CHP-equipped district energy: A winning strategy for LEED and PEER

Published on: 
24 Feb 2017
Author: 
Kunal Gulati

On January 18, 2017, USGBC teamed up with the U.S. Environmental Protection Agency’s Combined Heat and Power Partnership to host a webinar highlighting the potential LEED point impact for buildings connected to CHP-equipped district energy systems. In addition, we provided an overview of the PEER rating system for sustainable energy systems.

The webinar focused on how buildings connected to district energy systems can earn points in the LEED for Building Design and Construction: New Construction and Major Renovations rating system and how LEED recognizes the energy efficiency benefits of CHP-equipped district energy systems. Future PEER developments that will further streamline the process for achieving LEED points with CHP were also discussed.

If you missed the webinar, you can still check out the recording and the full presentation.

In addition, our FAQs below may answer your questions about this topic. PEER is the world’s first rating system for electricity generation, transmission and distribution. Contact us to inquire about your project.

Frequently asked questions

Q: Where can I find more information?

A: For more information, see also the following resources referenced in the presentation:

Q: Can the methodology for awarding LEED points to buildings connected to a CHP-equipped DES be used for a DES that utilizes both CHP and boilers?

A: Yes, the methodology accounts for CHP-supplied power and heat that is distributed from the central plant to the connected building, as well as any onsite production of thermal and purchased power. The methodology can also be used if there are supplemental boilers in the central plant in addition to the CHP system.

Q: Is CHP only for residential buildings?

A: No, CHP can be used for many different building types. See the EPA CHP Partnership website to learn more.

Q: Does the central plant have to be modeled on an hourly basis, or is an annual overall generation profile sufficient to calculate the annual energy cost?

A: The LEED Treatment of District or Campus Thermal Energy in LEED v2 and LEED 2009 Guidance outlines several possible approaches for modeling the annual performance, depending on the energy rate structures and the complexity of the system itself.

Q: How would a campus that is currently developing a DES approach the LEED certification?

A: There are two opportunities. First, buildings connected to the DES have the opportunity to become LEED-certified. Connecting to a CHP-equipped DES will greatly enhance the opportunity for those buildings to earn points. Second, the DES as a whole can also be certified under PEER, which will also produce benefits for individual buildings connected to it.

Q: Do CHP-equipped district energy points also apply to LEED ND?

A: Today’s presentation was focused on LEED BD+C, and to some degree, LEED O+M; LEED for Neighborhood Development has a slightly different approach to earning points with DES. See LEED ND Green Infrastructure and Buildings Credit: District Heating and Cooling for more information.

Q: In our region, district energy steam costs far more than on-site-produced steam or hot water. Benefits are not energy-cost reduction, but no need for mechanical equipment and maintenance. How does this relate to LEED points?

A: LEED points are determined by energy cost savings. The cost that an individual building pays for steam is different than the cost to generate the steam, which is the basis for the LEED point calculation.

For PEER, the DES is benchmarked on environmental metrics (e.g., system energy efficiency). However, the PEER contribution is still based in part on the percentage of the LEED building’s total energy (expressed as cost) that is provided by the DES.

In general, USGBC is piloting metrics other than cost to evaluate energy performance. See Pilot Credit: Alternative Energy Performance Metric for more information.

Q: We have CHP that serves the campus, but the CHP provides 100 percent thermal and only 60 percent electric. We also have standby boilers that serve the campus; how will this be considered?

A: PEER relies on one year of data (either operational or modeled) to assess the system performance. The extent to which standby boilers were used over that year is the extent to which they would figure into the PEER performance.

For LEED, the PEER contribution is based on the percentage of the specific building’s load (electric plus thermal) that is met by the CHP.

Q: Is there any guidance for existing building connecting to a new CHP/DES?

A: The guidance provided in today’s presentation applies to new and existing buildings connected to a DES. Additional guidance for existing buildings can be found in the LEED v4 O+M Reference Guide.

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