The lights are on, but nobody’s home: installing motion activated lights for UW communal areas

Executive Summary:

Many of us will have noticed that the lights in communal areas of UW buildings often get left on even after the last person in the area has left. This wastage is likely to occur overnight, at weekends and over holidays.  We propose to install motion activated light switches in the corridors of 6 floors of the Atmospheric Sciences building (ATG Building), which will switch off automatically after a specified amount of time if no motion is detected. If someone walks into the area then the lights will switch back on in that area. We present a solution based on switches and sensors that communicate wirelessly, which eliminates the need for extra wiring to connect the motion sensors and the lighting circuit. The technology is well-proven and installation is straightforward.

Several environmental problems stem from electricity wastage. Washington State generates most of its electricity from hydroelectric power. Therefore, the energy savings from this project will help improve stream and river flows for endangered species such as salmon. The electricity savings are likely to have a significant future environmental impact since reduction of electricity usage at the point of use is recognized as one of the most effective ways of scaling back energy generation requirements at the power plant level due to the large loss of energy in transmission. With a growing population Seattle will need to increase efficiency in order to meet future needs using renewables.

We estimate that our scheme could prevent over 16,000 kWh of electricity usage annually, which is enough to power a student bedroom (approximated at 3 kWh per day) for almost 15 years. This wastage costs the university almost $1000 a year, which is money that could be used in productive ways. Scaled to the whole campus the wastage is very large indeed. We intend to install light monitoring devices that will enable us to log when the lights have been turned off by the system and thus allow us to quantify the exact amount of electricity saved and also to estimate any potential effects of switching on the lifetimes of the bulbs.

The estimated cost of the project, including materials, labor, taxes, advertisement and outreach costs is $7775.74. However, we calculate that due to the electricity savings, the full project costs will be recouped after only 8 years. If considering only materials and labor (i.e. without outreach, etc. costs), this is reduced to only 6.1 years.

The project will be led by Dr. Daniel Grosvenor (UW research Associate, Atmospheric Sciences) and Prof. Robert Wood (faculty Associate Professor, Atmospheric Sciences). They will also act as student mentors for 3-4 students who will be involved in the project. One of these was involved in writing this proposal.

Student Involvement:

Students will be heavily involved in the implementation of the project on a volunteer basis. Prior to writing the proposal we put out a request on the PoE blog for student help with the project and received an enthusiastic response. Yiyan Ge (in the junior year of the Program on the Environment Environmental Studies program, Department of Economics) has contributed to the writing of the proposal and will also be involved with the project implementation throughout the duration of the project. We have also been contacted by 3 more students who are interested in being involved (Kshitija Madhira, Kiddist W. Emmanuel and Cole Zuckerman).

There are several areas where students will be required. Firstly, there are some technical aspects that need to be worked out or confirmed before the installation can begin. These include: tests to confirm that the emergency lighting of hallways will not be affected as per the building fire code; the determination of the number of sensors to install, and exactly where to install them; and the choice of light monitoring and logging equipment to quantify the impact of the scheme. This will involve liaison with the installers before installation and decision making on these aspects with consideration of the project budget. Further analysis will need to be performed by students post installation too. The main part of this will be retrieving and analyzing the results of the light logger, as well as checking and maintaining their operation. Calculations will need to be performed to quantify the amount of electricity saved by the system in terms of kWh and dollars. The frequency of switching will also be used to calculate the effect on the lifetime of the bulbs, and hence bulb replacement frequency, using published data. From this, an assessment will be done to determine the impact on the cost effectiveness of the project and to quantify whether there is any increase in carbon footprint associated with increased bulb replacement frequency. N.B., preliminary research indicates that any reduced bulb lifetime will be offset by the long periods that the bulbs are switched off for, thus meaning that the actual life of the bulb in real-time will be longer than for continuous operation.

Secondly, the students will be tasked with performing the majority of the outreach and educational aspects of the project. This will include setting up and maintaining the website, Facebook page and Twitter account, making it fun and interesting. They will also be required to make high quality graphs and diagrams of the results of the above analysis and to publish and disseminate them using the different media just mentioned, as well for the various blog posts, newsletters and posters. They will also write and give the seminars describing the results, as well as staffing an information table on Red Square on the Campus Sustainability Day event. Students will also be required to write, distribute and process the surveys to assess the working hours of the building users as well as their opinions both before and after the installation.

