Case Study: Zero Energy

Jennings Creek Elementary School

Warren County Public SchoolsBowling Green, Kentucky

The First Zero Energy Building Funded by a Performance Contract

CMTA is proud to partner with Warren County Public Schools on their second Zero Energy school and one of the most energy-efficient school in Kentucky. CMTA's innovative funding approach overcame possible financial barriers for the Warren County School Board. CMTA was thrilled to be a part of the design for this Zero Energy school in Warren County, ten years after the first Zero Energy school in the US was constructed.

The Challenges

  • Deliver a Zero Energy school on budget and on schedule
  • Create a funding source for solar panel installations
  • Coordinate designs and scheduling with a separate performance contract
  • Create a built learning environment that provides access to building operational information within the classroom
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I would highly recommend the CMTA team to any entity looking to be blown away, and that desires proven results. Created with Sketch.

Chris McIntyre

Chief Financial Officer - Warren County Public Schools

The Solutions

Warren County Public Schools' goals were established in 2010 with WCPS' Richardsville Elementary, the first Zero Energy public school in the nation. Jennings Creek Elementary School was designed to be the school district's second zero energy building, making it one of the most energy-efficient schools in the state of Kentucky.

To meet the client's project goals, CMTA contributed engineering design and commissioning for this elementary school, as well as implementing an energy savings performance contract for the project.

During the design process, highly efficient heat geoexchange heat pumps and dedicated outdoor air systems (DOAS) were designed to exceed code requirements regarding energy and indoor air pollutants. The building envelope is comprised of Insulated Concrete Forms (ICF), a super-insulated roof (R-32), and passive-improved windows. In addition, a green kitchen and ultra-efficient LED lighting design were included in the project.

With these strategies, the renewable energy system was designed to drastically offset the building's energy consumption. Using a Data-Driven Design, the facility's modeled energy consumption and solar production was compared to the 15-minute interval data for Richardsville Elementary School, utilizing CMTA's real-world data. This data was used to determine when the solar energy would offset building energy consumption versus being sold back to the utility. Utilizing this design method, the building's renewable energy solar array was sized to be a 330 kW photovoltaic roof-mounted system.

Jennings Creek Elementary School was designed to be an energy-efficient building that also prioritizes Occupant Health and Wellness. Zone sensors monitor temperature, humidity, and carbon dioxide levels to adjust the equipment's operating conditions, and bipolar ionization devices were installed on each item of equipment to improve indoor air quality.

Jennings Creek Elementary School has also been equipped with CMTA's occupant engagement dashboard, known as SPHERE. The immersive technology was created to inform building owners, students, and staff about the building's information and performance, while becoming a classroom teaching tool to mesh with WCPS' curriculum. The learning spaces included a "Maker Space" and group work stations to promote collaborative learning. Flexible seating options were also used to cater to different student learning styles.

SPHERE: An Interactive Learning Dashboard

SPHERE, CMTA's occupant engagement dashboard helps inform students and integrate curriculum daily. This version of SPHERE is entirely custom designed for Warren County Public Schools. It not only monitors and shows real-time energy use for Jennings Creek Elementary School, it is also integrated with all buildings across the entire district. The Interactive Learning Dashboard allows students to tour the school and learn about energy efficiency and the economic impact. Click here to see what SPHERE is all about.

The Results

Warren County Public Schools takes pride in being a progressive school district, especially when it comes to energy efficiency. According to Energy Star, the median elementary school's energy usage index (EUI) is 48.5. As of February 2020, Jennings Creek Elementary School operates at 15.0 EUI, representing an energy usage 69% below a typical facility, making it the most energy-efficient school in Kentucky and one of the most energy-efficient schools in the country.

The Data-Driven Design approach used to size the solar photovoltaic system resulted in a cost-efficient zero energy facility. Although it was not a part of the guaranteed savings, the net-meter solar design, combined with demand limiting control strategies, also offsets a portion of the facility's electrical demand charges. Jennings Creek ES's average monthly peak demand during a 30-minute period of time is 127 kW or 1.5 W/SF, which is approximately 25% less than similar facilities in the Warren County school district.

Jennings Creek Energy Consumption vs Production

What does this data mean?
Consumption: Energy used by the building
Production: Energy generated by the building