Energy Efficiency/Renewable Energy (EERE) Projects in Texas Public Schools Hyojin Kim Zi Liu Juan-Carlos Baltazar Graduate Research Assistant Asst. Research Engineer Assc. Research Engineer Jaya Mukhopadhyay Jeff S. Haberl Sunglok Do Research Associate Professor/Assc. Director Graduate Research Assistant Bahman Yazdani Charles Culp Assc. Director Assc. Professor/Assc. Director Energy Systems Laboratory, Texas A&M University System College Station, TX. ABSTRACT This paper presents the preliminary results from an analysis of the energy saving potential in new and existing Texas Independent School Districts (ISDs). The analysis was performed using a K-12 simulation model based on the DOE-2.1e program that uses ASHRAE Standard 90.1 code-compliant, school buildings for three climate zones in Texas. In this analysis, government and private data sources from the U.S. EPA Energy Star, the Texas Education Agency, and the EnergyPlus Benchmark school models were reviewed to determine the base-case K-12 school characteristics in Texas. Available guidelines and case-studies were reviewed to develop energy efficient measures for high performance school buildings. As a result, four base-case school models that are compliant with the ASHRAE Standard 90.1-1989, 1999, 2004, and 2007 were developed for each climate zone. In addition, a total of eighteen energy efficient measures were considered. These include measures for the building envelope, lighting, HVAC system, DHW system, and renewable energy systems. The proposed energy efficient measures were then applied to the base-case school model to examine the energy saving potential for Texas ISDs. INTRODUCTION Schools are one of the building types with a high energy saving potential from the application of high performance strategies. The most efficient schools use one third the energy than the least efficient schools (EPA 2010). Im and Haberl (2006) reviewed over fifty studies on existing high performance schools. From this review, the annual energy savings from the application of high performance strategies ranged from 20% to 40%. However, to maximize the savings from high performance applications, it is obvious that different strategies are needed for schools built in different years as well as different climate zones. According to the survey of Texas Comptroller of Public Accounts (2006), the average age of Texas elementary, middle, and high schools is 35.2, 32.2, and 32.7 years old, respectively. In addition, the average enrollment of Texas public schools continuously increased over the past 10-year period by 20.1% (TEA 2009). This would indicate that there is a huge energy saving potential in both existing and new schools in Texas from the application of high performance retrofit strategies. This paper presents the preliminary results from an analysis of the energy saving potential in new and existing Texas Independent School Districts (ISDs). The analysis was performed using a K-12 simulation model based on the DOE-2.1e program that uses ASHRAE Standard 90.1 code-compliant, school buildings for three climate zones in Texas according to ASHRAE 90.1-2004 and 2007 climate zone classifications. METHODOLOGY Figure 1 shows the detailed procedure for calculating the potential energy savings for existing K-12 schools in Texas. In this analysis, the existing K-12 schools were classified as three school groups according to the year of construction as Group 1: schools built before 2000; Group 2: schools built between 2000 and 2007; and Group 3: schools built after 2007. To calculate potential energy savings for new high performance K-12 schools in Texas, new schools that will be constructed in 2011 were classified as Group 4, and the total floor area (sq. ft.) of new schools will be estimated using the population growth rate. For the baseline of new schools, ASHRAE Standard 90.1-2007 requirements were referenced. To estimate the savings of all the schools of Texas, simulations for every school in each county should be carried out, which would lead to an extraordinary number of simulations. To simplify the calculation procedure, different counties in Texas were grouped according to ASHRAE 90.1-2004 and ESL-HH-10-08-19Figure 1. Flow Chart for Calculating Potential Energy Savings for Existing K-12 Schools 2007 Climate Zones. Then a representative county in each climate zone was selected such as Harris County for Climate Zone 2, Dallas County for climate zone 3, and Potter County for Climate Zone 4 (Figure 2). For each representative county, four base cases of each school group (based on the year the school was built) that complies with the corresponding requirements of ASHRAE 90.1-1989, 1999, 2004, and 2007 were simulated. Finally, the total energy consumption of the existing and new schools in Texas will be calculated using the simulated energy use intensity (kBtu/sq. ft.) and the surveyed total floor area (sq. ft.) of each school group in each climate zone. Development of Base-Case Model To develop a base-case school model, the following sources were reviewed: the ASHRAE Standard 90.1-1989, 1999, 2004, and 2007, the U.S. EPA Energy Star, the Texas Education Agency (TEA), and the EnergyPlus Benchmark school Figure 2. Climate Zones in ASHRAE Standard 90.1-2004/2007 and Three Selected Counties Grouped Counties by ASHRAE 90.1-2004/2007 Climate ZonesElementary SchoolMiddle SchoolHigh SchoolAvg. No. of Students/This Type of SchoolEnergy Star SchoolTexas Education AgencySchool Model AssumptionsWeather ZoneGroup 1: Base-Case School ModelAssigned Weather StationASHRAE 90.1 1989 Specifications Group 1: Built Before 2000SECO K-12 Energy AuditNo. of This Type of SchoolAvg. Sq. ft. /StudentAvg. Sq. ft./This Type of SchoolYear This Type of School BuiltSchool Compliant with ASHRAE AEDGIndividual Energy Efficiency MeasuresEPlus Benchmark School ModelSurvey of College Station/Bryan ISDsAEDG School Baseline Model Energy Savings for Each Base-case School Energy Savings in This County GroupGroup 2: Built 2000 -2007Group 3: Built 2007-2010ASHRAE 90.1 1999 Specifications ASHRAE 90.1 2004 Specifications School Model AssumptionsSchool Model AssumptionsTotal sq. ft. for Each Base-case School in Each Climate ZoneGroup 2: Base-Case School ModelGroup 3: Base-Case School ModelSimulationCalculationSavings/sq. ft.Estimated No. of This Type of SchoolPopulation Growth RateGroup 4: Built After 2010ASHRAE 90.1 2007 Specifications School Model