Where does Rapid City’s electricity come from?

Though the Black Hills are close in proximity to Wyoming’s coal mines, water generates a surprising quantity of Rapid City’s electricity.

By Bryce King

We use electricity every day. Making our coffee and toast, washing our clothes, cleaning the dishes, cooling our home, lighting our room, and even reading this article all require it. However, we don’t think about where our energy comes from until our power goes out during a blizzard or thunderstorm. So, where does it come from?

The state of South Dakota is powered by six utility companies. These six companies give electric power to specific areas of South Dakota and are regulated by the Public Utilities Commission. Black Hills Power is the company that provides energy for Rapid City, but our power may come from beyond Rapid City, perhaps even hundreds of miles away.

According to a recent study by the Institute for Electric Research, 60% of South Dakota’s energy comes from hydroelectricity, which is the production of energy by falling or flowing water. Hydroelectricity is very efficient, cost effective, and convenient, because it can respond quickly to the rise and fall of demand. Hydroelectric plants also don’t produce any direct waste, making them safer for the surrounding environment. South Dakota’s largest hydroelectric dam is the Oahe Dam on the Missouri River. Not only is it a popular fishing spot in Pierre, but it is also is the fourth largest artificial reservoir in the United States, providing electricity for many of the northern states including North Dakota, South Dakota, Montana, Minnesota, and Nebraska.

The endless number of poles and wires that you see along the highway, in front of your house, and around town are part of the Electrical Transmission and Distribution System, also called the “power grid.” Power plants nationwide are connected through the power grid, which means if one plant can’t produce enough electricity for certain areas, other power plants can send energy, like a series circuit. Rapid City is an ideal location in the electricity realm,  placed directly on the boundary of the Western and the Eastern power grids. Even though Rapid City is powered by the Oahe Dam and other smaller power plants along the river, it is one of the points where the two national power grids connect. This means it can switch its power from the hydroelectric plants along the Missouri to the large coal fields and power plants of Wyoming’s Powder River Basin, if needed.

Rapid City used to have its own coal power plant a few years back, but due to federal regulations it and many other coal powered plants in the upper midwest region were forced to shut down. Terminating these plants meant electricity needed to be imported from greater distances, triggering higher prices over the last several years.

Most people are likely familiar with the various steps in moving electricity from a power source to our homes but did not realize it. The following slideshow tracks electricity from the hydroelectric plant to a typical outlet.

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Banner image: “High Wire Desert Crossing” by edward musiak on Flickr