Advanced Energy Perspectives

Water, the West, and the Clean Power Plan

Written by Tom Plant | May 28, 2015 4:07:38 PM

This photo of the Hoover Dam intake towers was taken by Raquel Baranow in 2014. Water elevation on that day at noon: 1086.39 ft.

As the saying goes, in the West, the whiskey’s for drinking and the water’s for fighting. While much of the attention related to EPA’s Clean Power Plan is focused, appropriately, on the emissions and economic benefits of the new standards, a report just released by the CNA Corporation identified another benefit that may end up being worth more than all the other impacts combined: water.

The dams that hold the lifeblood of agriculture and the economy for most western states are now running at record lows. Last summer, Lake Mead, which supplies water for Arizona, Nevada, and California, fell to a level not seen since the dam was first filling in 1930 – 1,081 feet. Low levels of reservoir water threaten supplies throughout the west, but these dams also host large hydro-electric facilities. As the water level declines, so does generating capacity. Last summer, the dam was producing electricity at a level 23% below average. Under 950 feet, Lake Mead’s generators can’t produce power at all.

 No matter how you look at it, energy is a water intensive business. Thermal power plants need massive amounts of water for cooling. In Texas, the focus of the CNA report, during the most intense period of the recent drought, demand for water by energy sources rose 9% while the state’s reservoirs were at less than 50% of their capacity. Public utility commissions in western states are now beginning to consider the water intensity of resource plans as well as cost when evaluating utility proposals for new generation.

The CNA report evaluates the water consumption of the resources that make up Texas’s electricity generation and finds the following: 

FUEL TYPE

WATER CONSUMPTION

(gal/MWh)

Natural Gas Combined Cycle

198

Nuclear

672

Coal

471

Coal with Carbon Capture

846

Solar

28

Wind

--

Energy Efficiency

--

While the CNA report looked specifically at Texas, the findings could be applicable all across the West. The report found that water consumption from energy generation is projected to decrease in Texas over the period covered by the Clean Power Plan (2012-2029) by just 5% under a “business as usual” case. With the Clean Power Plan driving a shift in the resource mix, water consumption would decrease 21% – saving 66,000 acre feet/year. That’s enough water to fill the Cowboy stadium 37 times.

These water savings come from demand side energy management (reducing the need for electricity generation), renewable generation (needing no water for cooling), and replacing coal-fired generation with natural gas, which uses less than half the water of coal.

Finally, the CNA report found that while costs per unit of energy would increase over the 2012-2029 period by 5% the overall energy system costs would decrease by 2%. 

While the EPA and much of the world is looking at the emissions impact of the Clean Power Plan, Western states may see the EPA plan as one way to deal with the water shortages that threaten their economic future.

Learn more about AEE's engagement with EPA's Clean Power Plan: