discovered in schools, offices, hotels and other
commercial buildings across the country.
In terms of energy savings and economic
stability, the business case for energy-efficiency
upgrades is clear. How many other investments
these days provide double-digit rates of return
and a hedge against rising energy prices — not
to mention the ability to conserve resources,
mitigate climate change and create local jobs?
And as sexy as a new PV system might be, any
energy engineer will tell you that efficiency
and conservation come first. The smaller your
energy needs, the smaller the PV system you’ll
need and the smaller the upfront investment.
Meanwhile, every energy improvement accrues
savings that can be used for the next efficiency
or renewable energy project. After all, a kilowatt-hour saved is a kilowatt-hour earned.
Many commercial buildings hold a treasure
trove of efficiency opportunities. For significant
and lasting effects, there are no one-size-fits-all projects or technologies, but there are
some time-tested approaches. Energy costs
are true business cost centers that can pay
dividends when approached strategically and
systematically. The following are six steps to
guide energy-efficiency efforts.
1. Assess Your Building’s Performance.
Establishing a benchmark of how much
energy a building uses is critical for two reasons.
First, knowing how the building compares with
similar buildings provides an idea of just how
much potential exists. Secondly, tracking the
effectiveness of efforts over time provides invaluable feedback and a sense of accomplishment.
Without benchmarking, efficiency efforts are a
shot in the dark.
The traditional utilities-cost-tracking method
is to enter bills from all of the building’s energy
utilities into a spreadsheet each month. Lately,
more utility companies offer this basic tracking
through an online account.
To take it a step further, one can compare
energy consumption in similar buildings by
converting the kilowatt-hours of electricity and
therms of gas to a common unit of measurement
such as a thousand British thermal units (kBtu)
and summing them. The total annual site energy
intensity is then calculated by dividing the total
building energy by its square footage to arrive at a
universal metric such as kBtu per square foot, per
year. Large building-fleet managers use software
tools designed for this comparative analysis.
Using this area-normalized metric, buildings
An energy audit, like a financial audit, tracks and documents each incoming energy source to its final
destination. Power measurements, equipment levels, light levels and other data are detailed and categorized. A good audit must also assess the soft side of consumption — management policies, building
operations and occupant habits.
of different sizes can be compared. But how does
one account for other variables that affect energy
consumption, such as climate zone, occupancy
and operating hours? For example, a high-efficiency office building operating 75 hours per
week may have the same site energy intensity as
a low-efficiency building that runs only 55 hours
per week. The Environmental Protection Agency
(EPA) Energy Star program for buildings was
created to account for these variables.
The Energy Star program builds on data
from a national survey of facilities called the
Commercial Buildings Energy Consumption
Survey. Statistical analysis weighs each of these
variables to arrive at a common metric, an
Energy Star rating. Currently, it uses the 2003
survey data comprising a sample of 5,216 commercial U.S. buildings. The program is accessed
through the EPA’s free tool, Portfolio Manager,
which allows one to enter utility bills and facility details to obtain an Energy Star rating from
0 to 100. A score of 50 is average, and a score
of 75 or higher is eligible for an Energy Star
label. (See a sample report on page 58, or visit
tinyurl.com/2o96hn.) The Energy Star rating
benchmarks the starting point, gives an idea of
improvement potential and tracks effectiveness
as the score rises over time.
The next step of assessment is to target
exactly where, when and how the energy is
being used throughout the facility. An energy
audit, like a financial audit, tracks and documents
each incoming energy source to its final destina-
tion. Power measurements, equipment labels,
schedules and settings in the building automa-
tion system, light levels, temperatures, pressures,
flow rates, window characteristics and other data
are carefully detailed and categorized. A good
audit must also assess the soft side of energy
consumption — management policies, build-
Every energy improvement
increases the comfort of
your building’s occupants
while accruing energy
savings toward the next
ing operations and occupant habits. A holistic
and collaborative energy audit provides a strong
foundation of data for the analysis.
2. Analyze the Opportunities.
The raw data of the energy audit is now analyzed to find the best opportunities for improving
energy efficiency. Often called energy conservation measures (ECMs), these are frequently
classified as no/low cost, budgetary and capital