(1)Existing law requires the State Energy Resources Conservation and Development Commission to prescribe, by regulation, lighting, insulation climate control system, and other building design and construction standards that increase the efficiency in the use of energy and water for new residential and new nonresidential buildings. Existing law also requires the commission to prescribe, by regulation, energy and water conservation design standards for new residential and new nonresidential buildings. In order to implement these requirements, existing law requires the commission to develop a public domain computer program that enables contractors, builders, architects, engineers, and government officials to estimate energy consumed by residential and nonresidential buildings.

This bill would require the commission to approve and make publicly available, not less than 6 months prior to the effective date of adopted or updated efficiency standards, a version of the public domain computer program that will function properly with these adopted or updated standards. The bill would require the commission, before approving the public domain computer program for use with adopted or updated standards, to perform preliminary tests of the public domain computer program using common examples of residential and nonresidential buildings and building systems to ensure the usability of the program. The bill would require the commission to make the results of those preliminary tests publicly available.

(2)Existing law requires the commission to establish criteria for adopting a statewide home energy rating program for residential dwellings.

For existing single-family residential dwellings and multifamily residential dwellings with up to 4 units, this bill would require the commission, in administering the statewide home energy rating program, to ensure that energy assessment tools used approved by the commission are routinely adjusted to improve modeling accuracy and to ensure that consumers receive a notice with the output of the energy assessment tools explaining the assumptions used in the energy assessment tools and how they may differ from actual usage patterns.

(1)Existing law requires the State Energy Resources Conservation and Development Commission to prescribe, by regulation, lighting, insulation climate control system, and other building design and construction standards that increase the efficiency in the use of energy and water for new residential and new nonresidential buildings. Existing law also requires the commission to prescribe, by regulation, energy and water conservation design standards for new residential and new nonresidential buildings. In order to implement these requirements, existing law requires the commission to develop a public domain computer program that enables contractors, builders, architects, engineers, and government officials to estimate energy consumed by residential and nonresidential buildings.

This bill would require the commission to approve and make publicly available, not less than 6 months prior to the effective date of adopted or updated efficiency standards, a version of the public domain computer program that will function properly with these adopted or updated standards. The bill would require the commission, before approving the public domain computer program for use with adopted or updated standards, to perform preliminary tests of the public domain computer program using common examples of residential and nonresidential buildings and building systems to ensure the usability of the program. The bill would require the commission to make the results of those preliminary tests publicly available.

(2)Existing law requires the commission to establish criteria for adopting a statewide home energy rating program for residential dwellings.

For existing single-family residential dwellings and multifamily residential dwellings with up to 4 units, this bill would require the commission, in administering the statewide home energy rating program, to ensure that energy assessment tools used by the commission are routinely adjusted to improve modeling accuracy and to ensure that consumers receive a notice with the output of the energy assessment tools explaining the assumptions used in the energy assessment tools and how they may differ from actual usage patterns.

SENATE COMMITTEE ON APPROPRIATIONS

Senator Ricardo Lara, Chair

2015 - 2016 Regular Session

AB 1013 (Quirk) - Energy: public domain computer program: home energy rating.

This bill meets the criteria for referral to the Suspense File.

Bill Summary:

AB 1013 would require the California Energy Commission (CEC) to approve and make publicly available a public domain computer program that reflects adopted or updated building standards and has been tested and updated to improve accuracy for use on single-family and multifamiliy residential dwellings.

Fiscal Impact:

• Ongoing costs of approximately $1 million for staff and contracts from the Energy Resources Programs Account (General) to continuously improve modeling accuracy of the energy assessment tools for residential dwellings.

Background:

Section 25402.1 of the Public Resources Code requires the CEC to develop a public domain computer program that will enable contractors, builders, architects, engineering, and government officials to estimate the energy consumed by residential and nonresidential buildings. This program, known as the Public Domain Compliance Software, is used to demonstrate compliance with building energy efficiency standards.

Section 25942 of the Public Resources Code requires the CEC to adopt criteria for adopting a statewide home energy rating program for residential dwellings. Home energy rating services must in compliance with the program criteria. In response to this requirement, the CEC developed the Home Energy Rating System (HERS) program. HERS providers use software (often Energy Pro, which is CEC approved) to estimate the energy savings that will occur in any given building as a result of efficiency upgrades.

Proposed Law:

This bill would:

• Require the CEC to approve and make publicly available, not less than six months prior to the effective date of adopted or updated standards, a version of the public domain computer program that will function properly with those adopted or updated standards.

