Onsite power allows water purveyors to save on energy costs and boost utility performance.
By Ed Ritchie
The rapid growth of energy efficiency projects at water utilities is having a profound effect on America’s water industry. Utilities are saving energy and money thanks to better technology, expanded funding methods, and continuing pressure to operate in the most sustainable manner possible. Of course, with many utilities desperate to replace aging infrastructure, it only makes sense to use the opportunity for more energy-efficient equipment. When combined with an onsite energy resource, such as solar photovoltaic (PV) electricity generation or combined heat and power using biogas from a wastewater treatment plant’s anaerobic digester, the savings and sustainability achievements can be staggering.
For example, in New Hampshire, the Portsmouth Water System’s new Madbury Water Treatment Plant used both efficiency and sustainable building methods to earn LEED (Leadership in Energy and Environmental Design) Silver status. The $20 million plant started delivering water in August of 2011, after eight years of rigorous planning, testing, design, and construction to meet the US Green Building Council’s LEED standards, with categories including sustainable site development, water efficiency, energy efficiency, materials selection, indoor air quality, and innovation in the green building design process.
The facility replaced a 50-year-old plant at the same location. The design process involved optimizing energy efficiency in the water treatment process, and included solar hot water heating, plus source water heat pumps for heating and cooling, and a state-of-the-art dissolved air flotation treatment system designed to adapt to evolving standards in state and federal regulations. At 50 years of age, Portsmouth’s previous plant certainly had opportunities for improvement, but the luxury of building a new plant isn’t common for the majority of water utilities throughout the US. Nonetheless, there are many ways to achieve similar savings in the range of 20–30%, and with energy performance contracting, it’s possible to address energy at a water or wastewater treatment facility without incurring new costs.
Portsmouth implemented solar hot water heating, but generating electricity with PV solar panels could have an equally impressive impact on a site’s energy efficiency footprint, says Steve Birndorf, a project developer with Borrego Solar, Berkeley, CA. “Although California is one of the states we specialize in, we work also in western states and East Coast states such as Massachusetts, Maryland, Pennsylvania, and New Jersey,” says Birndorf. “Public utilities can’t apply directly for the federal incentive of 30%; however, if a third-party structure is used, such as a power purchase agreement, they can capitalize on it.”
Another option is to actually own the system and take advantage of comprehensive maintenance packages. “We guarantee the kilowatt-hours, so even though they own the system, we’re taking a long-term interest in its success,” adds Birndorf. “And power from the facility gives them stability in planning their power expenditures, so it’s a long-term hedge against energy price fluctuation because owners know how much their energy costs over 20 to 30 years.”
In New Hampshire, a third-party could have offered Portsmouth some significant savings because the state gives businesses a rebate of up to $50,000, or 25% of project cost, whichever is less. The rebate is $0.80 per watt for solar electricity, $0.07 per kBTU per year for solar hot water. Accelerated depreciation on solar systems are usually eligible for five-year accelerated depreciation if claimed as a business expense and amount to a deduction that can reduce tax liabilities up to 34% of a system’s cost.
Third-party contractors are experienced at dealing with state and federal incentive programs and handling the economics and operations are simple, Birndorf says. “Most utilities and water districts provide water services, and they’re not in the business of managing and maintaining and operating a solar array. So typically, in a third-party situation, we would sell the district energy at a rate that’s lower than what they’re currently paying, and we own and operate the system so they’re just buying kilowatt-hours.”
Growth Throughout the Pipeline
Performance contracting certainly isn’t a new concept, but the timing and access to such services has never been better, according to Chris Peluso, a project manager at CH2M, Englewood, CO. “The energy performance contracting world has picked up in utilities, and we’re going to see it explode over the next three to five years,” says Peluso. “People call it different names, such as Energy Service Companies, or ESCOs, but basically the energy savings pay for the creation and maintenance of the project, so you’re really starting to see growth in the water utility business, whereas previously was in municipal housing and schools.
In Wilmington, DE, CH2M improved the water utility’s energy picture with the installation of a low head pump station to drain their reservoir below the top fifth level of three feet, allowing a shift in well water pumping to night hours, rather than during costly peak day hours.
“They were using the same amount of energy, but because it’s off-peak the costs were reduced substantially,” explains Peluso. “So, we restructured the utility’s energy and saved about $750,000 a year. A big piece of assessing an operation is using submetering equipment, and the SCADA system is critical, because the ability to control pumps remotely is important. When we do real-time optimization where we are buying electricity in the real-time market, we turn pumps on and off based on those signals, and you need energy and production information and a good computer-based system to do that.”
