ASHRAE Journal - August 2021 - 8

LETTERS
Net Positive
Home Retrofit
" Home Retrofit Results in Net
Positive Energy Operation " in
June's ASHRAE Journal by John
Suzukida; Daniel Bacellar; Reinhard
Radermacher, Ph.D., Fellow/Life
Member ASHRAE, is a well documented
case study that includes
useful information so readers can
understand the engineering that
supports the project. However,
it describes an unsustainable
approach to net zero design.
It does not mention storage, so it
seems to be yet another example
of net positive/net zero buildings
that use the grid for balancing. This
is a euphemism for the idea that
net zero customers rely on nearby
energy " pigs " to use solar electricity
that the net zero customers generate
during the day but cannot use at
that time. Net zero customers still
need nearly the same capacity and
energy from the grid they would
need without their solar cells to
light and heat their buildings during
the cold, dark hours of winter.
I cannot help concluding that
under the prevailing wisdom for
net zero design, if everyone were to
try to be net zero, no one could be.
What am I missing?
Kenneth M. Elovitz, PE, Fellow ASHRAE
The Authors Respond
This initiative is a work in process,
with storage to come, but practical
realities dictated not doing
everything at once. Electrification,
reducing energy consumption using
heat pumps, generating power with
solar PV and the use of a charging
station for an electric vehicle (EV)
represent one model of the future.
Cost-effective storage, including
potentially using the EV for storage
and real-time pricing coordination
with the utility, are potential next
steps. In the meantime, we thought
it may be helpful to share what's
possible with available technology.
Clearly, the manner by which we
use energy in the future will need to
be all-encompassing and systemsoriented.
Utilities, consumers, et
al., each will have roles that result in
net zero carbon in total and not just
focused on net zero energy at a site.
John Suzukida, St. Paul, Minn.; Daniel Bacellar, College
Park, Md.; Reinhard Radermacher, Ph.D., Fellow/Life
Member ASHRAE, College Park, Md.
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ASHRAE Journal - August 2021

Table of Contents for the Digital Edition of ASHRAE Journal - August 2021
