I sent out an email a few weeks ago about whether people thought we
could use an on-site gas-fired fuel cell in EAc1 (reduces utility
company demand, lowers emissions, etc).
Although we haven't submitted our project this way, nor have we
submitted a CIR, I just noticed at the end of the CHP Methodology
publication that the following requirements exist:
CHP System Qualifications
The intent of this guidance protocol is not to grant performance
advantages under EAc1 to
large-scale utilities, but rather to support and reward the
implementation of smaller scale
CHP installations. Consequently the CHP system must meet the following
criteria in order
to be eligible for consideration under EAc1.
1. The minimum annual CHP system efficiency must be at least 60%.
Efficiency is
expressed by the following equation:
Annual CHP Efficiency = (Annual Btu electrical output of the fuel-driven
electricity
generator + Annual Btu Thermal Product) / Annual Btu fuel input (Lower
Heating Value of
input fuel)
2. The environmental performance of district CHP systems must be
validated by a
narrative addressing emissions and showing that the environmental impact
of the system
is lower than if the building heating requirements were met with a
natural gas boiler and
the cooling requirements with electric chillers using electricity
provided from the local grid.
3. The Design Building must still meet EA Prerequisite 2 without the
benefit of CHP.
In other words, unless we are recovering heat from fuel cells, natural
gas generators, etc, and the total system efficiency is 60%, we CANNOT
take credit for them in EAc1.
Sucks, but I guess there's a valid reason for this (someone could
install a big inefficient diesel generator to shave peak demand, and get
away with lower performing building materials, HVAC systems, etc).
Just wanted to forward this information to everyone.
James Hansen, PE, LEED AP