Green Schools: Stewardship of Taxpayer Dollars

FacebookTwitterShare

“Many of the K-12 school districts in the U.S. are broke. The reason there has been such significant uptake in [green schools] all 50 states is about stewardship of taxpayer dollars.”
— Rachel Gutter, Green Schools Program, USGBC

Whether you have kids in school or not, you are aware of the struggle school districts nationwide have maintaining workable operating budgets. Rachel Gutter, head of the Green Schools Program at the U.S. Green Building Council (USGBC), says schools could save 25 percent on their energy costs by employing some basic efficiency measures.

The Alexandria City (Va.) Public Schools (ACPS) system has achieved significant energy savings during the past few years using highly efficient cooling and heating equipment and other efficiency strategies. In 2009, it launched an aggressive environmental protocol called Greenovation, which combines energy-efficient building practices with a unique emphasis on using green building initiatives as a platform for student education.

After ACPS’s renovated T.C. William High School became the first Virginia public school to achieve LEED® Gold status, ACPS wanted to reach even higher sustainability goals. So, when it came time to renovate the 55-year-old T.C. Williams’ Minnie Howard Ninth Grade Campus, ACPS enlisted mechanical engineer Bruce Beddow, founder of b2E Consulting Engineers, P.C., Leesburg, Va.

Called “geo-solar” because it uses the earth (“geo”) and the sun (“solar”) to cool and heat the building, the system at Minnie Howard Ninth Grade Campus involves a creative combination of solar energy (from the sun), geothermal energy (from the earth) and a high-efficiency HVAC (heating, ventilation and air conditioning) system from Mitsubishi Electric Cooling & Heating that simultaneously cools and heats the building. A collection of solar panels provides water heating while serving double duty as a sun shade, reducing glare and saving on cooling costs.

Beddow’s goal was to reduce the building’s energy consumption from a K-12 national average of 74 Btu/h per square foot to 36 Btu/h – a 51 percent annual savings in energy costs. But Beddow achieved much better results — a 63 percent savings, or a total net lifecycle savings of $406,680. The engineer says that this impressive feat was accomplished with a creative combination of solar energy, geothermal and Variable Refrigerant Flow (VRF) ground-source heat pumps from Mitsubishi Electric Cooling & Heating.

The success of the Minnie Howard installation resulted in the ACPS board authorizing a similar geo-solar system for all renovation projects and new schools. After the board’s decision, Beddow brought down the Btu/h per square foot from 36 to 28 at Polk Elementary by adding a photo voltaic array to run the renewable ground-source heat pump system and the solar thermal pumps.

Beddow’s next feat – another huge step in the stewardship of taxpayer dollars — is to bring all ACPS schools down over time to zero Btu/h by installing high-performance building envelopes as well as “plug load” occupancy control. Plug load refers to wares that are plugged into electrical outlets, like task light fixtures, computers, etc. By controlling plug loads during periods of non-use, schools can reap even more energy savings, according to the engineer.