Building Energy Benchmarks

1. Building Energy Benchmarks THE WEIDT GROUP

2. Presentation Agenda • Introduction • Comparison of building energy benchmark methods and systems • Comparison of energy use indexes for different benchmark systems for 13 different building types • Recommended Method for Developing Minnesota Benchmarks • How to Disseminate the Sustainable Buildings 2030 Energy Benchmark System

3. Sustainable 2030 Benchmarks 100% 90% 80% 70% 60% 50% Percent CO2 Emissions 40% 30% 20% 10% 0% 2015 2018 2019 2020 2024 2013 2016 2017 2021 2025 2014 2022 2027 2028 2009 2010 2023 2026 2029 2030 2008 2011 2012 Introduction • The Benchmark sets the starting point for CO2 Reduction against which each subsequent target is measure • Targets: Reduce CO2 60% by 2010, 90% by 2030

4. Criteria for a Good Benchmarking system • Easy to use and understand • Accurate – for our climate • Consistent – methodology for all benchmarks • Comprehensive – for all buildings we build and can account for the specific program criteria unique to each building

5. Benchmarking Methods in Use Today • Comparing a building to itself – the “tracking” or “baseline” approach • Empirical model from a sample of other similar buildings in a population– Target Finder / Energy Star approach • Results of an energy simulation model with certain pre-defined baseline characteristics, such as meeting an energy code or standard– current Minnesota B3 Benchmarking and DOE method

6. What are Metrics used to Benchmark Buildings? • For cars we use:Miles per gallon • For lighting efficiency we use:Lumens per Watt • For Cooling equipment efficiency we use:kW/ ton • For buildings we use:Energy Use Intensity (EUI) typically expressed in units of Annual energy consumption per floor area per year kBtu / Square feet / year or maybe …CO2 / Square foot/ year

7. Research Existing Building Energy Benchmarking Systems • Target Finder / Portfolio Manager • 15 different building types – 5 are different hotel types • Minnesota B3 Benchmarking system • Over 50 different building types based of Current MN 1993 Energy Code • New DOE Benchmarking system • Same types as Target Finder based on ASHRAE 90.1 2004 Energy Code

8. Comparison of Benchmark System Features • See Figure 1 System Features on Page 6

9. Comparison of Benchmark System Features • See Figure 1 System Features on Page 6

10. Comparison of energy use indexes for different benchmark systems • Architecture 2030 EPA Target Finder • Architecture 2030 EPA National averages • B3 Models, 1989, Mn 1993, 2004 • DOE 2004 • Sensitivity analysis of operational characteristics to compare how Target Finder and the B3 Benchmarking system account for changes in building operation.

11. All Comparisons

12. System comparisons All CUT

13. Comparisons 1989 B3 to Target Finder Conclusions The ASHRAE 90.1 1989 B3 Benchmark model results and the Target Finder results are the best fit of data systems compared in this study.

14. Comparison of 1989 B3 to Architecture 2030 National Averages Conclusions The national average data is national average data; it occasionally resembles Minnesota data but usually does not. It is not a valid method for setting benchmarks for Minnesota buildings.

15. Sensitivity Analysis for Operational Characteristics Conclusions: Changes in operating hours and the conditioned area of the building, have significant impacts on establishing the buildings benchmark. Variations in the parameters studied show impacts up to 25%. We will need a system that accounts for these variations to develop an accurate Benchmark System.

16. Recommended Method for Developing Minnesota Benchmarks • The 2004 code is too stringent, would be difficult to achieve 60%. • Target Finder can not be extended to a larger range of building types – we want a consistent methodology used for all building types. • The National Average EUI’s developed by the Architecture 2030 team are not accurate for running a program in this State.

17. Recommendation: Use the ASHRAE 1989 90.1 Energy Code • A very efficient analysis method for creating a comprehensive list of building types • It will not require expensive data collection of existing building energy use • The code is a rule based system that can be modeled consistently and accurately for all building types. • The ASHRAE 90.1 1989 model data is closest to Target Finder results. • The ASHRAE 90.1 1989 has been the code in place until recently and closely follows the intent of the Architecture 2030 program • Subsequent Code improvements can be easily benchmarked to identify how they alone improve the EUI from the 1989 baseline.

18. Establish Savings Targets from the Benchmark • Architecture 2030 proposes the same % reduction for all building types. • For 2010 it establishes a 60% reduction in consumption • Is this feasible for all building types?

19. Establish Savings Targets from the Benchmark The equivalent percentage savings ranges from 62% for the Small Hotel to 40% savings for the Warehouse building type. This analysis raises the question of using a standard savings percentage for all building types or having it vary based on building type.

20. Analysis of Hospital savings opportunities 32 % Savings Conclusion: Hospitals are one example where current technologies and design methods are not available to reduce energy consumption by 60% today.

21. Development of Building Energy Benchmarks for “Typical” Building Types • We are completing work on simulating Energy Benchmarks for over 30 different building types. • We have researched average building characteristics from the DOE models and hundreds of projects we have archived. • These models utilize average building characteristics by building type for: • Space use type • Space use distribution • Operational schedules for lights, plugs, etc. • Envelope parameters • HVAC parameters

22. Development of Building Energy Benchmarks for “Typical” Building Types • What we have found from our review of the data is there is a large variation in consumption results for “Typical” Building types. • The large variation in consumption results is due to the large variation in each projects unique building program requirements, mainly: • Space use type • Space use distribution – this can be significant • Operational schedules for lights, plugs, etc. • HVAC parameters

23. Sample Distribution of Code Base Office Building Consumption Average kBtu/ SF/ YR

24. Office Building Percentage Difference from Average

25. Dissemination of the Sustainable Buildings 2030 Energy Benchmark System • A web-based calculation tool will be developed to allow project designers to: • Use “default” building characteristic or have the ability to “customize” characteristics based on their unique building program elements. • Editable building characteristics will include: • Building location • Building gross floor area • Building type(s) • Number of floors • Space type, floor area% and hours of use. • Cooling and heating system • Fuel source types for building

26. Dissemination of the Sustainable Buildings 2030 Energy Benchmark System • After results are entered the web-based tool will calculate: • Total Energy Target Standard in kBtu/SF goal based on 2030 savings criteria. • Fuel source end use in kBtu/SF for the Target Standard. • Target Standard CO2 emissions by fuel source.

27. Summary • We can’t use National Averages • We can’t use Target Finder • We need a lot of space type and operational variables • Modeled data can provide us the flexibility and accuracy we need • Modeled data aligns well with the intent of 2030 • ASHRAE 89 is the best code base to use to reflect the intent of 2030 • We need to formulate the appropriate range of % savings by building type to be cost-effective.

28. THE WEIDT GROUP