Enhanced automation has helped Hewlett-Packard achieve $1.5 million in annual energy savings

Enhanced automation has helped

Hewlett-Packard achieve $1.5 million

in annual energy savings.

ith the onset of California’s energy crisis, Hewlett-Packard

Company (HP) wanted to be doing more to save energy

and to help avert rolling blackouts in their community. HP

enhanced its existing energy management system at its Roseville,

California campus by adding a greater level of automation, which

allows them to cut peak load by about 12 percent without jeopard-

izing occupant comfort or productivity. In fact, enhanced automation

has helped HP to maintain 1996 energy levels and save on energy

costs, despite growing their business.

CASE STUDY

SUMMARY

Enhanced automation

was used to expand the

capability of HP’s energy

management system to

automate lighting as well

as HVAC control.

Participant:

Hewlett-Packard

Company

Building Type:

Office campus

Site Size:

1.4 million ft

/6,100

occupants

Project Cost:

$275, 000

Project Incentives:

$212, 000

Primary Benefit:

Energy cost savings

A success story from the

CALIFORNIA ENERGY COMMISSION

Enhanced Automation Case Study 2

HVAC & Lighting Controls /Office Campus

pg_0002

Hewlett-Packard (HP)

Company facility operators

had been optimizing the

campus’ energy use for

many years. However, with the onset of

California’s energy crisis, HP wanted to

be doing more to save energy and to help

avert rolling blackouts in their community.

Their energy management system (EMS)

had limited automation: cutting back

on HVAC and lighting loads was labor-

and time- intensive, involving the manual

adjustment of several controls spread

out over the vast campus. Such a system

did not allow them the flexibility to

curtail load and still maintain occupant

comfort, a high priority at HP.

The availability of funding from the California Energy Commission for the

installation of enhanced automation technologies served as a catalyst for HP

to move ahead with plans to modify the automation capability of their EMS.

HP traditionally used its EMS for monitoring temperatures and for operating

air-handlers and other mechanical HVAC equipment. However, control over lighting was limited.

Adding the desired level of automation involved linking the EMS to all lighting and HVAC

systems via direct digital controls (DDC). Roseville Electric, HP’s municipal electricity supplier,

secured and administered the California Energy Commission grant funds and played a key

role in shaping and implementing the project.

The project was a

resounding success.

We discovered very

quickly that we could

curtail demand any

day of the year, and

we did. Our historical

peak was 10.9 MW

and we were routinely

able to reduce that to

about 9.5 MW, saving

us not only energy,

but demand charges

as well.”

“

As utilities move toward time-of-

use metering, a business’ ability to

control utility costs by automating

energy use according to price will

become increasingly valuable.”

“

Before, in times of power shortages,

we would curtail by manually shutting

off selected circuit breakers. Now,

our enhanced energy management

system automates this process, saving

our staff valuable time and effort.”

“

Steve Eymann,

HP Facilities Engineer

More precise

control of loads

Automated control

of HVAC and

lighting systems

Labor- and

time-intensive to

shed load

Inability to curtail

energy use and

still maintain

occupant comfort

Unpredictable

energy supply

SOLUTION

PROBLEM

kW Aug 7–9 kW Jun 19–21

10,000 kW

8,000 kW

6,000 kW

4,000 kW

TUESDAY

WEDNESDAY

THURSDAY

The above graph shows the demand curves for two

weeks with similar temperature profiles. Demand

reduction was implemented on Tuesday, Wednesday,

and Thursday of the second week in August (blue line).

Comparison of the two curves shows that demand

was reduced by 0.5 MW to 1.0 MW, as shown in the

shaded areas.

HP Roseville Electrical Demand

pg_0003

As a result of these changes, HP is now able to shed up to 1.5 MW of peak

load, without disrupting occupants’ productivity or comfort. Originally intending

to operate their new load-shedding strategies under emergency situations only,

HP found that they could actually benefit from using them on a day-to-day

basis. Due to their conservation efforts over the past eight years, HP Roseville is currently

saving $1.5 million annually.

Enhanced automation allows HP to program a not-to-exceed

setpoint for electrical demand and instruct the EMS to initiate

pre- programmed load shedding strategies when that setpoint

is approached. The system is able to monitor the effects of

these strategies on overall demand throughout the day and to

make continual adjustments so that the demand is kept just

below the setpoint.

