Greenhouse Gas Inventory and Preliminary Energy-Use Analysis of Tucson Unified School District: Fiscal Year 2024

Abstract

This report supports ongoing efforts to reduce climate-related impacts from Tucson Unified School District (TUSD) operations, in alignment with the district’s Climate Action and Sustainability Policy. It establishes a baseline understanding of these impacts through a greenhouse gas inventory covering FY2024, which follows guidance from The Greenhouse Gas Protocol: A Corporate Accounting and Reporting Standard and includes emissions from seven key district activities. The report also provides a detailed assessment of energy use and costs at TUSD facilities through a preliminary building energy-use analysis conducted in accordance with ASHRAE Procedures for Commercial Building Energy Audits. Finally, it identifies several high-level opportunities for emissions reductions. Greenhouse gas emissions from the activities included in this report totaled 63,194 metric tons of CO₂e in FY2024. This amount is approximately equivalent to the carbon sequestered by 63,194 acres of U.S. forests, the emissions from 14,724 gas-powered passenger vehicles, or the energy used by 8,468 homes over the same time period. These emissions are associated with present and future damages with an estimated financial impact of just over $13 million. Of the seven operational activities examined, the purchase of electricity from the grid accounted for nearly two-thirds (60%) of the district’s total greenhouse gas emissions. The second-largest contributor was the disposal of refuse generated at TUSD facilities (17%), followed by on-site combustion of natural gas (11%) and district-owned transportation (8%). Among the four types of schools operated by TUSD, high schools accounted for the largest share of district greenhouse gas emissions. TUSD facilities generally used more energy per square foot than similar institutions in the same climate zone, excluding energy losses that occurred before reaching the building. The district procured electricity from on-site solar installations at 82 facilities through Solar Service Agreements, which reduced the amount of electricity purchased from the grid. Energy use per square foot varied widely across facility types, with several buildings consuming significantly more energy than is typical for TUSD and comparable institutions. Districtwide building energy use in FY2024 was approximately 10% higher than the average observed between FY2021 and FY2023. Key opportunities to reduce emissions include reducing total and peak building energy use; increasing on-site solar generation and energy storage; supporting efforts to decarbonize the electricity grid; prioritizing high-energy-use facilities; consolidating summer operations; implementing waste reduction and diversion programs; and electrifying building equipment and district-owned vehicles. Pursuing these opportunities could also support student apprenticeship programs in partnership with local building trades. To support future reduction efforts, the district should identify an optimal baseline year and clearly define and implement tracking systems for activities included within emissions reduction targets.