Regular meetings between the students and the project leaders (Daniel Grosvenor and Rob Wood) will be held in order to help guide the students and keep them on track, but also to encourage them to come up with their own input and ideas. It is hoped, for example, that the students will come up with further ideas for campus outreach and advertisement of the project. It is also hoped that throughout the project the students will take an increasing amount of control, so that eventually they will be performing the majority of the project management. Thus, we feel that the students will gain invaluable experience in several key areas for career development.

Education & Outreach:

We have several ambitions regarding education and outreach. The project will be readily apparent to the some of the occupants of the building when the light sensors are triggered to switch the lights on or off. However, this may only be true for those people who enter the building first in the mornings, or who work late at night and at weekends when the occupancy is lower. Therefore, there will be the need to inform local users about the project, so that the switching of the lights does not come as a surprise and to allay fears about a lack of lighting. This will happen through emails sent to building occupants, and posters placed on noticeboards in the affected corridors, which will explain the idea behind the project, the likely environmental benefits and, once installed, the electricity savings made (as measured from the monitoring equipment mentioned earlier). We will also send out a survey to building users to both assess the occupancy times, but also to gauge their opinions on the measures and their concerns. This will have the side benefit of providing publicity for the project.

We would also like to publicize the project throughout the campus as a whole with the purpose of getting people to think about whether a project like this could work in their building, or encouraging them to think about other sustainability projects that they could initiate on campus. Through publicity of a successful project we also hope to reach people on campus in influential positions, which will hopefully aid with the roll out of occupancy based lighting throughout campus and possibly beyond. To do this we propose to write articles and newsletters for online and print media that will describe the project before installation and also to present the results after installation. Suggested media include: the UW Today email newsletter; both the College of Environment news blog and the bimonthly newsletter  (The Insider); the Program on the Environment (PoE) posts site/blog, the UW SEED (Students Expressing Environmental Dedication) site; Inter-university sustainability websites/blogs/newsletters; and local press. Other potential media will be researched and identified by students working on the project. They will also be largely responsible for writing the above articles, etc.

The students will also be involved in preparing and updating a project website, Facebook page and Twitter account. As well as general project information, these will provide regular updates on the progress of the project as it goes on. When the installation is complete, and data is being obtained from the lighting sensors, results detailing the amount of power and money saved will be posted every 2 weeks. This will include graphs of the results and interesting comparisons (e.g. “during the last 2 weeks we saved enough electricity to continuously power an electric kettle”). Along similar lines, we will produce monthly posters to present information on the project results for the last month that will be displayed around campus.

We will also encourage campus users to use the Facebook page and Twitter feed to comment upon campus buildings that seem to be bad offenders for wasting lighting energy. These sites will also be a useful way to gauge interest in the project and to gauge the effectiveness of the outreach via the number of comments being posted, number of Facebook “likes”, amount of site traffic, etc. You Tube videos may also be created to advertise the project.

The website will also contain a number of useful educational components, such as details on the cost analysis of the project, e.g. what the payback time of the project is for each floor of the building and how it was calculated; how the materials and labor costs break down; how many sensors and switches were required and where they were placed, etc. The number of times per day that the lights are switched on will also be of interest for the purpose of assessing whether this is having a significant effect on the lifetime of the bulbs. Details on the carbon footprint of any extra bulb replacements could also be provided. This will act as a useful case study for people interested in implementing similar schemes in other buildings. Seminars explaining the project implementation details, problems encountered and the savings results will perform a similar function. Such seminars will also help towards the goal of encouraging others to take up sustainability projects such as this, or other sustainability projects. One platform for the seminars could be the annual Campus Sustainability Day event where an information table on the Red Square would also be set up. The students would also be tasked with identifying other events appropriate for publicizing the project.

Environmental Impact:
  • Energy Use
  • Living Systems and Biodiversity
  • Water
Project Longevity:

Environmental Problem:

The environmental problem is one of electricity wastage and the subsequent environmental damage that results. Washington State generates most of its electricity from hydroelectric power, which affects stream and river flows with impacts on endangered species such as salmon. Additionally, with a growing population, Seattle needs to increase energy efficiency in the future in order to meet future needs using renewables. If future demand cannot be met using renewables then electricity generation from carbon dioxide emitting fuel or nuclear power generation may have to supplement the supply, with resulting impacts on the Earth's climate and on the environment. Our project will reduce the amount of electricity used for UW building lighting by ensuring that corridor lights are switched off when the areas are not in use. The reduction in the amount of electricity that needs to be generated by the utility companies will help improve stream and river flows. Also, reducing electricity usage at the point of use is recognized as one of the most effective ways of scaling back energy generation requirements at the power plant level due to the large loss of energy in transmission.

Explain how the impacts will be measured:

The primary measure of the impacts of the scheme will be the amount of electricity saved in terms of both kWh and dollars. The initial estimates made in this proposal are based upon the prevention of 10 hours per day of lighting made using estimated occupancy times of 6am to 8pm for 365 days a year. It is likely that this is a conservative estimate since large savings are also likely during UW holidays and at weekends. In order to make these pre-installation estimates more robust we intend to take surveys of the building users to assess their working habits.

Once the occupancy sensors have been installed we will set up light monitoring devices that will be enable us to log when  the lights in the corridors have been turned on or off by the occupancy sensors. Since the lights were previously left on continuously this will quantify exactly how much electricity is being saved by the project. Such sensors and loggers are available at low cost and have the advantage of not requiring any devices to be linked to the electrical lighting circuits. The data from this will also be used to assess the frequency of switching, which has implications for the light bulb lifetimes. It is estimated that by requiring 30 minutes of no occupancy before the lights are switched off, the number of times that the lights are switched on can be limited to once or twice per day. Preliminary research suggests that such usage would actually increase the real-time life of the bulbs compared to continuous usage, due to the significant periods of off time during the night, which would not count towards the bulb lifetimes. The data will be able to quantify this and will allow calculations of the overall effect on bulb replacement frequency, the consequent effect on costs, and any changes in the associated carbon footprint.

Total amount requested from the CSF: $7,776
This funding request is a: Grant
If this is a loan, what is the estimated payback period?:


ItemCost per itemQuantityTotal cost
Equipment & Construction
Occupancy sensors94.17181695.06
Wireless switches96.368770.88
Light data sensor and logger109.58876
Publicity & Communications
Large A0 Posters502100
Small posters printing costs0.124024
Personnel & wages
Installation labor (per hour)160264160

Non-CSF Sources:

Project Completion Total: $7,776


TaskStart DateEnd DateTimeframe
Meet with the Department Administrator to discuss the financials and obtain permissions from the Chair1/28/20132/4/20131 week
Produce, distribute and analyze survey to gauge the opinions of building users and their hours of usage of the building1/28/20132/22/20131 month
Inform building users of the project through emails and posters1/28/20133/1/20131 month
Obtain final go ahead from building users and Department Chair1/28/20133/1/20131 month
Confirm that the project will not interfere with the emergency lighting1/28/20132/8/20132 weeks
Finalize the scope of the project, the equipment to be used, positioning of the sensors, and final savings estimates1/28/20133/1/20131 month
Website and Facebook page initated1/28/20133/22/20132 months
Installation and testing of the system3/25/20134/5/20132 weeks
Analysis of preliminary light meter data and presentation onto project website and other media4/29/20135/31/20131 month
Satisfaction survey of building users written, distributed and analyzed4/5/20135/6/20131 month
Spring/summer results from the project presented in fall quarter seminars8/15/201311/29/20133 months
Spring/summer results written up for a news article for UW magazines/blogs8/15/201311/29/20133 months
Continued analysis of fall/winter data9/25/20135/2/20147 months
Full year winter results from the project presented in spring quarter seminars4/21/20145/23/20141 month
Full year results/final report written up for news articles for UW magazines/blogs and project website4/21/20145/23/20141 month

Project Approval Forms: