Tennessee School Districts

Fast Facts

Industry: Education
Location: Knox and Williamson Counties, TN
Program: TVA-EnerNOC Demand Response Program
DR Strategy: Curtailment only
Primary Curtailment Strategy: Temporary adjustment of HVAC setpoints and lighting
Annual Payments:
Approximately $70,000 (Knox County Schools)
Approximately $45,000 (Williamson County Schools)

The Big Picture

EnerNOC offers compelling benefits to school districts trying to reduce costs with smarter energy management. With EnerNOC's energy intelligence software (EIS), schools can earn regular payments through demand response programs and reduce energy costs—benefiting the schools and ultimately, local ratepayers. EnerNOC's EIS helps school districts to protect the local energy grid during times of peak use while doing their part to protect the environment. And it provides new insights on energy use that can lead to further savings by shining a spotlight on energy waste and giving facilities teams the information they need to prioritize appropriately.

Knox County Schools in Knoxville, TN, Williamson County Schools in Franklin, TN, and other Tennessee school districts served by the Tennessee Valley Authority (TVA) joined the TVA-EnerNOC Demand Response program. These major school districts were attracted by the significant payments for participation, as well as by the opportunity to support and protect their communities. After partnering with EnerNOC for several years, these districts have found that demand response helps their bottom line without affecting operations or the educational experience.

During demand response dispatches, these schools reduce their energy by adjusting their HVAC setpoints, shutting off unnecessary lighting, and making other temporary changes. Since dispatches often occur in the early afternoon on the hottest or coldest days of the year, school buildings are often unoccupied, so impact is minimal. In addition to significant payments, these schools also benefit from the visibility they get from EnerNOC's software, which helps identify new opportunities for reducing energy use.

Using Demand Response to Cut Energy Costs

School districts comprise diverse facilities of varying age and efficiency, which add up to significant amounts of space—and major energy bills. For example, Knox County Schools, one of the largest districts in the state, includes 88 schools totaling more than 9.5 million square feet, while Williamson County Schools has 42 buildings totaling more than 5 million square feet.

“When I started the energy management department in 2007, our district-wide energy costs totaled more than $16.25 million annually,” recalls Knox County Schools Energy Manager Zane Foraker. “Energy was the largest expense after personnel and we were facing unsustainable cost increases.”

The need to reduce energy costs is a common theme across all school districts. The Williamson County School district had already implemented an aggressive and dynamic energy program, including equipment and systems changes aimed at increasing efficiency. But it was always looking for new ways to save.

For Knox County, Williamson County, and other participating Tennessee districts, the TVA-EnerNOC Demand Response Program offers an extremely attractive opportunity to reduce energy costs. This major, phased program involves a 10-year arrangement with EnerNOC that will ultimately involve 1,000 energy customers (including schools, businesses, manufacturing facilities, and more) and remove 560 megawatts (MW) of demand from the regional power grid during peak usage periods.

“We heard about the program from TVA and were very interested right from the start,” says Foraker. “We can’t negotiate our rates, but we can take a more active role in reducing our energy use, fostering energy efficient behaviors among our staff and students, and doing whatever we can to reduce our energy bills,” he says. “The TVA-EnerNOC Demand Response Program lets us do all that and more.”

The Williamson County Schools team agrees. Williamson County Schools leaders also found that EnerNOC demand response offered significant advantages, including the ability to monitor demand on a real-time basis. Armed with this information, the school can make changes that lower demand and costs—during demand response dispatches and beyond.

Both districts took an incremental approach to DR, beginning with careful assessment of their facilities by EnerNOC. The districts began with their most efficient and modern schools, since these building had the automatic controls (e.g., up-to-date controls and building management systems) and the capacity to curtail approximately 200 kilowatts (kW) when necessary.

For example, Knox County started with four schools in a 2008 pilot, but now has more than 20 schools participating, and ultimately envisions enrolling 72 schools. Williamson County started with 10 schools in 2009, and has added 18 additional schools. More than half of its facilities now participate in the program.

During dispatches, each school makes temporary changes, such as raising the cooling setpoint from 72 degrees to 80. “We’ve found that most of our schools only rise about 1.5 degrees an hour even on the hottest days, so it’s not really noticeable,” says Foraker.

