The High Cost of Low Energy

How we choose between reducing costs or reducing energy consumption when we could be doing both

by: Zach Dvorak
Freshman, Economics
Mooresville, NC
zdvorak@unc.edu

In 1999, the University of North Carolina kicked off an ongoing campaign to be more environmentally conscious and to institute sustainable practices across campus.  Four years later, students got involved when the Renewable Energy Special Projects Committee (RESPC) was formed as a liaison between the Sustainability Office and the Carolina student body.   Ever since, this group has helped determine which sustainability projects the university should pursue by contributing approximately $200,000 per year in funding – collected in the form of a student fee of $4 per student, per semester.   While the RESPC has been able to implement a plethora of energy efficient projects with fees it has collected over the past several years, it does not always do so with a large degree of financial responsibility.

According to the UNC Sustainability Office’s most recent report, the RESPC has funded 24 campus projects intended to decrease overall energy use, switch to more efficient sources of energy, and raise environmental awareness at a total cost of $1,275,105 to students.  The least expensive of these projects was an $800 initiative to encourage students in labs to keep fume hoods closed as much as possible.  At the other end of the financial spectrum, the RESPC allocated $210,000 to the installation of 34 geothermal wells at the North Carolina Botanical Garden. These wells were created to circulate water, having it cool in the summer, and warming it up in the winter in a more efficient way.

While the RESPC chooses to invest in a wide variety of projects, over 40% of its total investments have been in the field of solar energy.  The committee has funded a system of photovoltaic cells on top of the Bell Tower Parking Deck, and it has spent hundreds of thousands of dollars on research exploring the feasibility of installing solar systems on the roof of Fetzer Gym as well as the Cobb Parking Deck.  Most notably, however, is the committee’s effort to fund an array of solar panels that line the roof of Morrison Residence Hall.

Part of a 2006 renovation project, the 172 solar panels on top of the south campus high-rise collect energy from the Sun that is used for hot water heating.  Student fees covered $184,000 (which amounted to less than half) of the cost of this project.  After five years in operation, it seems that this money may have been better spent elsewhere.

Financially speaking, the Morrison solar hot water system could theoretically save the university a maximum of $11,275 per year.  Even at full efficiency, the payback of this project is likely to be decades.  But the RESPC is aware of this – UNC’s Sustainability Office is quick to admit that environmentalism comes at a cost.  Looking back at the Morrison renovation project, has the cost to be environmentally conscious been justifiable?

According to the Sustainability Office, the system can generate 6,000 gallons of hot water on a clear, sunny day.  Our region sees an average of 111 of these clear, sunny days per year, but many of these occur during the summer months when dorms are largely unoccupied and hot water demand is low.  On overcast days, the system is extremely inefficient, and Morrison’s steam-powered air heating system kicks in to meet hot water demand.  Days like this render the solar panels on the roof superfluous.

A further burden of the solar system is the fact that it must be maintained and repaired as panels fail to operate as expected.  Additionally, a university case study on the project reports other problems, including an orientation defect that caused half of the panels along Morrison’s X-shaped roof to counterproductively radiate collected energy back into the atmosphere.

Ignoring its pitfalls, this system is capable of providing the university about 96,000 kilowatt-hours per year of environmentally friendly electricity.  However, Morrison residents consume nearly 4 times this amount of electricity in a given year, and when energy consumption is highest in the winter, overcast days render the solar panels minimally effective.

A subtle benefit of this project is the publicity that it generates, as simply having solar panels on campus draws attention to the university as an environmentally friendly institution.  But ultimately, the solar panels on Morrison’s roof are both expensive and less effective than would be desirable.  Fortunately, there are better ways for the RESPC to invest its money with measurably greater results.

In March 2010, the RESPC demonstrated the way students’ money should be spent on sustainability projects.  Motivated by the EPA’s National Building Competition, the RESPC allocated $35,000 to the reduction of energy consumption in a building on campus.  In an effort to continue the sustainability efforts mentioned above, Morrison Residence Hall was chosen for the contest.   With such a small budget, the project required the use of resources that were inexpensive or already available.  After examining different options, the committee decided to optimize existing HVAC systems, upgrade the lighting in much of the building, and educate the residents on how to be more energy conscious.

Collectively, these efforts led to a 35.7% reduction in energy consumption.  The EPA reported that the residence hall’s upgrades will save the university over $250,000 per year in energy bills and help prevent over 730 metric tons of greenhouse gases from being released into the atmosphere.

The lighting upgrades in Morrison entailed replacing 242 light bulbs with more efficient LED or simply light bulbs with a lower wattage.  The cost of these bulbs was $8,970.  The yearly savings from this switch has been about $4,282, meaning the new light bulbs paid for themselves in just over two years.

More impressive, though, is the fact that over 94% of the energy reduction in Morrison Residence Hall resulted from reprogramming the HVAC system. This initiative simply took something that was operable and made it work better.  The heating and air-conditioning system was not replaced or upgraded to a more energy-efficient model.  Instead, it was inspected to ensure proper operation and then programmed to operate under specific guidelines that ensure maximum efficiency without sacrificing resident comfort.  As a result, energy consumption in Morrison Hall was reduced by 33.7% at very little cost to the university or its students.

While saving energy can come at a high cost, it would certainly make more sense for the RESPC to invest in initiatives that aim to reduce energy consumption in a financially responsible manner.  This means pursuing projects such as lighting upgrades and HVAC optimization where a $35,000 investment can result in quarter-million dollar savings while abandoning flashy, but inefficient projects such as quarter-million dollar solar systems that often fail to meet energy demands and result in trivial $10,000 savings.

http://respc.web.unc.edu/files/2012/12/respcbanner3.png

This article’s picture can be found at: http://respc.web.unc.edu/.

 

 

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