Realizing Energy Efficiency Opportunities in Industrial Fan and
Pump Systems
R. Neal Elliott and Steven Nadel
April 2003
Summary
Fans and pumps account
for more than a quarter of industrial electricity consumption nationally.
Six industries represent 84% of the potential industrial fan and
pump energy savings: chemical manufacturing; paper manufacturing;
petroleum and coal products manufacturing; mining; food manufacturing;
and primary metal manufacturing. Optimizing the operation of these
fans and pumps could achieve electricity savings ranging from 20
to well over 50%.
While a range
of efficiencies exist for fans and pumps, the opportunity exists
less with increasing the efficiency inherent in the equipment and
more with increasing the efficiency of the application of the equipment.
Part of this potential results from the fact that fan and pump energy
use varies as aproximately the cube of motor speed. In matching
the pump and fan characteristics to the process requirements, the
target is achieving the lowest flow, and thus the lowest energy
usage. A number of approaches can be used to accomplish this, with
the optimal approach depending upon the particular circumstances.
Knowing the process requirements is key to determining the correct
speed of pumps and fans. While this is not a complex engineering
problem, it requires familiarity with both the facility processes,
and fan and pump system design. Most optimization projects involve
greater engineering costs than equipment costs. The average payback
for a good optimization project is about 1.2 years, with the cost
of saved energy on the order of $0.012 per kilowatt-hour (kWh).
These estimates do not account for productivity gains known to exist
at many of the sites, which are sometimes as much as two to five
times the energy savings.
While the potential
for fan and pump system efficiency has long been realized in the
engineering community, attempts to design energy efficiency programs
to capture this potential only date back just over a decade. To
date, these programs have struggled to balance the needs for site-specific
engineering services with program costs, though interest remains
high among mature industrial programs in developing program strategies.
Since the biggest
challenge has been high program cost for opportunity identification
and solution design, it is important that programs quickly focus
their efforts on sites likely to result in implemented savings.
Programs focused on a few specific industries appear most effective.
Programs will need to assemble a toolkit from the extensive existing
materials, and identify key local and North American consulting
resources that can provide assistance. Under this program approach,
there will be limited need for equipment incentives because of the
high benefit-cost ratio for most projects. The more important focus
should be on incentivizing the engineering service, since once a
project is designed the customer is likely to proceed with implementation
if it can be shown to be profitable.
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19 pp., 2003,
$16.00, A034
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