"By the time anyone notices any change, school is often out for the day." During the summer months, dispatches can last from 4 – 6 hours, with the earliest start time of 1 p.m. Schools respond within a 30-minute time period. In most cases, the dispatches happen when facilities are already cycling down, so making changes to lighting and setpoints aren’t critical.

While Knox County implements the changes on a school-by-school basis, Williamson County makes the changes centrally via its Novar building management systems. In fact, key personnel can respond to dispatch requests via laptop—customizing the response based on current utilization of district-wide facilities.

Knox County does not inform staff and students when a dispatch is underway. “If you don’t tell people, they don’t notice the changes,” says Foraker. “Although sometimes we’ll contact a specific school and ask them to curtail more, when needed.” Williamson County takes a different approach, informing schools but allowing them to override the changes if they have to. In this way, schools retain control and can make thermostat adjustments if absolutely necessary.

During implementation, EnerNOC engineers installed customized interval metering and monitoring equipment, giving each school access to real-time intelligence on energy use. By logging into EnerNOC, facilities personnel can monitor their performance during a DR dispatch and beyond. 

Key personnel log in regularly, during dispatches and to monitor ongoing energy use. The cloud-based software puts a lot of information at their fingertips. And it makes the information easy to visualize and interpret—so they can see how changes affect energy use at specific schools.

The Results

By adjusting their cooling/heating, lighting, and making other temporary changes, each school in the TVA-EnerNOC DR Program can reduce its energy use by 150 to more than 300 kW. Aggregated across the district, these reductions are significant. For example, Williamson County’s curtailment target is 1,525 kW, which it has even exceeded during DR dispatches.

These reductions earn the districts much-needed payments directly from EnerNOC. Williamson County earns more than $45,000 annually while Knox County Schools receives approximately $70,000. Both districts expect these figures will rise as more schools in their district join the TVA-EnerNOC program.

After several years, the impact is clear at both districts. “EnerNOC earns us unbudgeted revenue that we can invest in other programs,” says Foraker. “And the software that we get from EnerNOC is a really strong tool that lets us achieve even more efficiency and savings on an ongoing basis.” Thanks to this program, other energy reduction efforts, and vigilant energy management Foraker has reduced his district’s annual bill by more than $2 million a year.

The results at Williamson County are equally impressive. Payments that the school earns from the TVA-EnerNOC program—about $90,000 to date—contribute to the general operating funds. These revenues can be used to fund other initiatives that contribute to the overall quality of education across the county.

The Benefits

Addressing rising energy costs is the key benefit that EnerNOC delivers to these districts and others who participate in the TVA-EnerNOC program. EnerNOC delivers significant payments, as well as new insights on energy use that enable even more savings. While the financial impact of the program is critical to cost-conscious schools, they also receive other benefits from partnering with EnerNOC, including:

More Energy Knowledge

In the past, these districts did not have precise energy use figures—just a monthly bill. Now, with EnerNOC's software, they know exactly what their use is, knowledge that they can apply in many ways. Now the districts can make changes and see the impact on energy use almost immediately.

Educational Opportunities

The insights provided by EnerNOC provide new opportunities for environmental service learning at Williamson County Schools. EnerNOC data is used in the classroom as part of the high school curriculum. Students can study actual energy use on a day-by-day basis, providing a real-world window on the impact and importance of energy efficiency. The Knox County Schools use some of the payments from EnerNOC to fund an energy-awareness training program in its middle schools.

Greater Control Over Facility Costs

Schools often serve as community hubs, providing facilities for meetings and other events. In the past, the exact cost of using a facility wasn’t clear. “Now we can see exactly when our facilities are in use, and how much various events cost,” says Foraker. “Knowing the real costs lets us get reimbursed for the use of our buildings—without any guessing.”

Low Impact

Both districts highlight how simple it was to join the TVA-EnerNOC program initially, and how EnerNOC streamlines ongoing participation by taking the work out of demand response. They found that participating in the TVA-EnerNOC DR program was very simple for their time-strapped organizations. And both districts were clear that demand response had no impact on the educational environment.

The Future

Both districts are continuing to evaluate their facilities and add schools to the TVA-EnerNOC program when their curtailment capacity makes them viable candidates. They’re using the knowledge gained from the program when designing new facilities. And they’re spreading the word about the program via state-wide professional organizations and other channels.