## Genentech: New Energy Efficient Pharmaceutical Manufacturing Cleanroom Facility[^1]

## Project Benefits Summary

+-------------------------------------------------+--------------------+
| ##### Estimated Annual Energy Cost Savings      | \$552,800/y        |
+-------------------------------------------------+--------------------+
| *Actual Incremental Project Cost*               | \$1,783,360        |
+-------------------------------------------------+--------------------+
| *Utility Incentive*                             | \$842,400          |
+-------------------------------------------------+--------------------+
| *Project Payback (after incentive)*             | 1.7 years          |
+-------------------------------------------------+--------------------+

### Facility Description

The Genentech Vacaville facility is made up of six buildings in
Vacaville California. This is the second site for Genentech, the first
site is located in South San Francisco, CA. Genentech is a leading
biotechnology company that discovers, develops, manufactures and markets
human pharmaceuticals for significant unmet medical needs.

![](media/image1.jpeg){width="3.376388888888889in"
height="2.3673611111111112in"}

1.  180,000-ft^2^ Bulk Manufacturing Building with class 10K and 100K
    cleanroom areas and 10 air handling units (approx. 400,000 cfm)

2.  18,000-ft^2^ Central Utility Plant with 3,400 tons of chilled water,
    3,000 scfm of compressed air, 14,000 gpm of tower water (process and
    HVAC), and 70,000 lb/hr of high pressure steam

3.  40,000-ft^2^ Lab/Administration Building

4.  30,000-ft^2^ Warehouse

5.  20,000-ft^2^ Facilities Service Building

6.  A "spine" connecting all of the buildings together

The energy saving measures for the site were aimed at the entire
facility. However, this study focuses only on measures that affect the
cleanroom areas. In addition to internal production requirements, these
areas are required to comply with Food and Drug Administration (FDA)
regulations for cleanliness because the facility is intended for the
production of pharmaceuticals.

#### Project Description

A total of twenty-two separate energy efficiency measures were performed
at the Vacaville site. These measures are summarized below with a
mention of estimated energy savings. The estimated savings were
calculated by Genentech's energy consultant, Southern Exposure
Engineering based upon baseline and enhanced energy consumption models.
No measured data is currently available for these measures.

*Key aspects of the energy efficiency project*

**[Discharge Air Temperature Reset (Makeup Air Handlers)]{.smallcaps}**

Control logic was implemented to reset the discharge air temperature up
from 55°F to 60°F when the demand for cooling decreases. This leads to a
reduction in energy use because the makeup air is not cooled all the way
down to 55°F. All of the cleanrooms are regulated by the FDA, which
requires that they be supplied with a constant volume of makeup air.
This temperature reduction prevents overcooling and subsequent
unnecessary reheating of the supply air to the space, thereby saving
chilled water and steam plant energy. This measure is expected to have
annual energy cost savings of about \$155,000/y and a reduction in peak
electrical load of about 19 kW.

**[Variable Speed Drives for the Variable Volume Air
Handlers]{.smallcaps}**

Instead of inlet vanes for the supply and return fans, variable speed
drives (VSDs) were installed on the six variable volume air handlers
throughout the building including one serving the cleanroom. The VSDs
reduce the horsepower of the fans to reduce flow, whereas inlet vanes
reduce the flow by increasing pressure drop while the fans are still
running full speed. VSD operation reduces fan motor energy use more than
vanes do at low flow conditions. The annual energy cost savings are
expected to be about \$23,000/y with a reduction in peak load of about
40 kW.

**[High Efficiency Boilers and Boiler Economizers]{.smallcaps}**

High efficiency boilers were installed as well as boiler economizers.
The boiler stack economizers recover waste heat out of the flue gas,
allowing more steam generation using the same amount of fuel. Together
these measures are expected to have annual energy cost savings of about
\$48,700/y.

**[Tower Water for Process Cooling]{.smallcaps}**

Water from the cooling towers is being used for high temperature
processes that do not need the low temperatures provided by the
comparatively less efficient chillers, which operate at 0.5 kW/ton
efficiency, at best. The cooling towers are able to provide cooling at
about 0.04 kW/ton (an order of magnitude improvement in efficiency). The
cooling towers provide 75°F water for processes that do not require 40°F
chilled water such as pasteurizing and cooling for the water for
injection (WFI). This measure is expected to save about \$62,700
annually and reduce peak load by about 455 kW.