• Require the CEC, before approving the public domain computer program for use with adopted or updated standards, to (1) perform preliminary tests of the public domain computer program using common examples of residential and nonresidential buildings and building systems to ensure the usability; and to (2) make the results of the preliminary tests publicly available.

• Require the CEC, as part of the home energy rating program, for existing single-family residential dwellings and multifamily residential dwellings with up to four units, to (1) ensure energy assessment tools used by the commission are routinely adjusted to improve modeling accuracy; and to (2) ensure that consumers receive a notice with the output of the energy assessment tools explaining the assumptions used in the energy assessment tools and how the output may differ from actual usage patterns.

Related Legislation:

AB 2581 (Bradford, 2014) would have made changes to CEC building energy efficiency standards programs virtually identical to this bill, as well as changes to CEC’s appliance energy efficiency standards. The bill was vetoed by the Governor.

Staff Comments:

In regards to the Public Domain Computer Program, the changes proposed by the bill are consistent with CEC’s current practice and therefore will not result in additional costs.

In regards to the HERS program, this bill would require that energy assessment tools used by the CEC are routinely adjusted to improve the tools accuracy in estimating anticipated energy savings. To make such adjustments, the CEC will need to regularly obtain energy usage data from single-family and multi-family buildings that have received an assessment using the CEC tools in order to compare estimated energy usage with actual usage. Any differences would result in modifying the assessment tools. The CEC anticipates needing approximately $500,000 in contract costs for data collection and analysis assistance plus approximately $500,000 in additional staff to continuously improve modeling accuracy.

As noted by the Senate Committee on Energy, Utilities, and Communication, “The author and industry representatives contend that the accuracy and usefulness of software used by HERS Raters would be improved by routine adjustments. They further contend that home owners would be better served if CEC ensured home owners were informed of the assumptions behind CEC-approved energy assessment tools and how actual energy usage may vary from assessment tool estimates. There is no reason to contradict the proponents – the practices required by the bill likely would improve the accuracy and usefulness of CEC-approved software in estimating homeowner energy savings. However, CEC reports that the modeling adjustments will be complex and costly. It is not clear the improvements that would result from routine adjustments to CEC-approved software would merit the cost of such adjustments.”

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SENATE COMMITTEE ON ENERGY, UTILITIES AND COMMUNICATIONS

Senator Ben Hueso, Chair

2015 - 2016 Regular

Bill No: AB 1013 Hearing Date: 6/16/2015

SUBJECT: Energy: public domain computer program: home energy rating

DIGEST: This bill makes various changes to the California Energy Commission’s (CEC) implementation of its building energy efficiency standards and its related home energy rating system (HERS) program.

ANALYSIS:

Existing law:

1. Requires CEC to issue cost-effective regulations regarding building design construction for new building and for appliances to reduce the wasteful, uneconomic, inefficient, or unnecessary consumption of energy, including the energy associated with the use of water. (Public Resources Code §25402 et seq)

2. Requires CEC to develop a public domain computer program that enables contractors, builders, architects, engineers, and government officials to estimate the energy consumed by residential and nonresidential buildings. (Public Resources Code §25402.1(a))

3. Requires CEC to adopt a statewide HERS program for residential dwellings that allows consistent, accurate, and uniform ratings of the energy efficiency of California homes and prioritization of potential investments in energy efficiency measures. (Public Resources Code §25942)

This bill:

1. Requires CEC to approve and make publicly available, not less than six months prior to the effective date of adopted or updated standards, a version of the public domain computer program that will function properly with those adopted or updated standards. 

2. Requires CEC, before approving the public domain computer program for use with adopted or updated standards, to (a) perform preliminary tests of the public domain computer program using common examples of residential and nonresidential buildings and building systems to ensure the usability; and to (b) make the results of the preliminary tests publicly available.

3. Requires the CEC, as part of the home energy rating program, for existing single-family residential dwellings and multifamily residential dwellings with up to four units, to (a) ensure energy assessment tools used by the commission are routinely adjusted to improve modeling accuracy; and to (b) ensure that consumers receive a notice with the output of the energy assessment tools explaining the assumptions used in the energy assessment tools and how the output may differ from actual usage patterns.

Background

Public domain compliance software. The Warren-Alquist Act requires CEC to, among other things, establish a process for certifying calculation methods to demonstrate compliance with its building energy efficiency standards.  The process CEC established is its Public Domain Compliance Software. Building industry professionals use the software to demonstrate building energy use for compliance with CEC’s building energy efficiency standards.  The software rates the energy efficiency of a newly constructed building as an asset – a single-family home, an office building, etc. – and compares it to other similar, newly constructed assets.  Industry professionals can use the software to evaluate the effects of different building features on a building, operated under assumed conditions, against other buildings with different features, operated under the same assumed conditions.

Industry professionals report problems with CEC’s past roll outs of the software updates that reflect new or updated building energy efficiency standards. The author and industry representatives contend that such problems could likely be avoided if they had access to a version of the software before the new or updated standards took effect and if CEC made public the testing of such software. For this reason, the bill requires CEC to make such software available at least six months prior to the effective date of the new or updated standards and requires CEC to test it using certain parameters, the results of which CEC is to make public. The CEC reports that both of these requirements accord with CEC’s current practice.

Home energy rating system and the use of software. Public Resources Code §25942 directs CEC to conduct a statewide home energy rating program for residential dwellings. The program’s goal, according to CEC, is “reasonable estimates of potential utility bill savings, and reliable recommendations on cost-effective measures to improve energy efficiency.” 

In response, CEC established the HERS program. The program operates as follows:

• The CEC approves “HERS Providers” to train and certify “HERS Raters.”

• HERS Raters conduct HERS verification in (i) residential and nonresidential newly constructed buildings, additions and perform California Whole-House Home Energy Ratings – a comprehensive evaluation of the energy efficiency of the entire home.

HERS Raters often times use CEC-approved software to help homeowners estimate the energy usage they might realize after making an energy efficiency upgrade. Industry representatives report that some of these software-based energy assessment tools have provided inaccurate estimates of energy savings, despite having been approved by CEC for such use.

The author and industry representatives contend that the accuracy and usefulness of software used by HERS Raters would be improved by routine adjustments. They further contend that home owners would be better served if CEC ensured home owners were informed of the assumptions behind CEC-approved energy assessment tools and how actual energy usage may vary from assessment tool estimates. There is no reason to contradict the proponents – the practices required by the bill likely would improve the accuracy and usefulness of CEC-approved software in estimating homeowner energy savings. However, CEC reports that the modeling adjustments will be complex and costly. It is not clear the improvements that would result from routine adjustments to CEC-approved software would merit the cost of such adjustments.

Who’s using whom? The bill requires CEC to ensure energy assessment tools are routinely adjusted. In doing so, the bill references “energy assessment tools used by the commission.” This statement inaccurately reflects CEC’s relationship with the energy assessment tools. This is because CEC does not “use” such tools; rather, it approves them. The author and committee may wish to amend the bill as follows:

(f) For existing single-family residential dwellings and multifamily residential dwellings with up to four units, the commission shall do both of the following in administering the statewide home energy rating program:

(1) Ensure energy assessment tools used approved by the commission are routinely adjusted to improve modeling accuracy.

(2) Ensure that consumers receive a notice with the output of the energy assessment tools explaining the assumptions used in the energy assessment tools and how they may differ from actual usage patterns.

Prior/Related Legislation

AB 2581 (Bradford, 2014) would have made changes to CEC building energy efficiency standards programs identical to this bill, as well as changes to CEC’s appliance energy efficiency standards. The bill was vetoed by the Governor, who opined the bill described CEC’s existing practices and did not provide CEC with new authority.

FISCAL EFFECT: Appropriation: No Fiscal Com.: Yes Local: No

ASSEMBLY VOTES:

Assembly Floor (79-0)

Assembly Appropriations Committee (17-0)

Assembly Utilities and Commerce Committee (14-0)

SUPPORT:

California Building Industry Association

California Business Properties Association

OPPOSITION:

None received

ARGUMENTS IN SUPPORT: Proponents contend that, while CEC has taken steps to ensure its next roll out of energy-code standards will be better than past roll outs, this bill establishes minimum levels of action that would be nonetheless well-received by energy-code users.

-- END --

ASSEMBLY THIRD READING

ATR Bill Id:AB 1013

Author:(Quirk)

As Introduced Ver:February 26, 2015

Majority vote

SUMMARY: Makes various changes in statutes related to the California Energy Commission’s (CEC) building standards. Specifically, this bill:

1. Makes various changes to building standard statutes, including provisions that:

   1. Requires the CEC, before approving the public domain computer program that estimates energy consumption, to perform preliminary tests of the software using examples of common residential and non-residential building, and to make the results of the tests publicly available.

   2. Requires the CEC to ensure its computer program that estimates energy consumption is available at least six months before the effective date of adopted or updated standards.

