Return to C&J Online News home page

Solar power shines again at UNM

--Photo by RANDY MONTOYA

UNM students Gehan Kaviratne (left) and Eric Ulrich install the new solar thermal collectors on the roof of UNM's Mechanical Engineering Building.

In a world of ever-increasing energy costs, inflation concerns, and political unrest, it is becoming harder and harder to miss the headlines about diminishing energy resources, or to ignore that steadily increasing figure on your utility bills.

The University of New Mexico is no exception to these economic challenges. However, for the university the solution to reducing those energy costs was hanging overhead all along.

The roof of UNM's Mechanical Engineering Building has been home to a system of energy-saving solar panels for the past 26 years. For most of that time, the system had been all but forgotten. Until, that is, UNM Associate Professor of Engineering and renewable energy researcher Andrea Mammoli stumbled upon the system and saw a golden opportunity to resuscitate the dilapidated solar panels.

"There was a whole system of water storage tanks, pumps, and solar panels that had essentially been forgotten about up here," says Mammoli standing among the panels four stories above the university campus. "The potential waiting to be realized was incredible."

When the Mechanical Engineering Building was completed in 1980, it was designed to be a model of energy efficiency during a time of rising energy costs and diminishing reserves. A system of thick walls, small windows, and solar panels all worked to make the building the most energy efficient on campus.

However, as the costs of traditional energy sources receded in the late '80s, funding for system maintenance was cut. When ethylene glycol from the panels began to damage the roof shortly thereafter, the system was abandoned all together.

--Photo by RANDY MONTOYA

UNM professors Andrea Mammoli (left) and Peter Vorobieff examine solar thermal collectors on the roof of the Mechanical Engineering Building on the UNM campus. Sandia is helping upgrade the solar system to the latest technologies.

Solar power rides again

Thanks to the work of David Menicucci, Sandia research engineer and manager of the energy surety program, with professors Mammoli and Peter Vorobieff, a project is underway to bring solar power back to the Mechanical Engineering Building.

Mammoli discovered the Clean Energy Grant Program by New Mexico Energy, Minerals, and Natural Resources Department, which offered a funding for clean energy systems. Mammoli approached David with his idea for rebuilding the solar panels, and together they wrote and submitted a proposal to refurbish the system.

When the review board's results were announced, Mammoli and David's proposal was the highest-ranked proposal submitted, and the team was awarded the nearly $200,000 grant.

The grant's funds will allow the team to replace the system's old, smaller panels with new, more efficient panels.

"The new collectors we bought are much bigger than the old collectors, so the total surface area of the 40 new collectors is approximately equal to that of the 88 old collectors," says Mammoli. "These new collectors reflect 25 years of technology improvement and are much better performers -- especially in high-temperature applications such as this one."

A portion of the funds will also provide for renewable energy research and the salaries of students who assist with the refurbishment project.

New and improved

Although many of the systems that debuted in the 1970s, such as the one on UNM's engineering building, were carefully designed and put together, they often did not work properly. Consequently, solar power systems developed a bad reputation in the '70s and '80s, says Mammoli.

"Our system was not poorly designed; however it was a complex system and thus was prone to failures without careful and continued maintenance," he says. "Also, the old control systems were not as reliable as the modern microprocessor based ones, which we now have."

In order to avoid the fate of the original system, the refurbished system will make use of multiple redundancies and fail-safes.

"We'll have multiple pumps on uninterruptible power, a valve system to protect the panels from damage, and we'll now be using pure water in the system, rather than the ethylene glycol originally used," says Vorobieff.

Originally, the system only provided heating for the 70,000-square-foot building. With the help of Vorobieff, Mammoli redesigned the system to include an absorption chiller, making the new system capable of providing both air conditioning and heating.

By Mammoli's conservative estimates, the new and improved system will prevent 100 tons of carbon dioxide emissions a year and a 20 percent reduction in utility costs.

Of course, the only drawback of a solar energy system is that the sun isn't in the sky 24 hours a day.

"An inherent problem with the supply of energy is that it is in highest demand when it is least available," says Vorobieff.

With some innovation, Mammoli and his team have overcome this limitation.

  "By employing thermal storage tanks, that renewable energy source is now available to us at anytime," says Mammoli. "A unique benefit of New Mexico is that weather conditions are fairly easy to predict, which makes it easy to manage the loads on the energy supply."

Looking to the future

The research and development goals for the renovated system will benefit both Sandia and the university, says David. "The grant we've received will allow us to establish a 'test bed' where we will be able to perform research on the solar energy systems. This is particularly exciting because here at Sandia, we have no solar collectors quite like what they have at UNM."

In fact, it is the educational possibilities that most excite David about this project.

"We're going to be studying the configuration and components of these systems, and exploring ways to increase their performance and efficiency as well as operations strategies for the economic aspects of these systems," says David. "The opportunities that will be created through this project for students to perform research, publish joint papers, and gain real hands-on knowledge and experience in this area of technology are just fantastic."

Students and faculty alike are already involved with the project. Professors Mammoli and Vorobieff are working to create a curriculum on the practical application of sustainable energy systems with focused studies in solar energy and energy management, thereby putting UNM "on the map" in the renewable energy community, says Mammoli, who already is teaching a course in sustainable energy.

Mammoli also hopes to expand the system to the adjacent Nuclear Engineering Building in the near future for a nighttime radiant cooling system, which would release heat into the night sky as a means of cooling.

The team is collaborating with local company Energy Control Inc. on the GridWise program, a DOE initiative aimed at making the electricity grid more efficient, robust, and flexible.

"Bud Wildin, ME Professor Emeritus and original codesigner of the system, deserves a lot of credit for the first design and for all the advice he is providing for the refurbishment," says Mammoli.

"We also really have a lot to thank David Menicucci for with his contributions on this project," says Vorobieff. "David's an inspiration for us."

Go to Top