Iowa State tries to power campus sustainably

Jonathan Findlay

As the frigid Iowa winter winds pierce through ISU students’ heavy coats, they probably aren’t thinking about how that same wind helps provide power to the ISU campus. 

Relief comes quickly as students hustle into a warm building, without a thought as to the source of where that warmth comes, but just grateful to feel their faces again. 

Where, then, does this warmth come from? All the heating, cooling and electricity on campus is provided by the power plant on the east end of campus. In fact, half of the energy used on campus is in the form of steam for heating, said Jeff Witt, the power plant’s utilities director.

Using steam to provide energy for campus gives flexibility. Steam can be used to drive turbines for electricity production then reused to heat buildings. Steam can also be used to cool buildings by running the compressors that cool the air in campus buildings.

This dual-use process is known as cogeneration and would run at 33 to 35 percent efficiency in a conventional power plant. Iowa State’s power plant, however, runs this process at 60 percent efficiency.

Energy conservation efforts on campus and improved efficiency using the cogeneration process combined helped cause an 8 percent drop in campus energy usage, from roughly 3.8 million British thermal units, or 4 billion joules in 2008 to 3.5 million British thermal units, or 3.7 billion joules last year.

The same cold wind that drives people indoors also drives the windmill located just north of the power plant. This windmill, along with the electricity purchased from four other windmills in Northeast Story County, provide a little more than 7 percent of Iowa State’s electricity needs.

Sustainable electrical production is still a new and expensive field compared to established methods like burning fossil fuels. The use of fossil fuels may not be sustainable, but Iowa State is making strides in different ways to lessen its carbon footprint and become more sustainable. For example, Iowa State uses more than 50 solar-powered trash compactors on campus that reduce garbage pickup from once per day to once per week.

Iowa State collects waste from these compactors and from other receptacles on campus and sends the waste to a few different waste facilities, including the Ames Resource Recovery Center. The Resource Recovery Center follows the Environmental Protection Agency waste hierarchy to reuse, recycle, compost, burn and convert waste into useful energy or sent to a landfill.

The hierarchy puts reusing and source reduction at the most desirable form of waste management, recycling and composting next, followed by energy recovery and finally treatment and disposal as the least desirable form. 

About 70 percent of Iowa State’s waste is disposed of in this way, said Merry Rankin, Iowa State’s director of sustainability.

The energy created by burning waste “reduces the city of Ames’ coal use by about 10 percent,” Rankin said.

Many programs have been created following this waste hierarchy. One, called ISU Surplus, allows for the sale and reuse of excess equipment either between departments or to the public.

Iowa State has its own composting site. Concrete from demolished buildings is largely recycled.

In the past, energy costs for the entire campus were determined each month and individual buildings were billed for energy use based on size. Now, each building is metered and billed separately based on its actual energy use. 

Recently, the Live Green! loan fund was created to promote energy conservation and sustainability. Individual buildings can take this loan and use the money to implement sustainable infrastructure and use the money saved each year to repay the loan.

After repayment, the building continues to receive the benefit of lower costs from energy savings. Programs like this are part of the reason Iowa State has seen a reduction in overall energy usage.