Generation and Impact: A Tale of Three Cities

Posted April 22, 2019

by Erin LaVoie

When you flip the switch, the lights come on. That’s about the extent most people think about electricity in their daily lives. This Earth Day, I want to reflect on how our power is generated in each of ILLUME’s main offices—Madison, Portland, and Tucson—and how it affects the environment and communities upstream and down. 


The Midwest has historically been very reliant on fossil fuels for generation, and Madison is no exception. Madison Gas and Electric (MGE) is quickly growing the share of renewables in the mix, but coal is still dominant at 48% as of 2016, with purchased power making up 21% and natural gas and oil making up 19%.2

The effects of mining and burning coal for electricity in Southern Wisconsin spread far beyond its borders. In Montana and Wyoming, where much of the coal is mined, wells go dry and water needed for drinking, ranching, and irrigation has high salinity. The mining process changes how groundwater flows, and releases salt by exposing new rock and pumping out saline groundwater. 3 Near coal burning power plants in Wisconsin, such as Elm Road where MGE is a minority owner, coal dust permeates the air and covers houses, cars, and playgrounds. Testing by the Sierra Club of nearby streams, marshes, and culverts in 2018 found high levels of aluminum, copper, lead, arsenic, manganese, boron, and cadmium. Charlie Michna, who lives next to two coal power plants, said in a recent article: 4 

 “You can’t put up this much black air and not have it have an effect on you.” 

MGE has grown renewable capacity and reduced carbon emissions by 20% from 2005 through 2016.5 With community support and engagement, they are quickly working toward their goal to supply 30% of electricity with renewable resources by 2030 and reduce carbon emissions by 40% from 2005 levels by 2030.6 These efforts are a reminder that even historically coal-dependent states can help combat global climate change and local pollution.


Portland gets the majority of its electricity from coal and natural gas (combined 43%) with purchased power (33%) and hydropower (15%) as other significant slices of the pie.7 Hydropower’s emission-free status means that Portland has one of the cleaner energy generation mixes in the U.S., but that does not mean it doesn’t have an impact. Dams cause degradation to rivers and fish populations. A small example of a region-wide problem, the effect on water quality from Portland General Electric’s (PGE) Pelton Round Butte dam on the Deschutes River is harming the local economy of Maupin, which relies on tourists and anglers. John Smeraglio, owner of a local fly fishing store, notes:8

“The most important thing about this area is the Deschutes. It is having a huge economic impact. More than people realize.”

PGE is working toward supplying 50% of its electricity from renewable sources by 2040 and growing wind and solar capacity with support from Portlanders.9 More than 200,000 PGE customers now buy local renewable power.10 PGE is also lessening the impact of dams on the environment by upgrading the seven they either fully or partially own to protect migratory fish.


You may be surprised to hear that in sunny Tucson, 69% of electricity comes from coal with natural gas and renewables tied for second largest source at 11%. Tucson Electric Power’s (TEP) planned generation mix for 2023 is 78% fossil fuels, largely driven by the conversion from coal to natural gas, and 19% renewable energy.11

TEP’s coal and natural gas plants mainly run on groundwater though Tucson is at-risk for groundwater depletion.12 Tucson relies on the Colorado River, which is now only half-full. Nearby Lake Powell is half-empty, the reservoirs of Roosevelt Lake and the Salt and Verde rivers are dwindling, and Lake Mead has shrunk to its lowest level.13

Tucsonans have lowered their water use and aquifers are on the mend. In addition, Tucson residents have stepped up and installed solar PV which uses very little water. At the same time, TEP has long offered time varying rates to help shift load away from peak times of the day.

The Future

Most people serious about mitigating climate change agree movement toward zero-carbon fuels is necessary. It is critical to remember that to do so requires a change in how and when we use electricity in the near-term. All sources of generation have impacts—from turbines that interfere with bat migration to solar that requires mining of rare earth metals. This Earth Day, let’s think about the future and reflect on the past, learning lessons about how generation affects our communities and the environment and putting those in focus as we come up with better solutions. Our local utilities can’t do it all themselves, it will take community engagement and a huge collective effort to conserve energy, shift our usage patterns, and grow our share of renewables. As Director of Yale’s Center for Green Chemistry and Green Engineering Paul Anastas says, “We’re all in the same boat, and we only have one boat.” 

1 MGE’s Electricity Sources, Madison Gas and Electric, Accessed April 17, 2019,; Where Your Electricity Comes From, Portland General Electric, Accessed April 18, 2019,; 2018 Action Plan Update, Tucson Electric Power, April 30, 2018. Accessed April 17, 2019,

2 Madison Gas and Electric, MGE’s Electricity Sources

3 Tim Vernimmen, Freshwater is Getting Saltier, Threatening People and Wildlife, Scientific American, December 6, 2018, Accessed April 19, 2019.

4 Joe Tarr, Killer Coal, Isthmus, March 7, 2019, Accessed April 17, 2019,

5 Environmental and Sustainability Report, Madison Gas and Electric, Accessed April 19, 2019,

6 Madison Gas and Electric, MGE’s Electricity Sources

7 Where Your Electricity Comes From, Portland General Electric.

8 Kim Moore, A damaged river imperils a central Oregon town, Oregon Business, April 4, 2018, Accessed April 17, 2019,

9 Where Your Electricity Comes From, Portland General Electric. 

10 Green Future Products, Portland General Electric, Accessed April 19, 2019,

11 Tucson Electric Power, 2018 Action Plan Update

12 Nancy LaPlace, Tucson Electric Power: Ignoring Water, Climate Change Risks, Energy and Policy Institute, June 16, 2017, Accessed April 18, 2019,

13 Caitlin McGlade, Parched: Arizona’s shrinking aquifers, The Republic, March 24, 2015, Updated December 14, 2016, Accessed April 18, 2019,