How IU measures campus energy

Story by Emily Beck
@emebeck1 |
Development by Anna Boone
@annamarieboone |

IU has five main meters measuring how much electricity buildings are using. They account for big chunks of the campus.

About three years ago, a project began to place a meter on every building. These cost between $500 and $8,000 depending on the building, and can automatically send data to the Service Plant. Right now all buildings on IU’s campus have a meter, said Hank Hewetson, the assistant vice president for facility operations, but not all have the automatic reading capabilities.

“Out of the hundreds of meters we have, maybe 30 we have to read manually,” he said.

The project is nearing completion — soon, utility workers will be able to track the energy each building uses in real time and see where they can make improvements. They’ll also use this information for billing purposes, and to account for energy usage in their annual report.

The University wants to develop a profile of each building for each utility, Hewetson said.

“We want to go back and build a comparison of historical data, so that we can see the change in the building,” he said.

With the data, they’ll have a baseline to measure against, so they can see if their methods are working, and a building has become more energy efficient over time. Each building on campus uses energy in different ways – none are cookie-cutter. Because of this variability, Utilities looks at energy density, or kWh per square foot.

Once these profiles are established, it will be easier to pinpoint inefficiencies and fix them.

This project will help utility workers know where to spend their time making improvements to buildings. Fixes could become quicker, buildings could become more efficient, and the campus could burn fewer kWhs, which will save the university, and ultimately the students, money.

“If we’re just looking at 20 buildings on one big meter, we don’t know where to go,” Hewetson said. “You can’t manage what you can’t measure.”

The data from those five main meters appear as a shaky line on a chart on a television monitor at IU’s Physical Plant — a big picture of the campus.

The station is manned 24/7 by at least one worker, keeping an eye on the chart’s progression throughout the day among other things. They watch the campus wake up and go to sleep every day, visible through the peaks that mean people are watching television and turning on lamps and the valleys that mean lights are going off and laptops are unplugging.

The UIG distributes all utilities – electric power, water, steam, natural gas – through about 449 miles of systems. But that number will increase next year with the addition of the new informatics building, among other projects

IU pays an average of 8.5 cents per kilowatt hour. A number of different charges contribute to that number. Hewetson called it the “blended cost.”

Four of those cents is standard — charged every month for each kWh. But the other 4.5 comes from the peak time of consumption.

The peak time is the highest consuming two hour window of the month. Hewetson said it’s usually between 2 and 5 p.m. In that time, IU pays about $24 for each kWh it uses.

This charge isn’t lumped together, though — the peak cost is split up and added on to that standard charge for each kWh. That’s why it’s called a blended cost, and that’s how it shows up on the energy bill.

Say the University’s peak usage is 30 megawatts in two hours. That comes to $720,000. That’s about $24,000 per megawatt during peak.

“If we can control that, if we can save one megawatt, that’s $24,000 we’ve avoided cost for that month,” Hank said.

Utilities keeps an eye on the peak, and when they think they’ll reach it that day, they send out an email to IU offices encouraging people to use less energy.

Electricity costs rise every year, so IU must continue reducing how much energy it uses in order to stay in the same place and avoid higher bills.

In 2011, the campus was consuming 19 kilowatts of energy per square foot every hour. During the 2010-11 school year, campus used about 289,426,000 kWh, up from about 282 million the year before, Hewetson said. The energy bill had climbed to $21 million. That was too much — and the campus was growing, adding more buildings and students.

Consumption was projected to keep increasing.

So the building maintenance crew started doing “proactive maintenance,” Hewetson said. The team replaced old, outdated lights with more energy-efficient ones. They cleaned and replaced parts of buildings and adopted better design standards for energy efficiency.

“We have a mission to fix things before they become a problem,” he said.

In 2015, energy usage dropped to 276,843,000 kWh. Despite the bend downward, the bill was the same as it had been in 2011. Hewetson said the building maintenance crew intends to continue retrofitting buildings and moving toward increased sustainability.

“It’s not one thing. It’s a dozen or more things,” Hewetson said.