Evaluating Energy Efficiency Upgrades to K-12 Public Schools in California Investor-Owned Utility Territories
Catherine Wolfram and Chris Knittel
What kind of energy efficiency investments are most cost-effective for existing buildings? Led by E2e Faculty Directors Catherine Wolfram and Chris Knittel, this project will evaluate energy efficiency upgrades in K-12 schools and allow us to better understand the true costs and benefits of various energy efficiency measures.
Residential and commercial buildings consume massive amounts of energy, accounting for 40% of total U.S. energy consumption in 2013 (EIA). On average, 30% of the energy used in commercial buildings is wasted, resulting in nearly $60 billion in costs and over 5% in carbon dioxide emissions (DOE).
This project focuses on California public K-12 schools within three of the largest electric utilities’ territories. Presently, there is relatively little systematic, publicly available energy use data for these buildings. California has over 10,000 public K-12 schools, over 70% of which are more than 25 years old (the Center for the Next Generation).
Analyzing school site-level energy consumption as a function of demographic characteristics of the schools, weather and other variables should provide insights into how schools use energy and how energy usage varies across schools. By tracking energy use in schools that make a variety of energy efficiency upgrades, we can isolate and identify the impacts of particular investments. For example, if some schools improve their insulation and roofing while others replace their HVAC systems, we can compare electricity usage and cost to determine which was more cost-effective.
The Research Questions
This project will answer several questions:
- What are the true savings of energy efficiency retrofits?
- Which energy efficiency measures are the most effective, in terms of energy savings and cost?
- Which energy efficiency investment combinations create synergies
Summary of the Study
The study is being implemented in collaboration with the California Public Utilities Commission and California utilities. This project will be the first to use electricity interval billing data, which provides data about electricity usage every 15 minutes. This data, combined with natural gas consumption data, will provide a wealth of information that will enable us to evaluate a greater range of energy efficiency measures, but the billing data does not always match the school’s physical location perfectly. Billing data will be matched with the correct schools to create a complete and accurate database of schools and their energy usage.
From this database, we will identify a control group of schools that have not received energy efficiency funding, but that are similar to the schools that did receive funding. By comparing energy usage across schools, we will gain valuable information about the investments that provide the greatest savings and may learn about synergies between different pairings of investments.
Understanding the consequences of energy efficiency programs such as this will allow the CPUC, utilities, and the schools to better understand these programs’ impacts. This knowledge can then inform future decisions not only for schools but also for other large customer bases, while providing some of the first results on commercial building programs.
Graph from the EPA's "Energy Efficiency Programs in K-12 Schools" (link, pdf) and photo from "Financing Energy Upgrades for K-12 School Districts: A Guide to Tapping into Funding for Energy Efficiency and Renewable Energy Improvements" by Merrian Borgeson and Mark Zimring (link, pdf).