Figure 1:Inflorencent strobe lights retrofitted
Page data
Part of RCEA energy audit reviews
Engr115 Intro to Engineering
Type Project
Keywords Energy, energy audit
SDGs Sustainable Development Goals SDG07 Affordable and clean energy
Authors Daniele Peters
Jamielee Larrabee
Published 2009
License CC BY-SA 4.0
Affiliations Redwood Coast Energy Authority
Humboldt State University
Page views 31
Location data
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Location California, USA

   Thomas J McMurray, founder of McMurray's roofing company originated in Des Moines Iowa in 1919. Twenty nine years later his company expanded across the country to Eureka, California! Eureka is a very rainy place so the roofing business absolutely boomed making the McMurray company one of the main employers of the area.

   The Eureka location has multiple buildings where they work with various amounts of equipment such as: power tools, computers, lights etc. The buildings that were retrofitted include: the office building, auto shop, metal shop, and the storage warehouses. Lighting is a minuscule consumer of energy compared to other appliances used at the McMurray location. However, the retrofit saves them $1200 a year on electricity. As seen in Figure 2 McMurray's energy consumption decreased after the retrofitting.
McMurray & Sons Roofing

The Retrofit[edit | edit source]

RCEA[edit | edit source]

The Redwood Coast Energy Authority is an association seeking to make communities as energy efficient as possible. Their mission is to innovate resources to reduce the amount of energy used by the county. RCEA receives funding through government grants and donations which supply energy resource technology to Humboldt County. The RCEA website describes numerous affordable programs for both residential and commercial properties.

The RCEA provided the retrofit for the McMurray roofing company. Troy Bean, branch manager at the Eureka location, recalls a pleasant experience: "Fast and easy, wish I would have known about these guys sooner!" At the time Bean was not looking for a retrofit and would not have conducted one if the RCEA had not approached him. However, he recommends a retrofit to anyone wanting to save "big" money on their next energy bill.

Figure 1a: Retrofits to fit all size light bulbs

CFLs[edit | edit source]

A retrofit is the replacement of new, more efficient, technology from old outdated technology, usually through lighting (Figure 2).

Figure 2: 1 CFL inflorescent = 9 incandescent light bulbs

The retrofit for McMurray and Sons included replacing all incandescent bulbs with CFLs. Also, several conventional light switches were converted to sensor switches.

After the Retrofit[edit | edit source]

After the retrofit, the employees of the company became aware of their energy consumption. In order to conserve energy the employees began turning off lights in rooms that were rarely used and when leaving a room. This retrofit affected more than just the McMurray buildings: employees report to have become more energy conscience at home as well.

Savings & Analysis[edit | edit source]

Table 1: Savings
Savings Estimated Actual
Yearly Bill $2,449.29 $1200
CO2 Emissions 8,323 lbs/yr 5,722 lbs/yr
Kilowatt Hours 14,687 kWH/yr 10,920 kWH/yr
Payback Time 1.5 years 3 years

The retrofit took place in March of 2008. The total cost was $3,669.83 As presented in Figure 2, the energy consumption varies from month to month and does not follow a set pattern. Overall, the graph has a downward trend which implies a decrease in energy usage. Zooming in on the months directly before and after the retrofit, a decrease in energy use is visible. During the three months prior to the retrofit the company's energy usage was above 3500 kilowatt hours (KwH). After the retrofit energy usage decreased by over 500 KwH per month and continued to fall. Table 2 exhibits the decrease in monthly energy bill from 2007 to 2009. After the retrofit in March 2007 the energy consumption decreased.

Fig 1: Complete energy consumption over a 3 year period, arrow indictates the retrofit which took place in March 2008

Table 2: Energy

Year KwH Monthly Bill ($)
2007 3172 499.05
2008 3085 487.09
2009 2839 468.01
















References[edit | edit source]

  • Humboldt State Engineering webpage (2009). Retrieved from: HSU Engineering Dept
  • Redwood Coast Energy Authority (2009). Retrieved from: RCEA 
  • Redwood Coast Energy Authority. (2008). Customer Report: McMurray and Sons
  • Retrofit Technologies (2009). Retrieved from: Retrofitting
  • Pacific Gas and Electric Company (2009): PG&E

Special Thanks to: