california energy commission iepr staff workshop – zne buildings rosenfeld room, energy commission...

California Energy Commission

IEPR Staff Workshop – ZNE Buildings

Rosenfeld Room, Energy Commission Headquarters

May 18, 2015

Farakh NasimBuilding Standards Office

Efficiency Division

[email protected] / 916-654-4689


ZNE Code Building Definition – IEPR 2013

• On-site renewable energy resources =

net annual building energy consumption• Energy = Time Dependent Valuation (TDV)

metric (electricity + natural gas)• Single building seeking building permit with

“entitlements” – opening for community solar to be eligible

• ZNE Code Buildings must meet an Energy Use Intensity Value reflecting best practices for highly efficient buildings


Time Dependent Valuation (TDV)• Time Varying Energy Metric That Accounts for Buildings Using

More Than One Fuel (electricity, natural gas, propane)• Based on the forecasted seasonal and hourly costs for

generating, transmitting, and distributing electricity, and producing and distributing natural gas and propane, for each climate zone

• Recognizes the premium utility costs that must be paid for energy consumed during peak conditions compared to the lower costs during off-peak conditions

• Energy efficiency improvements that drive lower on-peak energy use are highly valued by TDV


ZNE Code Buildings and TDV• ZNE Code building applies to the design and

construction of the building prior to the time the building is reviewed by the building department

• A ZNE Code building does not imply zero utility costs to the homeowner

• Actual utility costs will depend on building operation occurring long after building is permitted and approved for occupancy

• Optimizing solar installations with TDV• PV systems (or other renewables) will be used to offset the

total TDV use caused by the building• Does not ignore natural gas use• Does not require the building to be all electric


Preparing for ZNE in 2016 Standards• 2016 Building Energy Efficiency Standards designed to make

energy efficiency improvements to get loads down as a major step towards Residential ZNE Code Buildings in 2019 Standards

• 2016 Energy Budget Based On:• High Performance Attics and Walls• Tankless Water Heaters• Mandatory requirement for all high efficacy lighting

• Support for builder transition to High Performing Attics and Walls through builder team training programs provided by IOUs


Energy Design Rating


Issues Anticipated by 2013 IEPR• ZNE Code buildings must incorporate on-site renewables to

offset all remaining TDV energy demands of the building• Need to address issues with integrating higher levels of renewable

energy into the distribution grid

• Every building must have a path to compliance• Exception for buildings that cannot accommodate onsite-solar• Need an enforcement framework for off-site renewables

• “Entitlements” for off-site renewables such as systems owned in common or other community solar

• Building department must have reliable, verifiable way to associate off-site renewables with individual home subject to permitting at the time that permit reviews and site inspections occur prior to occupancy


Additional CEC Efforts for 2019 Standards

• Identify additional energy efficiency measures to further reduce loads (including reducing gas use such as solar thermal, other)

• Determine situations where homes can and cannot meet ZNE – develop exceptions to address

• Revise TDV to reflect up-to-date information on utility grid costs• Re-evaluate PV cost effectiveness given CPUC decisions

• NEM policy changes• Utility rate changes

• Revisit plug load assumptions used in performance approach and identify potential ways to reduce plug loads

• Identify ways that PVs can be better integrated with the grid (smart inverters, batteries, other?)


IEPR 2013 Definition Clean-Up

california energy commission iepr staff workshop – zne buildings rosenfeld room, energy commission...

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