MRW ENERGY MANAGEMENT
Affordable Energy Savings Solutions That Make Sense



Case Studies

Case Studies

Energy Savings Analysis Washington Arena
Savings Analysis		 Texas Ice Rink Testing
Data and Analysis 

Energy Savings Analysis for an
Oil Company in Cody Wyoming
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Pumping oil requires constant pumping of water down into a well to displace oil as it is pumped up. This is a critical element of an oil fields operation.

What follows is an analysis of energy consumption for 30 days before and 30 days after installation of a STEMS LLC energy management system for their water wells on fields 28-1 & 28. This analysis is based on power bills from Mountain Parks Electric Inc.

Cost for 30 days Pre-STEMS Post-STEMS Delta
KWH 691.5 575.6 115.90
Average cost per day $43.86 $40.47 $3.39
Average savings per day:     $ 3.39
X 365
Average savings per year:     $1,237.35

The customer pays $.02 per KWH for usage over 400 KWH on these two wells.

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Ice Arena in Washington State
Testing Data and Analysis
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On February 25, 2004 we ran a test of the STEMS energy management system
on the chiller in an Ice Arena in Lynnwood, Washington.
The test results are as follows:

Description Pre-test Without STEMS Post-test With STEMS Amount of Change
Volts 460 460 -0-
Amps 427.42 369.1 -58.32
Power Factor .65 .74 + .09
KVAR (reactive power) 43.43 35.134 -9.162

Volts x Amps x Power Factor x 1.73/1000 = 3-phase KW
460 x 427.42 x .65 x 1.73/1000 = 221.07 KWH
460 x 369.10 x .74 x 1.73/1000 = - 217.36 KWH
Kilowatt Hours savings 3.71 KWH

3.71 KWH x 8766 hours per year = 32,522 KWH annual savings.

At $.07 per KWH, we show an annual energy savings
of $2,276.54 on this one piece of equipment!

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Municipal Ice Arena in
San Angelo, Texas
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On January 22, 2004 we ran a pretest of the energy consumption of a 400 ton Chiller at a Municipal Ice Arena in San Angelo, Texas. February 9, 2004 we ran a post-test with the STEMS energy management system installed. The results are as follows:

Channel Description 1/22/04
Without STEMS		 2/9/04
With STEMS

Delta as
raw data
1 Volts 283.60 282.30 -1.3
2 Amps 289.31 256.98 -32.33
5 Power Factor .87 .93 +.06
6 KVAR 40.342 26.866
 -13.476

Volts x Amps x Power Factor x 1.73/1000 = 3-phase KW
283.6 x 289.31 x .87 x 1.73/1000 = 123.49 KWH
282.3 x 256.98 x .93 x 1.73/1000 = -116.71 KWH
Kilowatt Hours savings 5.78 KWH

An interesting side note:
At 7 AM on 1/22/4 the ambient temperature at this facility was 44 degrees F.
At 7 AM 0n 2/9/4 the ambient temperature at this facility was 51 Degrees F.
With higher ambient temperatures, the cooling load should have been greater on 2/9/4.

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