Getting the maximum benefits from a SCADA system does indeed require software applications that can coordinate all the data, and management that can handle the risks, adds Larry Jentgen, principal engineer, EMA, Dallas, TX. Jentgen has served as project engineer, project manager, or principal-in-charge, for 21 large SCADA systems for water, wastewater, and electric utilities and worked as a principal investigator, with the AWWA Research Foundation (now WaterRF) and Electric Power Research Institute on multiple projects related to energy, water supply, and water quality management. So he’s seen the industry from all sides.
“There are a lot of technology upgrades, but what it takes is a very structured and sophisticated management attitude for the operations area,” says Jentgen. “The utility must be willing to assume some manageable risk with water to save substantial sums of money.”
Recent research has shown that the need is urgent. A survey conducted by EMA for the Water Research Foundation (WaterRF) as part of the project “Best Practices for Energy Management,” found energy is a significant operating cost for water/wastewater utilities, ranging from 2% to 35% of operating cost.
In the case of the JEA (Jacksonville Electric Authority), Florida, an EMA optimization process showed that the deferment of drilling one new well could have a substantial impact.
“Based on the optimization assessment, we discovered that they didn’t have to add that well, so they saved $1.4 million, and that was an immediate return on their investment, plus a recurring benefit in energy saved,” recalls Jentgen.
Furthermore, an automated software system for water supply and distribution added a key element for JEA. The system relies on SCADA and other sources of data to reduce costs and improve water operations. Savings on the investment came from a chemical cost reduction of $25,000–$50,000 per year, and capital infrastructure cost avoidance.
In water distribution, it’s no surprise that the biggest energy costs are typically the pumps, says Dan Lowenstein, senior vice president, Arcadis US, Highlands Ranch, CO. “Oftentimes we find that pumps are oversized, and that’s typical because engineers design for a wide range of flow conditions,” he explains. “But it’s possible to add secondary pumps that work 24 hours a day to cover normal conditions, and peak periods are when you run the larger pumps, rather than twenty-four-seven. So it’s a matter of understanding loads and demands on the treatment and delivery side.”
The Net-Zero Recipe: Codigestion
As and example of a utility that have pursued energy efficiency over the long term, Lowenstein cites the Gloversville Johnstown Joint Wastewater Treatment Facility in New York, a plant capable of producing 100% of its power. “It’s been done through a couple of projects but most notably by codigestion of food waste based on whey from a yogurt manufacturer. It’s the first potential net-zero plant in the United States.”
The road to net-zero energy operations has been a long one. The joint wastewater treatment facility treats up to 13.8 mg of domestic sanitary sewage daily, plus, a variety of industrial flows from food manufacturers, leather tanning, metal finishing, textile, and other major industries. In 2001, an analysis singled out the aeration system as the biggest energy load, consuming over 60% of the electricity demand, and in 2002, an investment of about $1 million allowed for upgrades that reduced its usage by 30%. Savings exceeded 1.3 million kWh per year, and amounted to a $195,000 reduction in the utility bill. But by 2010, the plant found a way to completely eliminate the operation’s utility costs.
Liberation from the grid came in stages. Another study, funded in part by NYSERDA (New York State Energy and Research Development Authority), revealed that supporting an upgraded combined heat and power (CHP) system with an increase in output from anaerobic digestion made sense economically and environmentally. (Arcadis authored a water/wastewater and energy management best practices handbook in 2010 for NYSERDA, and as a certified NYSERDA contractor it does walk-through assessments of water plants at no cost in New York.)
Upgrades included repairs to the secondary digester; a new separate 50,000-cubic-foot dual-membrane gasholder, new bubble gun mixers; and a new, 90,000-gallon equalization tank for high strength waste. Higher gas production justified rebuilding the 20-year-old CHP system for boost from 800,000 kWh to 1.8 million kWh annually, adding another $273,000 in annual savings, along with the $195,000 gained from the aeration system’s improvement. The final step to net-zero operations began as industrial companies and food processors relocated to the area and boosted the plant’s biogas production to fuel a larger set of two, 350-kW generators.
ISO Volunteers a New Standard for Energy
Studies such as those undertaken at Johnstown are an important tool in addressing energy efficiency, but water utility managers can also refer to another tool offered by the International Standards Organization, according to Bruce Lung, director of industrial programs, Alliance to Save Energy (Alliance), Washington DC.
“The first step in finding savings of up to 20 to 40% is to understand an organization’s true energy needs, and there’s a standard called ISO 50001, that was developed and released last year by the International Standards Organization, that can help end users with this approach,” says Lung. “It’s been adopted here in the United States by ANSI, and it helps companies and organizations decide how to manage energy effectively including developing an energy policy; how to manage energy procurement, how to dedicate staff, create documentation, and more.”
The ISO 50001:2011, Energy management system is a voluntary International Standard developed by ISO (International Organization for Standardization) and is available at www.iso.org/iso/iso_50001_energy.pdf. The standard gives organizations the requirements for energy management systems and provides benefits for organizations by establishing a framework for industrial plants; commercial, institutional, and governmental facilities; and entire organizations to manage energy.