   3. Requires the CEC to routinely adjust the software to improve modeling accuracy for use within single-family residential dwellings and multi-family residential dwellings with up to four units.

   4. Requires end-users of the public domain computer program to provide consumers, along with the output of the energy assessment tool, with a notice explaining how assumptions used by the computer program may be different than actual energy use.

FISCAL EFFECT: According to the Assembly Appropriations Committee, Increased annual costs of $972, 000 ($472,000 for CEC to hire staff and $500,000 for increased annual contracts) (Energy Resources Program Account) to obtain data, develop and maintain database systems, and identify the differences between actual energy usage and tool estimates.

COMMENTS:

1. Author’s Statement: "Energy efficiency is the top priority in California's policies to achieve energy savings and reduce greenhouse gas emissions. There are numerous programs … that offer consumers incentives or rebates to purchase energy efficiency appliances and construct or install energy efficient devices or technologies in residential and commercial buildings. Before participating in these programs, customers may undergo an energy assessment to examine energy saving opportunities in their particular building. However, the software tools approved by the CEC that are used to estimate energy usage are not sufficiently accurate and consistently overestimate energy usage. Generally, it has been observed that software-based energy analysis of inefficient existing homes tends to over predict pre-retrofit energy use and retrofit energy savings. It is important that these simulation results be calibrated to actual energy usage to help customers understand how their investment will likely affect their energy use if their occupant behavior remains the same after energy efficiency improvements are installed."

2. Background: The CEC is required to carry out studies, technical assessments, research projects, and data collection directed in order to adopt energy and water efficiency standards for appliances and buildings to reduce wasteful, inefficient, unnecessary, or uneconomic uses of energy. Numerous programs offer consumers incentives or rebates to purchase energy efficient appliances and construct or install devices in residential and commercial buildings. Before participating in these programs, customers may undergo an energy assessment to identify energy savings in their buildings. The CEC is also required to develop a public domain computer program to estimate energy consumed by residential and nonresidential buildings.

3. Energy Assessments and Ratings: An energy assessment examines opportunities in a particular building in order to find potential energy saving upgrades. Based on standard assumptions of occupant behavior, ratings are used to compare the energy efficiency of one building to others. A variety of software tools are available to perform assessments and ratings, and some contractors have even created proprietary in-house tools. These methods involve inputting information about a building into a building energy simulation program and running the program to predict energy use. Some studies have raised concerns about the accuracy of energy analysis software. These studies found that software-based energy analysis of inefficient existing homes tends to over predict pre-retrofit energy use and retrofit energy savings.

This bill would require the CEC to perform preliminary tests of the software using examples of common residential and non-residential buildings before approving the public domain computer program, and make those results publically available. This bill would also require the CEC to make the program available six months before the effective date of adopted or updated building standards. Furthermore, this bill would require the CEC to routinely adjust the software to improve modeling accuracy, and notify consumers about how assumptions used by the program may be different than actual energy use. All this serves to ensure that the CECs public domains computer program is accurate before it is released, and updated routinely to ensure that consumers are provided the most accurate data possible.

Analysis Prepared by: Edmond Cheung / U. & C. / (916) 319-2083 FN: 0000616

Date of Hearing: April 29, 2015

ASSEMBLY COMMITTEE ON APPROPRIATIONS

Jimmy Gomez, Chair

ABPCA Bill Id:AB 1013

Author:(Quirk) – As Introduced Ver:February 26, 2015

Urgency: No State Mandated Local Program: No Reimbursable: No

SUMMARY:

This bill expands the California Energy Commission's (CEC) building standards provisions relating to public domain computer systems. Specifically, this bill:

1. Requires CEC, before approving the public domain computer program that estimates energy consumption, to perform preliminary tests of the software and to make the results of the tests publicly available.

2. Requires CEC to ensure its computer program that estimates energy consumption is available at least six months before the effective date of adopted or updated building standards.

3. Requires CEC to routinely adjust the software to improve modeling accuracy for single-family residential dwellings and multi-family residential dwellings with up to four units.

4. Requires end-users of the public domain computer program to provide consumers, along with the output of the energy assessment tool, with a notice explaining how assumptions used by the computer program may be different than actual energy use.

FISCAL EFFECT:

Increased total annual costs of $972,000 to obtain data, develop and maintain database systems, and identify the differences between actual energy usage and tool estimates (Energy Resources Program Account). This figure includes $472,000 for CEC to hire staff and $500,000 for increased annual contracts.

COMMENTS:

1. Rationale. CEC is required to continuously carry out studies, technical assessments, research projects, and data collection directed to reduce wasteful, inefficient, unnecessary, or uneconomic uses of energy. As part of this requirement, CEC adopts energy and water efficiency standards for appliances and buildings. CEC is also required to develop a public domain computers program to estimate energy consumed by residential and nonresidential buildings.

Numerous programs offer consumers incentives or rebates to purchase energy efficient appliances and construct or install devices in residential and commercial buildings. Before participating in these programs, customers may undergo an energy assessment to identify energy savings in their buildings

However, according to the author, the software tools approved by CEC used to estimate energy usage are not sufficiently accurate and consistently overestimate energy usage.

This bill will improve the accuracy and availability of public domain software programs to assist consumers in identifying potential energy savings in residential and nonresidential buildings.

2. Energy Assessments and Ratings. An energy assessment examines opportunities in a particular building in order to find potential energy saving upgrades. Based on standard assumptions of occupant behavior, ratings are used to compare the energy efficiency of one building to others. A variety of software tools are available to perform assessments and ratings, and some contractors have even created proprietary in-house tools. These methods involve inputting information about a building into a building energy simulation program and running the program to predict energy use. Studies have raised concerns about the accuracy of energy analysis software. These studies found that software-based energy analysis of inefficient existing homes tends to over predict pre-retrofit energy use and retrofit energy savings.

Analysis Prepared by: Jennifer Galehouse / APPR. / (916) 319-2081

Date of Hearing: April 20, 2015

ASSEMBLY COMMITTEE ON UTILITIES AND COMMERCE

Anthony Rendon, Chair

ABPCA Bill Id:AB 1013

Author:(Quirk) – As Introduced Ver:February 26, 2015

SUBJECT: Energy: public domain computer program: home energy rating

SUMMARY: This bill would make various changes in statutes related to the California Energy Commission’s (CEC) building standards. Specifically, this bill:

1. Makes various changes to building standard statutes, including provisions that:

1. Requires the CEC, before approving the public domain computer program that estimates energy consumption, to perform preliminary tests of the software using examples of common residential and non-residential building, and to make the results of the tests publicly available.

2. Requires the CEC to ensure its computer program that estimates energy consumption is available at least six months before the effective date of adopted or updated standards.

3. Requires the CEC to routinely adjust the software to improve modeling accuracy for use within single-family residential dwellings and multi-family residential dwellings with up to four units.

4. Requires end-users of the public domain computer program to provide consumers, along with the output of the energy assessment tool, with a notice explaining how assumptions used by the computer program may be different than actual energy use.

EXISTING LAW:

1. Requires the CEC to continuously carry out studies, technical assessments, research projects, and data collection directed to reducing wasteful, inefficient, unnecessary, or uneconomic uses of energy, including improved appliance efficiency. (Public Resources Code §25401)

2. Requires the CEC to adopt cost-effective energy and water efficiency standards for appliances. (Public Resources Code §25402)

3. Requires the CEC to develop a public domain computer program to estimate energy consumed by residential and nonresidential buildings. (Public Resources Code §25402.1 (a)(1))

4. Requires the CEC to certify compliance options for new products, materials, and calculation methods in order to meet the energy efficiency standards. (Public Resources Code §25402.1 (a)(2))

FISCAL EFFECT: Unknown.

COMMENTS:

1. Author’s Statement: “Energy efficiency is the top priority in California’s policies to achieve energy savings and reduce greenhouse gas emissions. There are numerous programs … that offer consumers incentives or rebates to purchase energy efficiency appliances and construct or install energy efficient devices or technologies in residential and commercial buildings. Before participating in these programs, customers may undergo an energy assessment to examine energy saving opportunities in their particular building. However, the software tools approved by the CEC that are used to estimate energy usage are not sufficiently accurate and consistently overestimate energy usage. Generally, it has been observed that software-based energy analyze of inefficient existing homes tends to over predict pre-retrofit energy use and retrofit energy savings. It is important that these simulation results be calibrated to actual energy usage to help customers understand how their investment will likely affect their energy use if their occupant behavior remains the same after energy efficiency improvements are installed.”

2. Background: The California Global Warming Solutions Act of 2006, enacted by AB 32 (Nunez) Chapter 488, Statutes of 2006, tasked the Air Resources Board to adopt rules and regulations that would reduce greenhouse gas emissions in the state to 1990 levels by 2020. With it, the Legislature acknowledged the adverse impacts and threat global warming poses to the economic wellbeing, public health, natural resources, and environment of California, and took an active step towards mitigating its effect.

Achieving the goals set out by AB 32 includes finding ways to promote greater energy efficiency in existing buildings.  In order to reduce energy consumption in buildings, California developed Title 24 building standards that address the energy efficiency of new homes and commercial buildings. As new buildings are built, they are built to standards that reduce the growth of electricity and gas use by its occupants. However, there still remain over 8 million homes, accounting for approximately 75 percent of California’s homes and apartments that were built prior to the establishment of the Title 24 building standards. Many of these older homes have not been upgraded to use less energy, and finding ways to retrofit these pre-Title 24 buildings to improve their efficiency serves as a method to achieving continuing greenhouse gas emission reductions for the state.

Subsequently, the legislature passed AB 758 (Skinner) Chapter 470, Statutes of 2009, required the CEC, in collaboration with the California Public Utilities Commission (CPUC) and stakeholders, to develop a comprehensive program to achieve greater energy savings in the state’s existing residential and nonresidential building stock. The bill sought to develop a plan for the state and homeowners to retrofit existing buildings in order to lower utility cost, energy consumption, and greenhouse gas emissions.   

3. Energy Upgrade California: Energy Upgrade California is a statewide initiative designed to help California meet the climate action and energy efficiency goals of AB 32 and AB 758. Energy Upgrade California is an alliance of the CPUC, CEC, utilities, regional energy networks, local governments, businesses, and nonprofits to offer financial incentives to homeowners who complete certain energy-saving home improvements. The program seeks to guide Californians to conserve energy, reduce demand on the electrical grid, and make informed energy management choices.

The financial incentives are designed to reward homeowners who address energy efficiency needs through a comprehensive “whole house” approach. Depending on their improvement needs and budget, homeowners can choose between various incentives – typically upgrades such as air sealing, attic insulation, and duct sealing must be combined with upgrades to wall, floor, and duct insulation and/or heating and cooling equipment.

4. Energy Assessments and Ratings: An energy assessment examines opportunities in a particular building in order to find potential energy saving upgrades. Based on standard assumptions of occupant behavior, ratings are used to compare the energy efficiency of one building to others. A variety of software tools are available to perform assessments and ratings, and some contractors have even created proprietary in-house tools. These methods involve inputting information about a building into a building energy simulation program and running the program to predict energy use. Examples of modeling software that estimate energy usage include EnergyPro, Home Energy Saver, and HEED.

Some studies have raised concerns about the accuracy of energy analysis software. These studies found that software-based energy analysis of inefficient existing homes tends to over predict pre-retrofit energy use and retrofit energy savings. For example, a report prepared for PG&E and Southern California Edison found that modeling software consistently overestimated the energy use of each home. Modeled pre-retrofit annual energy use was compared with actual billing data for 30 jobs, showing:

1. mean modeled total annual use was 40% greater than billed use,

2. mean modeled annual kWh use was 56 to 68% greater than billed use, and

3. mean modeled annual gas use was 39 to 43% greater than billed use.

The study found that estimates prepared by the EnergyPro and eQUEST software were significantly different from each other and overestimated energy use.

Another study by the Earth Advantage Institute and the Conservation Services Group compared software-based energy use projections for 192 existing homes to actual energy bills and calculated the percent errors. SIMPLE had a mean absolute percent error of 25.1%, compared to HES-Full with 33.4%, REM/Rate with 43.7%, and HES-Mid with 96.6%. In other words, SIMPLE predicted energy use on average within plus or minus 25.1% of actual use.

This bill would require the CEC to perform preliminary tests of the software using examples of common residential and non-residential buildings before approving the public domain computer program, and make those results publically available. The bill would also require the CEC to make the program available six months before the effective date of adopted or updated building standards. Furthermore, this bill would require the CEC to routinely adjust the software to improve modeling accuracy and notify consumers about how assumptions used by the program may be different than actual energy use. All this serves to ensure that the CECs public domains computer program is accurate before it is released, and updated routinely to ensure that consumers are provided the most accurate data possible.

5. Prior Legislation:

AB 2581 (Bradford) 2014: Makes various changes in statutes related to the California Energy Commission’s adoption and use of appliance and building standards. Vetoed by the Governor.

REGISTERED SUPPORT / OPPOSITION:

Support

None on file.

Opposition

None on file.

Analysis Prepared by: Edmond Cheung / U. & C. / (916) 319-2083