Where’s the Dirt?
Electricity looks pretty clean, right? You flip a switch and a light goes on. What’s so messy about that? Well, it’s the making of electricity that can create pollution. About 15 percent of TVA’s power is generated by the burning of coal. When coal burns, potentially dangerous chemicals like sulfur dioxide (SO2) and nitrogen oxides (NOx) are released into the air. (Read information from the U.S. Environmental Protection Agency about air quality.)
TVA uses air-cleaning equipment at it's coal plants to help keep air clean. And because TVA's emphasis has moved away from coal generation and toward cleaner forms of making electricity, today the power we deliver is 62 percent carbon-free.
Clearing the Air
To clean up the air while still providing everyone in the Tennessee Valley with electric power, TVA uses some pretty complex, expensive equipment.
So far TVA has spent around $6 billion to control the release, or “emission,” of chemicals from its coal-burning power plants. Here’s what it’s doing:
- TVA has put “scrubbers” on 60 percent of its coal-fired capacity. These scrubbers help clean up SO2. In addition, TVA has switched to low-sulfur coal at some of its fossil plants. As a result, sulfur dioxide emissions have been reduced by 94 percent since 1977.
- The best weapon against NOx is something called a selective catalytic reduction system, or SCR. TVA has installed SCRs on 21 of its coal-fired units. As a result, emissions of nitrogen oxides have been reduced by 91 percent since 1995.
Making electricity is a bit like creating a huge science project for school. You get all these materials together and mix them up to make something incredible, and then your mom gets on you to clean up the mess you’ve made in the kitchen.
You can’t make anything—a science project, a cake or electric power—without having to clean up afterward. For TVA that means finding ways to make power for millions of homes, schools, farms and businesses, and at the same time keep the environment clean and healthy.