One Green Power point is provided for
entering into at least a two-year contract
for supplying at least 50 percent of the
building’s electricity from grid-source,
renewable energy that meets the “
Greene” certification requirements of the Center
for Resource Solutions.
LEED-NC Issues for
District Energy
The LEED-NC standard has implications
for district energy providers. Among them:
■ The minimum energy-performance
requirements will tend to reduce heating
and cooling loads.
■ LEED objectives for reducing water consumption may lead to desire to use recycled water for condenser cooling.
■ District energy providers will likely become
involved in fulfilling the commissioning and
ongoing monitoring requirements.
There are a number of aspects of
LEED-NC that could make certification of
buildings served by district energy difficult,
or limit the recognition of the sustainability
benefits of district energy, including treatment of refrigerant conversion, renewable
energy, and combined heat and power (CHP).
There are a number of aspects
of LEED-NC that could make
certification of buildings served
by district energy difficult, or
limit the recognition of the
sustainability benefits of
district energy…
Refrigerants
Refrigerant issues can have a potentially critical impact on district cooling. As
noted above, lack of compliance with the
LEED-NC Ozone Protection prerequisite
could result in failure to achieve any level of
LEED certification. LEED-NC requires zero
use of CFC refrigerants for new building
systems, and a “comprehensive CFC phase-out conversion” (generally within one year)
when reusing existing equipment. Most district cooling systems still using CFCs will
not find it economically feasible to completely phase out their use unless the CFC
chillers are ready for replacement anyway.
Many district cooling systems use
hydrochlorofluorocarbon (HCFC) chillers,
thereby eliminating the potential for the
one-point credit for Ozone Protection.
Renewable Energy
LEED encourages ‘on-site renewable
energy’ with credits for solar, wind and other
technologies implemented within the building. The standard currently does not provide
credit for renewable energy provided to the
building from a district energy system.
Combined Heat and Power
The LEED-NC standard provides no
recognition of the energy-efficiency benefits of CHP energy produced outside the
building boundary.
LEED-EB Issues for
District Energy
As noted above, LEED-EB is now being
finalized to cover existing buildings and
ongoing LEED recertification. The “ballot
draft” of LEED-EB that was released in
September 2004 provides a framework
much like LEED-NC, with several key exceptions: ( 1) Energy Performance is measured
based on the U.S. Environmental Protection
Agency Energy Star Benchmarking Tool
rather than ASHRAE 90.1-1999; ( 2) the
Ozone Protection prerequisite allows the
possibility for continued use of CFC refrigerants if a third-party audit shows that the
simple payback on conversion exceeds 10
years; and ( 3) the Additional Ozone
Protection credit may be obtained with
continued use of HCFC’s with a strict leakage limit.
Opportunities To Address
District Energy Issues
The LEED Multiple Buildings Committee
is developing a LEED application guide
specifically for campus-type settings – educational and corporate – and other situations involving multiple buildings. This guide
is intended to interpret and supplement
LEED criteria to address the benefits that
occur when buildings are integrated through
a district (central plant) system. The campus
application guide is an important near-term
opportunity to address some of the district
energy issues discussed above.
In addition to the application guide for
campus buildings, further evolution of the
LEED standard will provide other potential
opportunities to address issues relating to
district energy. A committee on which I
serve is developing a compliance methodology to address energy performance credit
for CHP. Also, the USGBC has proposed a
revised LEED-NC version 2. 2. The proposed
revision will not constitute a major change
in the standard, but addresses refrigerant
issues and shifts the LEED-NC energy performance measures from ASHRAE 90.1-
1999 to ASHRAE 90.1-2004.
An anticipated LEED 3.0 will be a major
rewrite. It is expected to more fully address
the true environmental footprint of a building and offer an opportunity to more fully
account for the environmental benefits of
district energy systems. A draft may be
developed by mid-2005, with a final version
targeted for 2006.
For Further Information
More information on the LEED program
is available at the LEED page of the USGBC
Web site at www.leedbuilding.org. You may
also direct any questions or issues relating to
the impact of LEED on district energy to me
at the contact information below.
Mark Spurr is legislative
director of IDEA. He is also
vice president of FVB Energy
Inc., a consulting firm special-
izing in district energy and
CHP business development,
engineering and marketing,
with offices in the United
States, Canada and Sweden. Spurr serves on
the Executive Committee of the International
Energy Agency Implementing Agreement on
District Heating and Cooling, including
Implementation of CHP. He may be contacted
by email at mspurr@fvbenergy.com.
Column also available at
www.districtenergy.org/de_magazine.htm
