Case Study: Performance Contracting

Warren County Public Schools

Warren County Public SchoolsBowling Green, Kentucky

The Most Energy Efficient School District in Kentucky

Located in Bowling Green, Kentucky’s fastest growing city, Warren County is the fourth largest school district in the state. CMTA is proud to continue our 30+ year partnership with Warren County Public Schools by making improvements across 2,350,000 square feet of instructional space in 28 buildings. CMTA accomplished all of Warren County’s ambitious goals for their school district, including renovating the HVAC systems in six schools.

The Challenges

  • Improve thermal comfort, indoor air quality and equipment reliability throughout their aging facilities
  • Substantially reduce energy and operational expenses to help fund the needed upgrades
  • Deliver savings in a school district that is already ranked the 16th most energy efficient school district in the state
  • Completely renovate 6 schools during the district’s 9-week summer break
  • Expand the districts solar photovoltaic array installations and provide the district with a second Zero Energy school
  • Create a built learning environment that provides access to building operational information within the classroom
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CMTA’s guaranteed energy savings division, in my opinion, is second to none. Of all the projects I have been involved in at WCPS, this has by far been the smoothest and most rewarding. Created with Sketch.

Chris McIntyre, Chief Financial Officer

Warren County Public Schools, Bowling Green, Kentucky

The Solutions

Warren County Public School’s mission in regards to energy consumption in their buildings is to raise awareness to energy issues, create and maintain a comfortable environment for the students and employees and promote energy saving practices. This mission of sustainability is why the first Zero Energy school in the United States, Richardsville Elementary, was built in Warren County in 2010. Prior to this project, Warren County Public Schools was ranked the 16th most energy efficient school district in the state. Warren County Public School’s goal for this project was to expand the energy and cost-efficient measures to their existing, aging facilities and renovate these facilities without relocating students or staff, while also preserving monetary funding for new schools.

Warren County Public School partnered with CMTA to renovate 654,000 square feet of HVAC equipment across six schools within a 9-week summer break. Five of those facilities were converted to geothermal heat pump systems, eliminating inefficient chillers and boilers that had become expensive to maintain. Existing indoor air quality issues were discovered to be from areas getting no outside air while others were getting too much - causing humidity issues. Our Occupancy Health and Wellness principle was used to improve indoor air quality issues by installing dedicated outdoor air systems coupled with individual heat pumps. Carbon dioxide and humidity sensors were installed to monitor the indoor air quality. In addition, all existing ductwork was cleaned, internally insulated ductwork encapsulated and bi-polar ionization devices installed.

Over 23,000 light fixtures were converted to LED technology and 1,504 plumbing fixtures were converted to low flow across the school district. Athletic fields previously irrigated on water meters with sewer charges received new dedicated irrigation meters. A web-based HVAC control system was installed in 20 buildings to efficiently control and monitor the new and existing equipment. To reduce peak kW demand charges, a revenue-grade power meter was installed on each building to monitor power consumption and relax temperature setpoints based on monthly KW limits. Optimum start algorithms bring the building out of setback while operating equipment on the first stage, where efficiencies are the highest. 

A detailed analysis of existing utility charges and electrical infrastructure at several facilities uncovered the potential for significant savings with minimal modifications. KW demand charges were reduced by downsizing building transformers, combining multiple electrical services to take advantage of demand diversities at two high schools, and a dedicated athletic field lighting meter was installed at a third high school.

Other project improvements included a roof replacement at Warren Elementary School, window replacements at three schools and a new Aquatic Center dehumidification unit that enters an energy saving mode after the new automatic pool cover is closed.

An Interactive Educational Dashboard

To further promote energy saving practices, the energy and educational dashboard, “Sphere” was developed to highlight the improvements made within this project. The dashboard includes 360-degree views of mechanical rooms before and after the project was completed to educate users – specifically regarding the improvements made (with infographics) explaining how the new energy-efficient equipment operates. Utility bill information is uploaded monthly so that users can compare their consumption to the building’s baseline or target energy goals, providing a tool to incentivize a reduction in energy consumption.

The Results

Using the Performance Contracting approach, Warren County Public Schools made significant improvements throughout all of their facilities with energy savings guaranteed by CMTA. The total cost savings achieved during the first year totaled $1,215,155, resulting in $372,402 in excess savings beyond the guarantee - all of which was retained by the school district. These savings ultimately reduced WCPS's electric, gas and water consumption, as well as improved the learning environments for students and faculty. This cost-effective approach also preserved capital funds for new construction projects in this growing school district. 

Prior to the Performance Contract, Warren County Public Schools initially operated at a district wide EUI of 40.8. The EUI for each facility and the district as a whole is being tracked via the energy and educational dashboard, “Sphere." This teaching tool is meant to inspire students by demonstrating how certain choices impact the environment. The most recent district wide EUI has dropped to 25.0, representing an energy usage decrease of 38%, making Warren County Public Schools the most energy efficient school district in the state.

Warren County Public Schools Energy Use

What does this data mean?
Baseline: The annual energy consumption before the project
Guaranteed: CMTA's guaranteed energy use for the client post-project
Actual: The measured energy use after the project