In an era of increased concern about limited water supplies, energy consumption, water quality and climate change, the pressure on water utilities to deliver greater efficiency and operational effectiveness is greater than ever for this energy-intensive industry.
According to the U.S. EPA, water utilities across the United States and elsewhere in North America are saving substantial amounts of water through efficiency programs. These savings often translate into capital and operating savings, which allow systems to defer or avoid significant expenditures for water supply facilities and wastewater facilities. Drinking water systems can implement efficiency measures and still deliver an unchanged or improved level of service to consumers.
Energy Efficiency
According to a report by the U.S. Government Accountability Office (GAO), technologies and systems exist to help improve the energy efficiency of the drinking water and wastewater industry, but costs and competing priorities have slowed their implementation. The report focused on the amount of energy needed to supply, use and treat water. GAO found a variety of approaches can improve the energy efficiency of drinking water and wastewater processes, but determining the most appropriate solution depends on the circumstances of a particular system and requires an understanding of the system?s current energy use.
The vast majority of energy consumed by water utilities is used to pump water. Approximately 90 percent of American Water?s own electricity consumption and 83 percent of its greenhouse gas emissions are related to pumping water ? initially from its source to treatment and storage facilities, then later on to customers. Improving the efficiency of pumps, then, is among the most important measures water utilities can take to decrease their carbon footprint.
Research has shown that the average ?wire-to-water? efficiency of existing ?in-field? water utility pumps is about 55 percent. New installations are designed to achieve efficiency ratings of between 76 percent and 82 percent. American Water sees this as a major opportunity to decrease its carbon footprint. By replacing or refurbishing older pumps, studies have shown that pump efficiency can be restored to their original efficiencies of 76 to 82 percent. This often means a 10 to 20 percent improvement, or more.
The company has increased use of variable speed drives on pumps by installing them on at least one pump in many of its stations or plants to vary the pumping rate so it only pumps what is needed at a specific time, thus, saving energy. American Water also launched a pump efficiency initiative that identifies inefficient pumps and either replaces or rehabilitates them to improve efficiency.
Indeed, water and wastewater utilities strive to focus on pump management and maintenance in such a way that addresses energy demand and power usage either through traditional approaches or improvements and innovations. At 85 percent, energy comprises the largest typical life-cycle cost for a potable water pumping system with 80 percent run time, followed by maintenance at 10 percent. New, renewable energy technologies, such as solar and wind power, hold the other key to reducing the emissions that contribute to climate change.
Solar energy generates electricity without producing harmful greenhouse gases and produces maximum output at times of peak demand, when electricity is of highest value. Solar energy can be purchased from a third-party supplier or owned outright. In addition to environmental benefits, solar energy affords a financial hedge against rising energy costs, as well as new revenue streams through the sale of tradable solar renewable energy credits. Financial incentives may also be available in the form of rebates and tax credits from local utilities and local, state and federal government.
In 2011, New Jersey American Water installed solar panels on a reservoir at the Canoe Brook Water Treatment Plant in Millburn, N.J. This is the first solar array on the East Coast on a body of water designed to withstand a freeze/thaw environment. The 400 solar panels measure 110 ft by 110 ft and rest on a docking station designed to float on the water?s surface. The array generates 112 kilowatts of DC (direct current) power, which is converted to AC (alternating current) power. This solar installation produces 135,000 kilowatt-hours of energy each year, saving more than 56 tonnes of carbon emissions.
Local wind farms produce clean, renewable energy with no design, construction, operation or maintenance commitments on the part of the utility. Since wind power is feeding energy to the electricity service provider?s grid, there is no perceivable difference in the energy being provided to the company. Because wind power is generated off-site, enrolling in a wind energy program is ideal for smaller utilities that want to commit to greener operations but can?t undertake the level of commitment required by solar installations.
American Water is the first U.S. water utility to use the Smart Grid technology of ENBALA Power Networks. This innovative technology manages the way American Water?s treatment plants and pumps use electrical power. Instead of adjusting electrical generation to match changes in electrical demand, the network adjusts demand, enabling electrical equipment to consume more energy when demand is low and less when it is high. This provides Grid Balance to electricity system operators.
Water Loss Control
For water utilities, detecting and repairing leaks is one of their main components for water conservation. Deteriorating infrastructure, fluctuating water temperatures, soil movement, vibrations and water pressure changes are just some of the factors contributing to water leakage. Not only do leaks account for lost water, but they can also allow contaminants into the system that can endanger public health. It is estimated that up to 10 billion gallons of raw sewage is released into our waterways every year as a result of blocked or broken sewer pipes.
According to the American Society of Civil Engineers? Report Card for America?s Infrastructure, national drinking water/wastewater systems received a grade of a D. Over the last several years, many studies have been undertaken to estimate water loss. Regions of developing countries are experiencing greater water loss than regions in developed countries. Non-revenue water levels average just over 20 percent in the United States.
Water conservation is also crucial. Due to their low rate of replacement, broken and leaking pipes currently result in 1.7 trillion gallons of water ($2.6 billion) lost every year. Early detection and repair of leaks saves water and energy and reduces repair costs.
Finding and stopping leaks quickly reduces repair costs, chemical use, energy consumption and associated greenhouse gas emissions. With enhanced metering systems, we are better positioned to educate our customers about how they can save water and money by taking steps to conserve. Building upon our pioneering work with acoustic leak detection systems and improved metering techniques, American Water has intensified our efforts to find leaks in our systems more rapidly and reduce water lost due to leaks (non-revenue water).
Supply Chain Efficiency
Many people tend to limit their view of supply chain management to a hard goods environment such as manufacturing and distribution. In fact, a supply chain can be abstracted to a series of transactional boundaries where value is exchanged for compensation, and it may consist of only a single supplier and customer. The supply chain agenda at leading utilities has changed substantially in recent years. The original focus on cost savings and organizational efficiency has evolved, with increases in activity across all utility sectors to include the challenges of cost containment, supply assurance and risk management.
The most significant benefit of centralizing supply chain activity in a utility comes from strategically sourcing the goods and services that are purchased. American Water is building a leading Supply Chain organization to address the increasing challenges of managing its supply chain in a sustainable, reliable, and cost effective manner. This has resulted in a number of efficiency improvements, such as:
? Consolidation of purchasing volumes across the company has resulted in significant savings for commonly purchased items ranging from water treatment chemicals to construction services.
? Materials such as pipes, valves and water meters have been standardized with resulting savings in both the initial purchase price and on-going maintenance costs. Changes in meter reading technology are reducing the effort required to read meters and the rework associated with missed reads.
? Ongoing work to source American Water?s fleet of vehicles has resulted in a 10 percent reduction in the number of cars and trucks the company maintains while removing older, less fuel efficient vehicles from the fleet and better aligning vehicle specifications to the needs of the work force.
? As noted above, ENBALA?s Smart Grid Technology is being used to help better manage energy consumption. Other efforts are reducing consumption of things as diverse as office paper and laboratory services.
As discussed in this paper, water utilities are faced with enormous challenges, and efficiency remains a top priority. Like all companies, American Water is challenged to find innovative ways to operate efficiently for the benefit of the company and its customers. In reducing its own carbon footprint, American Water has introduced innovations that it hopes will set the stage for operational efficiency, as well as more environmentally friendly practices throughout the industry.
This paper is an excerpt of the recently released white paper from American Water, ?Creating Operational Efficiencies in the Water Industry.? To view the full paper, visit http://pr.amwater.com/PressResources/white_papers.cfm.?
