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TRANSCRIPT
How Much Energy Do Codes Really Save?
Census Scale Analysis to Measure Energy Code Savings
Nick Taylor
Program for Resource Efficient Communities
University of Florida
March 23rd, 2016
Research Questions
• What are the energy impacts of recent changes to the Austin Energy Code?
• What are the energy impacts of recent changes in Austin Green Building Program?
Community Scale Approach
Source: www.istockphoto.com
Data Sources
• Austin Energy • Daily electric meter readings
• Green Building Program records
• Conservation Program records
• Travis Central Appraisal District • Property Characteristics
• City of Austin • Energy Code Documentation
Data Preparation
Data Preparation
Analytical Methods
• Naïve Regression
• Explains variability
• Does not give exact impact of factors
• Check direction & magnitude of beta coefficients
Energy Consumption
Building type
Beds
Baths
Pool
Other features
Floor Area
Number of Floors
Heating Fuel
(kW
h/y
r)
(kW
h/y
r)
Analytical Methods
• Program Level Savings • Group properties by the building code they were under
• Perform Analysis of Variance (ANOVA) between building code groups • Difference between Average performance of base code group and
Average performance of the code group of interest gives savings
• Statistical significance/validity of the savings is based on the variance in home performance and the confidence interval around each average performance.
• Assume unequal variances in the ANOVA model if the sample sizes are different (as usual)
Analytical Results – Austin Energy Code
Analytical Results - Austin Green Building Program
Best Uses and Lessons Learned
Advantages
• Increases certainty in average savings
• No weather data needed*
• Flexible in timescale and application. • Seasonal savings
• Savings from retrofits
• Assess multiple programs at once
Disadvantages
• Need Large Scale energy dataset
• Database Management
• Cannot assess the impact of individual components of the energy code
Nick Taylor Program for Resource Efficient Communities
University of Florida [email protected] | 352-392-3121