosphorous, and potassium which are very beneficial to plants when these affluent are used for irrigation (Wu, Weeping eat al 11). A perfect example is the City of Abu Dhabi in the UAE where affluent wastes have been used in irrigating the city and greening and beatification programs relying on wastewater have been very successful in the city. This has transformed a desert city into a green city (Shahid and Mushtaque 12).  Wastewater has also been found to be rich in organic matter which contains energy that can be extracted through anaerobic processes. Researchers have suggested that wastewater energy extraction is capable of generating ten times the energy put into the wastewater treatment plants and this brings a viable energy solution (Libhaber and Álvaro 165).

City of Los Angeles Hyperion Wastewater Treatment Plant

The Hyperion Wastewater Treatment Plant receives on average a daily flow of 320 to 400 MGD. Upstream wastewater reclamation plants discharge biosolids to Hyperion which results in an influent wastestream containing 360 to 400 ppm of total suspended solids. The Hyperion Energy Recover System (HERS) was launched in 1987 and it generates energy from biosolids through two distinct processes. In the first process, biogas from anaerobic digestion fuels three gas turbines. Each turbine has the capacity of generating 4,500 kilowatts of electrical energy. Waste heat from the turbines is sent to heat recovery boilers which generate steam at high pressure. This steam is used to drive turbine which generate more electricity.

In the second process, biosolids from the digesters are dehydrated and the resulting powder is sent to a fluid bed gasification multi-stage combustion chamber. About 20% of all the biosolids emanating from these wastewater treatment plants are burned through this process. During this process an ash byproduct is generated which is used in an offsite cement manufacturing process. HERS generates 20 megawatts of electrical energy on average and an estimated $12 million annually worth of electricity costs are saved every year.

Seattle Metro Renton Water Reclamation Plant

Unlike most of the other wastewater treatment plants, this plant does not use the biogas onsite for heating and cooling. Instead, Metro has established relationships with local utility suppliers who buy the biogas for offsite use. The plant has then replaced its potential in-plant use with electrically operated heat pumps that remove heat from the effluent. This is a more cost effective approach supported by the low electricity costs in Seattle area as well as grants and other assistance from the electric utility. Metro also runs another program known as Metro Therm which uses effluent for offsite heating and cooling of buildings at privately owned facilities.

Seattle Metro has implemented several energy conservation measures at its Renton Plant which include the insulation of the digesters, recovery of waste heat from blowers, use of energy efficient motors and variable speed drivers, and installation of motion detectors to control lighting in conference rooms.

Wastewater Treatment in Abu Dhabi, UAE

The UAE water production capacity is about 510 million gallons every day, out of which 80% is desalinated seawater. Almost all of the wastewater in the emirate o Abu Dhabi is recycled, treated and used for irrigation. The treated wastewater is used in fish hatcheries, farms, municipal and commercial sewer systems, and industrial toxic waste treatment. The remaining sludge is disinfected and used as a natural fertilizer. Wastewater ozone treatment systems support a wide range of activities ranging from reduction of biological waste to complete purification and sanitation as required by drinking water standards (International Business P.I. 66). 

Conclusion and Recommendations

The world is faced with major challenges as far as ensuring access to clean energy and water for all is concerned. The need to mitigate climate change through clean energy and improvement of energy efficiencies has never been more real so is the need to adopt water conservation measures. Although water and energy efficiency measures have tended to be disaggregated in the past, with little or no synergy from the two sectors, the reality of cooperation in the two sectors is now at hand. Judging from the impressive successes by many cities including Abu Dhabi, Seattle Metro, Los Angeles, among others, there is enough justification for all cities across the world to put more efforts in fostering efficiency in the energy and water sectors. . The realization that water treatment and distribution are energy intensive processes informs the need for cooperation by the water and energy centers in our cities.

Works Cited

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Escobar, Isabel C, and Andrea Schäfer. Sustainable Water for the Future: Water Recycling Versus Desalination. Amsterdam: Elsevier, 2010. Print.

Howe, Carol, and Cynthia Mitchell. Water Sensitive Cities. London: IWA, 2012. Print.

Howe, Carol, Joel B. Smith, and Jim Henderson. Climate Change and Water: International Perspectives on Mitigation and Adaptation. Denver, CO: IWA Pub, 2010. Print.

International, Business P. I. How to Invest, Start and Run Profitable Business in the United Arab Emirates Guide. S.l.: Intl Business Pubns USA, 2013. Print.

LeBlanc, Ronald J, Peter Matthews, and Roland P. Richard. Global Atlas of Excreta, Wastewater Sludge, and Biosolids Management: Moving Forward the Sustainable and Welcome Uses of a Global Resource. Nairobi, Kenya: United Nations Human Settlements Programme (UN-HABITAT, 2008. Internet resource.

Libhaber, Menahem, and Álvaro Orozco-Jaramillo. Sustainable Treatment and Reuse of Municipal Wastewater: For Decision Makers and Practicing Engineers. London: IWA Publishing Alliance House, 2012. Print.

Riepl, David. Knowledge-based Decision Support for Integrated Water Resources Management with an Application for Wadi Shueib, Jordan. Karlsruhe: KIT Scientific Publishing, 2012. Internet resource.

Shahid, Shabbir A, and Mushtaque Ahmed. Environmental Cost and Face of Agriculture in the Gulf Cooperation Council Countries: Fostering Agriculture in the Context of Climate Change. , 2014. Internet resource.

Wu, Laosheng, Weiping Chen, Christine French, and A C. Chang. Safe Application of Reclaimed Water Reuse in the Southwestern United States. Oakland, CA: University of California Agriculture and Natural Resources, 2009. Print.