Student Presentations: June 8, 2011
Autonomous Monitoring of Energy Efficiency
Jeffrey Mehlman
Incredible amounts of time and ”energy” have been invested in what to do for the future
generation of ”smart buildings:” new college campuses, new office buildings, new homes. But
there is a huge number of existing structures which have been standing for many years - old
ones with plenty of life left in them. And herein lie the central questions: How do we bring
energy innovations from the past 10 years to this market? With which technologies should we
retrofit existing buildings? What are reasonable ROI expectations? If nothing else, the seminar
presentations this quarter have shown us how difficult it is to integrate energy efficient technologies
into new buildings; starting from a totally clean slate. It will be far more difficult to bring
these technologies into buildings which are already online and saddled with old, yet functional,
equipment.
The current approach for retrofitting buildings with energy efficient technology involves consulting
with energy efficiency firms or contracting with an Energy Services Company (ESCO).
These consultants make money by suggesting and/or installing efficient technologies, guarranteeing
a certain amount of energy savings, and taking a percentage of these savings. When the
consultants come in, they take a ”snapshot” of the energy performance of the buildings and
then make recommendations for better efficiency - grabbing the proverbial ”low-hanging” fruit
for efficiency improvements.
With all of the technology available today, this seems like a 20th century approach for a 21st
century problem. Additionally, it is a fact that many of these so called efficiency ”improvements”
degrade significantly over the first few years of operation and perform only marginally better
than the equipment they replaced (the same goes for new building equipment as well). I argue
that the true path to long-term energy efficiency in all buildings - new and old - begins with
finely-grained energy monitoring. If we can track building performance on a daily basis, we can
see degradation and failures as they occur and suggest the right improvements or repairs at
the right time. This is as opposed to the current approach of taking a ”snapshot” of the energy
profile of a building, making changes, and then effectively walking away for a year or two.
At the end of the day, it turns out that energy flows into buildings in only a few ways and
electricity makes up the lion’s share. Additionally, the heaviest energy consumers in a building
tend to be large pieces of equipment which are on their own, dedicated circuit breakers. This
provides an excellent, low-cost path to acquiring fine-grained energy monitoring at the circuit
level. The technology which is necessary to monitor energy at a circuit level is both available
and relatively low-cost, so it is only a matter of time until systems which collect this data are
available. As circuit-level energy data monitoring comes online, the research questions are: how
can we best make use of finely-grained energy data? When should equipment replacements or
repairs be suggested? The value of this information entirely decided by the consumer - most
likely the facility manager or building owner - so what is the best way to present the information