Direct control over mechanical HVAC equipment allows HP

to operate their systems efficiently. Facility operators can now

adjust zone temperatures based on actual, real-time occupancy

levels. For instance, if operators know that personnel in one

section of a building will be assembled in a conference room

for three hours on a summer afternoon, they can operate HVAC

equipment so that temperatures are higher in the emptied

building section and lower in the crowded conference room.

BENEFITS

Automated

load shedding

Increased

occupant comfort

Targeted

HVAC control

Energy cost

savings

PROJECT SITE DESCRIPTION

Location:

Roseville, California (16 miles

northeast of Sacramento)

Size:

10 buildings occupying

1.4 million ft

Space Function:

Research and development,

design, engineering, manufac-

turing, testing, customer

support and sales

Number of Occupants:

6,000

Site Contact:

Steve Eymann

HP Facilities Engineer

Energy Usage

Summer Peak Demand

10.9 MW

Curtailable Demand

1.5 MW

Equipment Installed

DDC modules

sensors

High speed data line and

Ethernet communications card

Project Cost

$275,000

Project Incentives

$212,000

pg_0004

Technical Information

P’s enhanced automation project involved expanding the capabilities of existing

systems: A Siemens APOGEE

energy management system, a high-speed local area

network, direct digital controls (DDC), and Square-D PowerLogic

power monitors.

The modifications included mainly software programming of the EMS, along with

some new hardware and wiring. The result is a powerful building automation system

that can maintain demand setpoints without disrupting occupancy comfort.

To monitor the real-time effects of load-shedding strategies on overall demand, HP

linked its electric utility meters to the APOGEE system via existing Square-D

PowerLogic monitors that were attached to the meters. The system now collects and

archives 15-minute interval data. This linkage allows facility operators not only to see

the immediate effects of load-shedding strategies, but also to program their EMS to

reduce campus-wide demand to a specified kW amount. The EMS will now shed

loads in a pre-determined sequence until demand reaches the setpoint.

This pro-

gramming

was made

possible by

the addition

of both

automated demand control ventilation and lighting controls. To implement demand

control ventilation, CO

sensors were installed to ensure that air quality levels remain

above standard as outside air volume changes. The EMS was also programmed to send

digital signals to gradually close hundreds of variable-air-volume terminal boxes and

control valves to reduce the use of chilled water for space cooling. Chillers and pumps

in the central chiller plant respond to the reduced demand for chilled water as they

would to normal reductions in cooling demand. Variable frequency drives on chilled

water circulation pumps slow the pumps to reduce the circulation in the secondary

chilled water loop, and the load on the chillers is reduced until the chillers shut down.

HP’s lighting system was also enhanced with new controls. HP installed multiplexers

to lighting control panels in six campus buildings. The EMS is programmed to shut

off pre-determined, non-essential lights whenever load reduction is needed. Following

the curtailment, the EMS automatically returns lighting to normal levels.

HVAC Controls

Schematic of Hewlett-Packard System

Meter

UTILITY SERVICE

ENTRANCE

CAMPUS-WIDE

DEMAND (KW)

DIGITAL SIGNALS

Lighting Circuits

DIGITAL SIGNALS

EMS

adjusts controls

as demand

approaches kW

set point

TAKING THE NEXT STEP

Free resources are available from the

California Energy Commission.

Business Case Guidebook

Technical Options Guidebook

Contractor and Vendor Lists

Technical Assistance

Case Studies

Alameda County

HVAC Controls/

Government Facility

Comerica Building

HVAC and Lighting Controls/

Large Office Building

Foothill-De Anza

Community Colleges

HVAC and Lighting Controls/

College Campuses

Staples, Inc.

HVAC and Lighting Controls/

Retail Chain

Doubletree Hotel

Sacramento

HVAC and Lighting Controls/

Hotel and Convention Center

further information:

1-866-732-5591

enhancedautomation@xenergy.com

www.ConsumerEnergyCenter.org/

enhancedautomation

Additional Resources

California Energy

Commission

www.energy.ca.gov/

peakload/index.html

Cash for Kilowatts Web site

www.energy.ca.gov/peakload/cash_

kilowatts.html

(also for 50-200 kW demand)

Your local utility

www.sdge.com/business/drp.html

www.pge.com/003_save_energy/

003b_bus/index.shtml

www.sce.com/sc3/002_save_

energy/002i_load_redn/default.htm

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