Harnessing Sun and Wind Energy for Water Treatment
- By John Young
- May 19, 2010
As a partner with the U.S. Environmental Protection Agency’s Climate Leaders program, American Water set a goal to lower its greenhouse gas (GHG) emissions per volume of water produced by 16 percent by the year 2017. Considering that we treat, pump and deliver 1 billion gallons of water a day, the goal is significant.
A large portion of the reduction will come from increasing pump efficiencies, but 6 percent (37 percent of emissions reduced) will be achieved by increasing the use of renewable energy sources – either generated onsite or purchased.
In 2005, the company launched its use of alternative energy by investing in solar technology for the Canal Road Water Treatment Plant in Somerset, N.J., and enrolling in wind power for the Yardley Water Treatment Facility in Yardley, Pa. While each project has different advantages and levels of operational commitments, both have achieved ecological benefits and cost efficiencies beyond original projections.
Solar energy generates electricity without producing GHGs 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. After analyzing the rebate incentives, energy cost savings and other factors, New Jersey American Water chose to invest in owning the system.
The company installed a ground-mounted dual-array photovoltaic (PV) system at its 80-million-gallon-per0day (mgd) Canal Road facility about five years ago, and expanded the system to include additional ground and basin-top mountings in 2006 and 2007. The PV system, the second-largest ground-mounted system east of the Mississippi River, includes 3,718 solar modules, supporting steel structures, wiring, two 225 kWac inverters and one 100kWac inverter, revenue-grade metering and an Internet-based data-acquisition system.
The project required approvals from the Franklin Township Planning Board, Somerset County Soils Commission, Historical Buildings Commission, Delaware and Raritan Canal Commission, and the New Jersey Department of Environmental Protection as well as the town engineer and local code inspectors. When the project was completed, officials with the state Clean Energy Program and the local electric service company inspected and approved the facility.
The first phase of the project was constructed for approximately $1.6 million, after a $1.9 million rebate from the Clean Energy Program. The solar panels make up about two-thirds of the overall capital cost. The balance is for other equipment — inverters, transformers, AC and DC disconnects, Internet data-acquisition system, and wiring and conduit — and includes engineering, installation labor, and overhead costs. Phases two and three cost $500,000 and $640,000 after rebates, respectively. New Jersey American Water recouped its investment in less than five years.
The system, which supplements 20 percent of the peak usage power needed to run the plant, reduces energy usage by 817,000 kilowatt-hours of AC a year. This prevents 1,875 pounds of nitrogen oxide, 3,927 pounds of sulfur dioxide and 1,115,000 pounds of carbon dioxide from being emitted into the air. According to EPA and the U.S. Climate Technology Cooperation, this savings in carbon dioxide pollution is equivalent to planting 125 acres of tree seedlings or preserving 5.6 acres of land from deforestation.
“The benefits of this system are significant,” said Mike Wolan, senior engineering project manager, New Jersey American Water. “With energy production tracking 13 percent higher than predicted, both the environmental benefits and the return on investment are exceeding original estimates.”
In addition to the energy cost savings, the system allows New Jersey American Water to sell tradable, solar-specific Renewable Energy Credits (RECs) that electric marketers need to meet the N.J. Renewable Energy Portfolio Standard. In 2009 the company received $553,000 of solar credits, which were credited to the customer's benefit, thereby reducing their overall costs.
Unlike solar energy, wind energy is only 30-percent efficient, because it relies on natural windy conditions to generate power. However, since the wind power is feeding energy to the electricity service provider’s grid, there is no perceivable difference in the energy being provided.
Pennsylvania American Water committed to operate its 6-mgd Yardley Water Treatment Plant with 100 percent pollution-free electricity by enrolling in a wind power program in June 2005. Offered by the local electricity service provider, PECO, the PECO WIND program provides electricity using state-of-the-art windmills, as supplied by wind energy developer, Community Energy, Inc.
Through this program, the company purchases 1,603,200 kWh of green power annually to power the entire facility, which is the environmental equivalent of planting more than 119 thousand trees or not driving 1.5 million miles each year.
According to Jeff Chamberlain, Pennsylvania American Water production superintendent in southeastern part of the state, the commitment to wind power didn’t result in cost savings but did help the facility become more efficient. The company found additional cost savings to offset the $0.02 per kWh increase in the plant’s electric bill.
“The process of investigating how to go green without increasing costs led us to enroll several of our facilities in a nightrider program," Chamberlain explained. "This required us to change our operations schedules to increase energy use at night, when demand is lower and we can take advantage of lower rate blocks.”
Because the 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.
Making the commitment to invest in green energy is good for the environment, as well as good for the company and its customers. Water companies throughout the United States should investigate local incentives for renewable energy as well as implement energy efficiency programs to reduce environmental impacts, energy costs and their future exposure to higher electricity costs.
John Young is chief water technology officer for American Water, the nation’s largest investor-owned water and wastewater utility company, serving approximately 16 million people in 35 states and Ontario and Manitoba, Canada.