Parkway School District: South High School

BACKGROUND

Parkway South High School is the largest school and most significant energy consumer in Parkway School District. The school became a prime candidate for a long-term, sustainable solution in 2016 after one of two chillers in its aging chiller plant became non-functional. As part of an energy savings performance contract, a central geothermal plant was installed in addition to building envelope sealing and LED lighting. Installation of a 75 kW solar array and retro-commissioning were also recently completed onsite.

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SOLUTIONS

Replacing fluorescent lights with more energy efficient LED lighting and occupancy sensors was a relatively simple way to decrease the school's energy use. Building envelope improvements included upgrading the insulation and installing new roofing. Geothermal energy is renewable and does not produce greenhouse gasses, so installing a new geothermal plant for the school lessened its environmental impact and helped to decrease overall energy use and expense.

 

Savings Measure

Cost

Savings Achieved

Notes

Geothermal/Chiller Plant Upgrades

$2,713,279

1,372,935 kWh

New heater-chiller plant to replace aging chillers and eliminate existing heating boilers. Borefield with 120 vertical wells 500 ft deep.

Building Envelope Upgrades

$70,585

160,466 kWh

 

LED lighting retrofits and controls

$191,136

420,177 kWh

 

75 kW solar PV array

$149,975

99,167 kWh

In addition to previously installed 25 kW array bringing total onsite capacity to 100 kW of rooftop solar PV.

 

Retro-commissioning work helped to identify where improvements and changes needed to be made to help the school's HVAC system conserve energy. Some of the changes involved making sure that equipment was running only when needed, and that sensors were properly calibrated.

Savings Measure

Cost

Savings Achieved

Notes

RCx - DAT/DSP Reset

$4,365

101,000 kWh

Create reset schedules for various AHUs, based upon Terminal Unit demand.

RCx – CO2 Control & TAB

$157,325

469,000 kWh

Utilize Existing CO2 Sensors to reduce minimum airflow requirements in spaces when unoccupied. Calibrate airflow sensors supplying excessive. Allow cooling minimum airflow setpoint to fall to 0 during unoccupied times.

RCx – RTE-014 On/Off

$2,800

171,000 kWh

Two units were running constantly due to existing setpoints –ON/OFF settings altered to ensure the units turn off during unoccupied.

RCx – Unoccupancy Setpoints and Temp Range Modifications

$5,265

16,400 kWh

Update setpoint that calls for the units to start during unoccupied times. Adjust the user controls of common spaces locking out adjustment controls to BAS only. Correct simultaneous heating and cooling in one of the air handlers.

 
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OTHER BENEFITS

Parkway secured utility rebate incentives totaling $228,963 across all of the projects. South High’s ENERGY STAR score has increased by 65% going from 43 to 71. These measures are expected to improve the overall performance of the building and reduce maintenance needs and costs. The geothermal plant is designed for a longer lifespan while providing opportunities to continue tying in sections of the building over time.

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Annual Energy Use

(Source EUI)
Baseline (2017)
163 kBtu/sq.ft.
Actual (2021)
129 kBtu/sq.ft.

Energy Savings:

21%

Annual Energy Cost

Baseline (2017)
$468,404
Actual (2021)
$363,848

Cost Savings:

$104,556

Sector Type

Education

Location

Manchester, Missouri

Project Size

336,274 square feet

100 kW rooftop solar arrays
100 kW of rooftop solar arrays provide clean energy to the building and help to reduce energy bills.

Drilling of geothermal system
120 vertical wells are drilled 500 ft deep into a field adjacent to the building.

Student engagement of onsite geothermal system
Students from Parkway South High School learn about geothermal energy at the test well built near the school in 2018.