855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 340
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Consistent with ASHRAE 90.1 G2.4, this path credits the on-site renewable contribution for the project. Prior to calculating the proposed building performance (PBP), subtract eligible on-site renewable energy generation from the proposed design energy consumption. Total savings documented for on-site renewable electricity generation can be up to 100% of building electricity use on an annual basis. To qualify for credit compliance, the on-site renewable energy must be installed and commissioned within the project scope of work or an earlier scope of work on the site of a contiguous campus with all renewable attributes allocated to the project.
Plug and process efficiency For EAc3: Enhanced Energy Efficiency, projects may document credit for plug and process efficiency using ASHRAE 90.1, G2.5 Exceptional Calculation Method.
Document that each process efficiency measure is not conventional practice. Provide detailed calculations and narrative justification supporting the future source energy savings claimed. (See additional guidance above from Option 1, Path 2, Case 3 Plug and Process Load Exceptional Calculation). To convey the magnitude of impact associated with process efficiency measures, the energy analyst must separately report the Performance Index, Performance Index Target, and all associated terms with- and without- the process efficiency savings.
District energy For EAc3: Enhanced Energy Efficiency, energy analysts may optionally replace prescriptive purchased heat and purchased chilled water efficiencies modeled per ASHRAE 90.1-2022, Addendum a with improved virtual DES efficiencies representative of the DES purchase heat and purchased chilled water systems serving the project.
Provide an engineering analysis based on monitored data and/or energy simulation to justify the improved virtual DES efficiencies modeled for the project. For each DES source, virtual DES efficiency must account for total annual energy required to generate and distribute the district energy. Include all pump energy use from the DES and within the project, thermal distribution losses, heat rejection, and all operational effects influencing efficiency such as standby losses, equipment cycling, equipment staging, and partial-load operation. When thermal distribution losses are not measured or modeled, estimate default losses of 5% for chilled water, 10% for hot water, 15% for closed-loop steam, and 25% for open-loop steam.
No further adjustments are required to a Baseline Building Performance model with purchased heat and purchased chilled water documented per ASHRAE 90.1-2022, Addendum a in EAp2: Minimum Energy Efficiency.
U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 330