Water Efficiency at Public Power Electric Utilities

Transcription

1 Water Efficiency at Public Power Electric Utilities September 29, 2010 GWPC Annual Forum J.P. Blackford Senior Environmental Services Engineer 1

2 What is APPA The American Public Power Association (APPA) is the national service organization representing the interests of the more than 2,000, not-for-profit municipal and other state and local community-owned electric utilities that collectively provide electricity to approximately 45 million Americans. These utilities, or public power systems, are among the most diverse of the electric utility sectors, representing utilities in small, medium and large communities in 49 states (all but Hawaii), Puerto Rico, American Samoa, and Guam. Seventy percent of public power systems are located in cities with populations of 10,000 or less. Created in 1940 as a non-profit, non-partisan organization, APPA s purpose is to advance the public policy interests of its members and their consumers, and to provide member services to ensure adequate, reliable electricity at a reasonable price with the proper protection of the environment. Overall, public power accounts for about 15 percent of all kilowatt-hour sales to retail electricity consumers. Approximately 46% of the megawatt hours of electricity produced by public power systems are generated using coal. In addition, more than 80% of communities operating public power utilities also manage water utilities that provide drinking water to residential, institutional, commercial and industrial customers.

3 Locations of Coal-Fired Electric Units Note: This map depicts all coal-fired units, regardless of ownership

4 Energy-Water Nexus Source: Presentation by Mike Hightower, Sandia National Labs

5 Water for Energy Thermoelectric-power generation water withdrawals were an estimated 201 Billion gal/d in 2005, about 3 percent more than in In 2005, thermoelectric freshwater withdrawals accounted for 41 percent of all freshwater withdrawals. Nearly all of the water withdrawn for thermoelectric power was surface water used for once-through cooling at power plants. Twenty-nine percent of thermoelectric-power withdrawals were saline water from oceans and brackish coastal water bodies.

6 Trends in estimated water use in the United States, Source: Estimated Use of Water in the United States in 2005, Circular 1344, U.S. Geological Survey

7 Trends in total water withdrawals by water-use category, Source: Estimated Use of Water in the United States in 2005, Circular 1344, U.S. Geological Survey

8 Water Usage for Electricity Generation Water withdrawals for thermoelectric power generation account for 50 percent of all daily water withdrawals in the U.S. Water consumption accounts for 22 percent of all nonagricultural water consumption. Current projections suggest that fresh water consumption for electric power generation, using current technologies and approaches, could triple by 2030 relative to 1995 water consumption. Much of the projected growth in electric power demands will be in regions of the country with already limited water supplies, such as the Southeast, Southwest, and West. Reducing fresh water use and particularly fresh water consumption in future electric power generation could be a major challenge and research priority.

9 Water Usage for Electricity Generation Cooling Systems Open Loop About 54 percent of current U.S. generating capacity Requires access to a large body of water Impingement on intake screens and entrainment in the cooling water of aquatic life Drought or other circumstances can restrict power-plant operations due to discharge water temperature Closed Loop Evaporation of the cooling water in a wet cooling tower or cooling pond Most electric generating installed since the mid-1970s Withdraw less than 5 percent of the water withdrawn by open-loop systems, but most of the water withdrawn is consumed through evaporation. Pollution Control Flue gas desulfurization (FGD) Wet scrubbing consumes about gal/mwh more water than dry FGD Carbon Capture & Storage (CCS) for CO 2 control Parasitic Energy Losses and additional water needed could increase water demand by 40%

10 Water Usage in a Wet Recirculating Cooling Water System For a 520-MW Coal-Fired Boiler Source: DOE/NETL Estimating Freshwater Needs to Meet Future Thermoelectric Generation Requirements (2009 Update) DOE/NETL-400/2009/1339

11 Cooling Systems by Technology and Water Source Source: DOE/NETL Estimating Freshwater Needs to Meet Future Thermoelectric Generation Requirements (2009 Update) DOE/NETL-400/2009/1339

12 How Much Water Does It Take to Make Electricity? Source: IEEE Spectrum, April 2008 ( Source: California s Energy-Water Nexus: Water Use in Electricity Generation Southwest Hydrology, September/October 2007

13 Water Usage for Electricity Production Source: Reducing water use in electric power generation reliability and environmental considerations; Presentation at 2010 UCOWR/NIWR CONFERENCE by Mike Hightower, Sandia National Labs

14 Water Demand for Various Electric Generation Technologies

15 Reclaimed Water Reclaimed wastewater is a source of water for thermoelectric-power generation, especially in States with arid climates or otherwise limited water resources. Arizona, California, Florida, and Texas are among the States that use significant quantities of reclaimed wastewater for thermoelectric-power generation. In Arizona, about 59 MGD of reclaimed wastewater was associated with thermoelectric-power generation. Ownership of WWTP and Electric Utility by the City Some Public Power Utilities already provide reclaimed water for usage Jacksonville, FL (JEA)

16 Reclaimed Water Usage Note: This represents the entire utility sector, not just public power Source: Department of Energy, Use of Reclaimed Water for Power Plant Cooling, August 2007

17 Reclaimed Water & Public Power Public Power Examples Salt River Project, K-7 Plant, Tempe AZ Uses 3.1 MGD for cooling tower makeup water Glendale, CA: Greyson Plant Uses 0.3 MGD for cooling tower makeup water (uses tertiary treated water) Orlando, FL: Curtis Stanton Energy Center The 2 large, hyperbolic cooling towers at this power plant use over 8.0 MGD of reclaimed water to cool the plant s boilers. The plant receives its high-level disinfected reclaimed water from the Orange County Easterly domestic wastewater treatment facility in Orlando. Vero Beach, FL: Municipal Power Plant The Vero Beach wastewater treatment facility provides this power plant with 0.1 MGD of high-level disinfected reclaimed water for use in its cooling tower. Lakeland, FL: McIntosh Power Plant The 5.4 MGD of reclaimed water used for cooling purposes at this plant receives intermediate level disinfection from Lakeland s domestic wastewater treatment facility. Kissimmee, FL Utility Authority: Cane Island Plant Uses MGD for cooling tower makeup water. Two water reclamation plants combine reclaimed water into a long pipeline. Two separate power plants use portions of the water.

18 Energy for Water Peru Utilities, IN Peru, IN population 16,000 Has combined sewer system Upgrades to WWTP Abandoned primary clarifiers Converted aeration tanks to vertical loop reactors (VLRs) Turned anaerobic digesters to interchange rectors Results Increased capacity Better effluent quality Reduction of aeration energy cost by a factor of 3 Eliminated need for natural gas at utility by using a solid reductions system Reduced waste sludge disposal costs by a factor of 10

19 Key APPA Materials Link to free download of the Aspen (APPA) Natural Gas Study: Links to Series of Three Webinars on Switching Coal to Natural Gas: September 21, 2010, 2-3:30 pm EDT, Webinar 1: The Basics of Natural Gas for Base Load Energy Production October 7, 2010, 2-3:30 pm EDT, Webinar 2: Switching from Coal to Natural Gas: Buying Natural Gas, Nominations, and Balancing October 21, 2010, 2-3:30 pm EDT, Webinar 3: Switching from Coal to Natural Gas: Storage, Curtailment, Risk and Hedging To purchase printed version of Aspen Natural Gas Study, please contact Jeff Haas, or 202/ Link to availability of six APPA white papers on permitting, operating, and costs of geologic CCS for coal or natural gas (including water issues):

20 Contact / Questions J.P. Blackford Senior Environmental Services Engineer JPBlackford@APPAnet.org