Case Study: Zero Energy

Jennings Creek Elementary School

Bowling Green, KentuckyWarren County Public Schools

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 the most energy-efficient school in Kentucky. CMTA's innovative funding approach overcame the Zero Energy project's barriers for the Warren County School Board. CMTA is thrilled to announce 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 was designed to be the school district's second zero energy building. The building is now operating as a Net Zero educational facility, making it the most energy-efficient school in the State of Kentucky.

To meet the client's project goals, CMTA designed and commissioned Jennings Creek Elementary, and implemented an energy savings performance contract for the state-of-the-art zero energy building.

During the design process, high-efficient heat geo-exchange heat pumps and dedicated outdoor air systems (DOAS) were designed to exceed code requirements for 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. 

A green kitchen, ultra-efficient LED lighting design, and all the strategies listed above, allowed the renewable energy system to be drastically reduced to offset the building's energy consumption. Using a Data-Driven Design, the facilities modeled energy consumption and solar production was compared to the 15-minute interval data for Richardsville Elementary to compare the model to real-world data. The 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 systems were sized at a 330 kW photovoltaic roof-mounted system.

Jennings Creek Elementary was designed to be an energy-efficient building that also prioritizes Occupant Health and Wellness. Zone sensors monitor temperature, humidity, and CO2 levels to adjust the equipment's operating conditions, and bi-polar ionization devices were installed on each item of equipment to improve indoor air quality.

Jennings Creek Elementary 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 coincide 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, will help inform students and integrate curriculum daily. This version of SPHERE is entirely custom for Warren County Public Schools. It not only monitors and shows real-time energy use of Jennings Creek but 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 eco 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 in energy-efficiency and zero energy buildings. 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 facilities' electrical demand charges. Jennings Creek's average monthly peak demand during a 30-minute period of time is 127 kW or 1.5 W/SF, which is ~25% less than similar facilities in Warren County.

Jennings Creek Energy Consumption vs Production

[{"x":"JAN","Consumption":"29961.0","Production":"15634.0"},{"x":"FEB","Consumption":"59780.0","Production":"34956.0"},{"x":"MAR","Consumption":"93945.0","Production":"75425.0"},{"x":"APR","Consumption":"130141.0","Production":"116074.0"},{"x":"MAY","Consumption":"160987.0","Production":"161141.0"},{"x":"JUN","Consumption":"180819.0","Production":"207811.0"},{"x":"JUL","Consumption":"204300.0","Production":"256537.0"},{"x":"AUG","Consumption":"243182.0","Production":"303069.0"},{"x":"SEP","Consumption":"278863.0","Production":"345852.0"},{"x":"OCT","Consumption":"304362.0","Production":"374500.0"},{"x":"NOV","Consumption":"329126.0","Production":"395958.0"},{"x":"DEC","Consumption":"354385.0","Production":"410493.0"}]
What does this data mean?
Consumption: Energy used by the building
Production: Energy generated by the building