New District Energy Guidance for LEED Released by USGBC
Updated DES guidance is here!
For months I've been replying to campus and multi-building posts on the LEEDuser forum with statements like, "The official USGBC guidance on district energy systems in LEED is very helpful in your situation, although that guidance hasn't yet been updated for 2009 projects." I'm very glad that as of today that statement will no longer be necessary! USGBC has released Treatment of District or Campus Thermal Energy in LEED v2 and LEED 2009 – Design & Construction as a free PDF download.
If your project uses thermal energy produced from or delivered to a source outside the LEED project building, this document is required reading. Well, we think it's required reading because it's so useful. In fact, USGBC technically only requires it for LEED-NC, CI, CS, or Schools v2.x projects registered after May 28, 2008 (those projects can also continue to use version 1 of this document).
For LEED 2009 projects, the district energy guidance is recommended by USGBC, but is not (yet) formally incorporated into 2009 requirements. (Perhaps we can look for an addenda on this in October 2010.)
The document looks great. Particularly helpful is a section at the beginning that shows what's new in this version. Here are some tidbits:
Changes to Enhanced Commissioning (EAc3)
1. Clarification has been provided regarding system commissioning for district plants that include additions plus existing equipment.
2. Requirements have been changed slightly to align more closely with EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating systems. commissioning requirements.
Changes to Energy Efficiency (EAp2 / EAc1) – Performance Path
1. The modeling protocols that were called “Step 1 and Step 2” in the Version 1.0 guidance have been recast as “Option 1 and Option 2” in the new guidance. Now each project team chooses one of the two performance options to show compliance with both EAp2 and EAc1; no team is required to do both. This is an important change, and is intended to offer LEED customers more flexibility and simplicity.
2. The Combined Heat and Power An integrated system that captures the heat, otherwise unused, generated by a single fuel source in the production of electrical power. Also known as cogeneration. (Adapted from U.S. Environmental Protection Agency)(CHPCombined heat and power (CHP), or cogeneration, generates both electrical power and thermal energy from a single fuel source.) guidance for district energy systems is incorporated into this document. The CHP guidance has also been modified to provide defaults when efficiency values are not available, and to clarify how the energy generated from the CHP plant is distributed between projects.
What do you think of the updated guidance on district energy? Anything that will help or hurt your project? Please comment below.