While closing coal-fired power plants is often lauded for improving air quality, it’s also saving billions of gallons of water a year from being withdrawn from the Great Lakes and local resources.
Last month, Jackson-based Consumers Energy pledged to save another billion gallons of water over the next five years beyond the savings seen by closing seven coal plants in 2016. While the goal is part of the company’s broader clean energy and environmental pledge over the next two decades, it also highlights an overlooked aspect of the energy sector: The industry is a major consumer of water.
Water plays a key role in energy production by cooling equipment at coal, natural gas, waste-to-energy or nuclear plants. While newer plants powered with turbines are more water-efficient than old coal plants, the rapid growth in oil and gas production through hydraulic fracturing also has a high demand for water.
Although 1 billion gallons over five years is just a fraction of Consumers’ overall water consumption, advocates say it signals an important shift in considering water use in energy. This is broadly referred to as the water-energy nexus.
“It really is significant that one of the largest electrical companies in the state is taking this initiative and underscoring this connection between water and energy,” said Liz Kirkwood, an environmental attorney and executive director of Traverse City-based For Love of Water (FLOW). “With the extraction, production and transportation of all energy, the impact on both the quantity and quality of water is significant. It’s something that really goes under the radar from the public’s minds.”
Consumers’ largest source of water use is to cool steam in the electric generation process, said Linda Hilbert, the utility’s executive director of environmental and laboratory services. The cooling process is considered a “non-consumptive use,” which means the water is used as a pass-through for cooling and returned back to the system.
OFF COAL, SAVING WATER
The 1-billion-gallon reduction will mostly affect Consumers’ gas operations, Hilbert added. But it also aligns with in-house goals over the past five years to reduce its water consumption. Last year, Consumers’ water use decreased 35 percent, largely as a result of the company closing its “classic seven” coal plants in 2016.
“That equates to about 200 billion gallons of water a year we’re not using compared to 2012,” Hilbert said. “That’s a big number.”
Coal plants use a significantly greater amount of water per megawatt hour (MWh) than gas plants. According to Consumers, the water intensity for coal plants is 29,631 gallons per MWh of generation. For a gas plant, it’s 233 gallons per MWh.
Water is still a key piece of the gas-extraction process through hydraulic fracturing and then piping it away, as well as moving coal ash byproduct to storage areas. Hilbert said reducing water consumption at these two points of the process will play a key role in meeting the 1 billion gallon goal.
Retiring the James De Young coal plant in Holland will also save the Holland Board of Public Works 11 billion gallons per year. Last year, BPW opened the Holland Energy Park natural gas plant to replace the De Young plant on Lake Macatawa.
The De Young plant was mostly supplied by Lake Macatawa for “once-through” cooling. The new plant uses an efficient “closed loop cooling water system.”
“This closed loop system allows water to be used for multiple cycles prior to discharge,” said BPW Operations Director Joel Davenport. “Additionally, the cooling tower utilized in the closed loop system is equipped with a plumber abatement system that has the added benefit of reducing the evaporative water loss via the plume.”
Compared to the 11.1 billion gallons that was withdrawn annually from Lake Macatawa, Holland’s new gas plant uses about 150 million gallons per year.
WATER USE AND CLEAN ENERGY
The water to support electric generation in Michigan comes from a variety of sources: the Great Lakes, nearby lakes or rivers, as well as groundwater or city water.
According to a report compiled by the Great Lakes Commission using water reporting data, Michigan’s total withdrawal from the Great Lakes basin in 2016 was over 9 billion gallons per day, a 7-percent decrease from 2015. Thermoelectric power production — or once-through and recirculated cooling — accounted for 74 percent of that. Consumptive uses of water — with irrigation making up the largest share — totaled 585 million gallons per day.
In addition to its 1-billion-gallon goal, Consumers also pledged to meet 40 percent of its energy needs with renewable sources by 2040, as well as retire all of its coal generation in that time.
FLOW officials said an overlooked benefit of switching to renewable energy sources such as wind and solar is the water savings.
“What Consumers did is commendable,” said Dave Dempsey, senior adviser at FLOW. “What we need to do as an environmental community is build on the case of clean energy and going beyond climate benefits and looking at water benefits.”
Dempsey has authored multiple books on the Great Lakes and was an environmental policy adviser to former Gov. James Blanchard.
“Clean energy is not just good for our air, but good for water,” he said. “It reduces thermal discharges, fish kills, mercury and withdrawal amounts.”
Dempsey said it’s also unlikely that state lawmakers would favor regulations that put stricter limits on water consumption in the energy sector.
“Probably the best hope to reduce water use in the energy sector is exactly what Consumers is talking about — moving past fossil fuels,” he said.
BUSINESS CASE FOR CONSERVATION
Darwin Baas, director of the Kent County Department of Public Works, says the county has been increasingly looking at water use related to its waste-to-energy facility, which relies on potable water from the city of Grand Rapids as well as water from the Grand River. In 2017, the facility used 112 million gallons. Water from the river is treated before it’s used for cooling and again before it’s discharged back into the river.
Water usage “is certainly a cost to us,” Baas said. “Over the past year or so, we’ve been asking the same question: How can we reduce that usage? Anytime you’re generating electricity — turning a turbine with steam or hot water — no question, you’re using a lot of water and it has an impact. It’s something most of us don’t think about.”
FLOW’s Kirkwood said Consumers’ pledge is similar to shifts from other companies in adopting environmental goals or demanding their operations be powered by renewable energy, as is the case with General Motors and Switch Ltd., a data center operator in Gaines Township south of Grand Rapids.
“They recognize that it’s important for the future of their operations — in their business context or in terms of attracting new business — to protect the resources and high quality of life so many communities are known for in Michigan,” Kirkwood said.
Last month, Consumers officials described the company’s plans for energy and water as a “long-term strategic commitment to protect the planet.”
“Water is one of the greatest natural resources Michigan has,” Consumers’ Hilbert said. “It’s really important we continue to focus on that.”