An energy assessment was the first step for the Bucks County Water and Sewer Authority (BCWSA) in Bucks County, PA. The Authority commissioned a Watergy project, to validate their existing approach and explore opportunities to improve energy efficiency. The Alliance developed the term “Watergy” in 1997 to describe the strong link between water supply and energy use in municipal water systems. The project at BCWSA looked at the main energy-using applications in three pumping stations and four wastewater treatment plants. Recommendations included establishing an energy management policy, some simple energy conservation measures and some more complex capital equipment upgrades at a total estimated cost of $778,000 for savings of more than 4 million kWh of electricity per year, or roughly 20% of BCWSA’s annual energy usage. With estimated implementation costs of $361,000 a simple payback was just 2.2 years.
Distributed generation can also be a part of the energy efficiency solution, adds Lung. “If you look at the universe of wastewater treatment plants there about 15,000 total in the United States, yet a small number of 2000 to 3000 serve 80% of the population, and out of the total of 15,000, between 1,300 and 1,400 use anaerobic digestion according to EPA. Anaerobic digestion yields biogas that can be used to generate electricity in combined heat and power systems. But, out of the 1,300 or so plants with anaerobic digestion, only about 104 use that biogas to generate heat and power, according to EPA. The East Bay Municipal Utility District (EBMUD) has done a lot with renewables and combined heat and power in particular. They’re at the point where they can be energy neutral and sometimes have excess power that can sold back to the grid.”
100% Required, 120% Returned
The EBMUD, in Oakland, CA, recently launched its $32-million anaerobic digester expansion and doubled the plants capacity for renewable energy production. The higher production depends largely upon the codigestion of food scraps to produce biogas for a new CHP low-emission turbine producing 4.6 MW of power. The new installation boosts total output from three existing generators and puts EBMUD in the enviable position of producing about 120% of the energy it consumes, allowing it to surpass Portsmouth’s accomplishment of gaining net-zero status, and, for the time being, it’s the only wastewater treatment plant in North America to produce more renewable energy than it consumes.
There’s a direct connection between energy and water production and water utilities that can export power have great potential, according to Dr. Allan R. Hoffman, senior analyst, Office of Energy Efficiency and Renewable Energy, US Department of Energy (DOE). “We can’t talk about water without worrying about where the energy is going to come from to deliver it and treat it, and in terms of energy, you can put in power plants, but you have to worry about the water supply because they take a lot of water, so you can’t just put them anywhere,” says Hoffman. “The federal government has not addressed this issue competently, and I think there should be restoration of a National Water Council so energy and water people can address these issues in a national forum. You’re not going to solve these problems state-by-state. Water doesn’t respect state boundaries, so a regional approach is needed and globally as true as well.”
Wringing the highest efficiency out of the energy used for water is possible without help from the Feds, and that’s the main reason that demand response opportunities are booming for water utilities, according to Greg Dixon, senior VP of marketing, EnerNOC, Boston, MA. “We try to emphasize that if you are not currently involved in a demand response for energy efficiency program today you should immediately implement one because it’s literally money for nothing,” says Dixon. “It’s a huge market and, looking at water as a commodity, since 1990 the consumer price index has risen 400%. It’s a precious resource, yet the water infrastructure has been neglected. On the supply side, we help water utilities with their consumption of the electricity and natural gas and help them get the best prices. That would help them with energy efficiency and demand response so they can deliver their product at the lowest possible cost by using the least amount of energy.”
Savings from implementing a demand response program can be substantial. “We tell our customers that with a fully deployed energy management strategy the average wastewater treatment or water distribution plant can save 20% on their energy usage,” says Dixon. Typically in wastewater treatment plants, the energy savings start at raw water pumping and aeration equipment. “You can pump into lagoons,” he continues, “which is basically water storage, and curtail your electricity consumption during peak times, so those are very basic strategies that every wastewater plant can integrate into their operation. Onsite generation and cogeneration are opportunities as well. Overall sustainability absolutely affects utilities because they are in need of tools to make better energy management decisions. Part of that decision-making concerns the reduction of kilowatt-hours and BTUs consumed by the plant, and they want to be able to track reductions in dollar savings and the carbon savings associated with their efforts.”
Micro Management and Microbiology
Participating in demand response is part of the sustainability strategy, and also a profitable resource for the utilities operated by American Water, Voorhees, NJ. The company’s Climate Leaders Partner Goal Proposal with EPA is to lower its greenhouse gas emissions per the volume of water produced by 16% from 2007 levels, by the year 2017. The goal will be achieved primarily by improving the energy efficiency of the water pumping process, which accounts for approximately 90% of the company’s greenhouse gas emissions. But recent developments have opened up a niche that improves pump performance in demand response programs. The company has launched a pilot program with ENBALA Power Networks, Toronto, Canada, a provider of energy management and consumption technology. The ENBALA system controls the electrical power at water treatment plants so their overall energy use provides grid balance to electricity system operators.
With the ENBALA system, our energy can be adjusted on a micro basis, such as a wastewater plant’s aeration motors, says Paul Gagliardo, manager of Innovation Development at American Water. “The blowers run maybe 20 minutes out of an hour, and we can adjust or shift the schedule or ramp down other loads, such as variable frequency drive pumps in a response from an ISO, and it helps them achieve good balance. So, essentially, we don’t use more or less electricity. We just shift the time of its use, and that’s valuable to the ISO, which has a day ahead auction that companies bid into to participate in the program, and the prices are around $35,000–$50,000 per megawatt per year. So it’s quite valuable to the ISO, and some of that value comes back to the utility and customers.”
American Water has also found that solar PV offers attractive energy efficiency gains and has a demonstration program at its Canoe Brook Water Treatment Plant in New Jersey. The system uses 538 solar modules that float on the station’s reservoir, and produces about 135,000 kWh for an estimated energy cost savings of $16,000.
Another technology is a wastewater treatment concept that reduces the dissolved oxygen in wastewater to preferentially grow certain microorganisms that can perform at the same treatment levels as the conventional aerobic microbiology, but require just half the energy usage.” In 2011, the US Patent and Trademark Office awarded American Water a patent for NPXpress, a more affordable and sustainable method to remove nutrients such as nitrogen and phosphorus from wastewater. Removing these nutrients has traditionally been a difficult and costly process that involves the addition of extra chemicals and high concentrations of dissolved oxygen. The new patented process, credited to three American Water scientists, creates savings in both energy and process chemicals used for wastewater treatment and has successfully reduced aeration costs through reduced aeration energy consumption at the company’s Mapleton and Jefferson Peaks treatment plants. It’s slated for installation at six additional locations.
Reducing energy through process modifications can result in impressive gains. At Mapleton, the plant’s overall energy load decreased by about 35%. The Jefferson Peaks plant saw reductions of about 37%, and reduced demand charges from the electric utility contributed to additional savings. In assessing the program from a return on investment perspective, the simple payback numbers were 3.1 months for Mapleton, and 4.6 for Jefferson Peaks.
So far, we’ve covered a variety of energy efficiency solutions for individual projects, but what about incorporating such projects in a citywide water infrastructure approach? A recent announcement from Honeywell Building Solutions and the Western Virginia Water Authority in Roanoke, VA, offers a great example of combining energy efficiency upgrades with an Advanced Metering Infrastructure (AMI) program. The $32-million project is backed by a guaranteed systemwide water infrastructure improvement program designed to upgrade meter accuracy and leak detection at the retail customer level, a treatment plant program that includes energy retrofits, plus conservation measures at the Authority’s pump stations and four main water supply plants. Some of the larger items among the retrofits include HVAC upgrades, pump replacements, and peak shaving generator installations. Electricity consumption is expected to drop by nearly 5 million kWh annually.
It’s not unusual for a water utility to account for about half of a city’s energy bill, says Dave Robinson, energy market manager at Honeywell. “A 30% improvement in efficiency is well within the realm of possibilities, and the biggest problem in Virginia was water loss and unaccounted for water. With the use of a really good asset management system you know the details down to a section of pipe in a certain part of the city that uses a certain component and its installation date. By integrating all those data points you can come up with a strong capital improvement plan and energy efficiency. It’s a significant investment but well worth it.”
In Western Virginia’s case, the upgrades are expected to be worth savings of more than $1 million in annual electricity and operating costs, plus an additional $1.5 million in revenue through increased water meter accuracy, as guaranteed by Honeywell. Much of the savings can be credited to a new data management system and zone metering capabilities to help the Authority identify potential leaks in its water system.
All told, Honeywell’s project shows that water and energy efficiency improvements can be integrated into powerful solutions that span a system from water treatment to the retail customer’s meter. Moreover, Honeywell and other energy service contractors have built a strong foundation and can look forward to an unprecedented opportunity in the US. According to a report from Pike Research, the ESCO market for energy efficiency project installations and services in the US exceeded $5.1 billion in 2011.
Public policies such as President Obama’s 2009 executive order mandating all federal agencies to achieve a 30% reduction in energy use by 2015 encourage a greater emphasis on energy efficiency. Ultimately, this market is expected to continue to grow faster than the domestic economy and reach at least $13 billion in sales by 2020. Under a more aggressive scenario, the ESCO market could reach $16 billion by 2020. Billions of dollars in growth that includes energy-efficient water infrastructure is more than good news for an industry that has seen more than its fair share of neglect. And the pace of growth will accelerate with continuing innovation and technology improvements.
Author’s Bio: Writer Ed Ritchie specializes in energy, transportation, and communication technologies.