Imagine you are Willy Wonka, and it is time to build a new factory. You would like the new factory to be as energy efficient as possible, while still producing as many great-tasting Wonka Bars as you can. Food
and beverage manufacturing facilities typically
are huge energy consumers with annual bills
in the realm of 5-10 percent of the facility’s
construction budget, or in absolute terms, in the
multi-million dollar range.
Operational savings are a critical component
of the food and beverage industry business
model. By estimating projected energy use for
the project, identifying areas for energy reduction and implementing the best return on investment energy efficiency measures, substantial
cost reduction can be gained while maintaining
the quantity and quality of the product produced.
What are the special characteristics of
food and beverage manufacturing facilities
that set them apart from other higher energy
use building types?
Unlike general manufacturing and other
heavy energy use building types, most food and
beverage manufacturing plants produce some
type of custom product that has a proprietary
formula (aka Everlasting Gobstoppers) and hence
uses special equipment. This specialized nature
can make it difficult to identify where to capture
energy and energy-cost savings.
In addition, engineers, vendors and specialist
integrators are in charge of designing different
pieces of the processing plant – such as raw
product receiving and storage equipment; equipment and utilities for the manufacturing process;
packaging, heating, cooling and refrigeration
systems; and the basic shell of the manufac-
turing plant. Any alteration to improve the effi-
ciency of one portion of the plant can affect the
performance of the upstream and downstream
equipment. Finally, these plants are built only
every few decades, when company production
increases enough to warrant a new facility. This
timeline does not allow a lot of space for incre-
mental improvement or test-and-adopt scenarios
that are used in commercial construction.
Given these complexities, what is a good
key performance indicator (KPI) to predict
and measure energy performance?
From experience, we know absolute energy
use reduction is not a good performance indicator for food and beverage facilities. Comparing
overall energy use to other facilities does not
tell the whole story because each facility is
different, and built so far apart in time and technology, that it would be impossible to establish
a baseline energy performance standard on top
of which energy improvements can be applied.
Unfortunately, most green building rating systems and energy benchmarking frameworks use
traditional absolute energy efficiency achieved
by the facility, and in some cases energy use per
square foot, to establish energy performance.
We have found that the best KPI for food and
beverage manufacturing facilities is energy cost
per product: the cost of the energy required to
produce one unit of the product, such as energy
cost to produce one pound of coffee, or energy
cost to produce one packet of cookies.
Energy cost per product is easily measurable
and the owner understands it well because it
ties back into the high-level cost per product
they track for profitability. Also, the KPI allows
comparison versus the energy efficiency of other
products within the same facility, against the
energy performance of an existing facility and,
if data is available, even against the energy
performance of a competitor’s facility or a competing production technology. This KPI also helps
establish energy improvement capital expenditure (CapEx) as a dollar amount saved per
product KPI, which allows comparisons against
other cost reduction measures across the supply
chain such as improvements in transportation or
Finally, and most importantly for the purposes
of tracking and driving energy performance, this
KPI allows the design team to quickly establish
a baseline, as the client or owner has already
established the cost of what it takes to produce
the product (total cost per unit product).
Is there a good methodology one can use
to calculate the energy cost per product?
Trying to nail down how much energy will
be consumed, and how much product will be
produced, before the first Everlasting Gobstopper
rolls out of the factory may seem like a daunting
task, but with a bit of organization and a good
project team we can achieve a reliable estimate.
The following is a process that has been used
many times to calculate the energy use cost for
highly complex food and beverage facilities.
Step 1: Identify key designers for different
pieces of the project design. Typically, the key
players we need information from include the
mechanical designer, architect, the process
designer for the project, the refrigeration systems designer, the electrical engineer, and the
process designer from the vendor side if there
are any custom packaged processing equipment.
Step 2: Obtain and track the energy performance and operation metrics of each system
in the project. This may include the energy
demand, hours of operation, diversity in load,
part load conditions and system efficiencies for
each piece of cooling equipment, fans, motors,
Step 3: Collate the demand and performance information collected in Step 2 and calculate the annual energy use for each system,
and then combine to calculate the energy use for
the entire facility.
For systems that interact with the environment — such as the chillers and air conditioning
equipment for space conditioning — and are
affected by weather conditions and people and
equipment dynamics in the space, use an hourly
simulation energy modeling software to predict
annual energy use.
For more standalone systems where energy
use is driven purely by production schedule and
By Thulasi Narayan, LEED AP and Grey Fowles, CDT, LEED AP
Energy Efficiency May be
Your Factory's Golden Ticket