![](media/image2.jpeg){width="2.859722222222222in" height="2.15in"}

A dedicated process chiller was installed in manufacturing building to
provide the low temperature processes with 40°F water instead of using
the chilled water from the central utility plant. A surge tank was also
installed for chilled water storage to reduce the peak electric demand.
The surge tank holds 15,000 gallons and provides approximately 600
ton-hours of thermal storage. Large energy savings also come from this
separation of low temperature loads from the higher temperature loads.
This allows the central plant to operate at 44°F, instead of 40°F,
resulting in a significant improvement in its efficiency. The low
temperature chiller and surge tank are expected to save about 152,000
kWh annually and reduce peak loads by about 560 kW, results in cost
savings of about \$36,000/y.

**[High Efficiency Equipment and Unequal Chiller Sizing]{.smallcaps}**

A high efficiency process chiller and high efficiency central plant
chillers, vacuum pumps, and motors were installed. In an effort to
operate the chillers as close to full load as possible, where they are
most efficient, a 600 ton chiller and two 1,400 ton chillers were
selected instead of three 1,134 ton chillers. This unequal sizing method
saves energy by allowing the chillers to stage up in smaller steps and
operate much closer to full load. The two large chillers are run at full
load while the smaller one can be run to supply any additional cooling
that is needed. By selecting high efficiency equipment and unequal sized
chillers, about \$113,250 will be saved annually with a reduction in
peak load of 296 kW.

**[Low Approach Cooling Towers]{.smallcaps}**

Large cooling towers were installed to reduce the approach from 14°F to
8°F above the design wet bulb temperature of 71°F. In addition, the
spray nozzles were reconfigured to spread the condenser water more
evenly over the fill while allowing the flow to better match the
required flow for the chillers. This
![](media/image3.jpeg){width="3.297222222222222in"
height="1.6743055555555555in"}kW/ton (0.013 kW/ton per °F decrease in
condenser water supply temperature). This measure is expected to save
about \$24,000 annually with a decrease in peak load of 70 kW.

**[Pump Variable Speed Drives]{.smallcaps}**

VSDs were installed on the condenser water pumps, primary chilled water
pumps, secondary chilled water pumps, tertiary chilled water pumps, and
heating water pumps. The VSDs save energy by precisely matching the flow
and the pressure requirements of the system to minimize pump energy.
These drives will save approximately \$36,900 annually and will reduce
the peak demand by 140 kW.

###### Applicability to the Cleanroom Industry

These efficiency measures have not inhibited Genentech from complying
with strict FDA regulations for pharmaceutical plants. The plant it is
expected to operate and more reliably with these modifications and,
because the project had an excellent payback of 1.7 years, after the
utility incentive, it will be more profitable to operate in the long
run. One example of improved reliability is the surge tanks, which
guarantee that process chilled water will be available when needed in
case of a shutdown.

Part of the reason that this project was so successful was that the
measures could be implemented in the development phases of the plant
before any equipment was purchased or installed. Energy efficiency
measures implemented in a new building can achieve greater and more
cost-effective savings than retrofit measures implemented in existing
buildings.

###### Project Challenges

Genentech encountered a number of challenges while trying to implement
energy saving measures for this project. In a concerted effort to
maintain the goal of efficient operation, Genentech worked through
solutions to most problems they encountered. Some of these problems are
common in the cleanroom industry and their solutions should be
instructive for other facility operators and planners. The first problem
was that no review period was scheduled for analysis of the energy
saving alternatives. These reviews were to be included in the overall
design review period, where they would probably fall through the cracks.
To solve this problem, the energy consultant was integrated with the
design team to provide quick feedback on ideas and recommendations to
improve energy use during the design process. Secondly, no defined
budget was allocated for development of energy saving ideas at the
beginning of the project. However, money for actual projects was
included in the overall project budget. The solution was to obtain
utility funding for idea development and analysis and with utility
incentives for ideas that resulted in a payback of greater than two
years. A third challenge to successfully capturing the savings from
energy efficiency measures lies with the building operations staff. This
is being addressed through education, training and awareness of the
original design intent.

[^1]: Based on "Recommendations Report, Volume 1 of 2, Genentech, Inc.,
    New Facility, Vacaville, CA." Prepared by Southern Exposure
    Engineering and Pacific Gas and Electric Company; November 21, 1997.