Questions and answers with Michael E. Mackay

The “ultimate energy source for humankind” is how author Michael Mackay, in the preface to his text, Solar Energy: An Introduction (Oxford University Press, 2015), reminds his readers of the Sun’s importance. The text “introduces students to a wide range of applied physics and engineering topics, including thermodynamics, solid-state physics, light absorption and emission, PV devices, solar chimneys, solar towers, and solar thermal flat-plate collectors,” writes National Renewable Energy Laboratory’s Nancy Haegel in her book review for this month’s Physics Today. In a world in which both carbon emissions and PV installations are increasing, she adds, Solar Energy is “a timely contribution.”

A distinguished professor of materials science and engineering at the University of Delaware, Mackay has research interests in solar cells, nanotechnology, and rheology. He specializes in understanding how nanoparticles improve polymer performance. One recent focus of his work has been developing polymer-based solar cells that can be applied to various surfaces.

Mackay received his bachelor’s degree in chemical engineering from Delaware and his master’s and PhD degrees from the University of Illinois at Urbana-Champaign. His career also includes a stint at Procter & Gamble, the global consumer-products manufacturer.

Physics Today recently caught up with Mackay to discuss his first book.

PT: What inspired you to write this book?

MACKAY: I have a deep commitment to the utilization of renewable energy sources, and I wanted to provide the next generation of engineers and scientists with a textbook that might aid them in fully realizing the power of solar energy.

PT: How challenging was it to write a text on such a dynamic field?

MACKAY: That was indeed a challenge. However, I concentrated on the fundamentals of solar-energy utilization, which allowed the textbook to be useful even as researchers explore the field in ways not yet anticipated.

PT: In what ways does your book prepare students and professionals to address current and future challenges in solar energy R&D?

MACKAY: I believe the information in a textbook should be generalizable, to give engineers and scientists the ability to use the information to design new technologies. I hope that is what the reader can accomplish after reading the textbook. That is very different to writing a compendium of information that is useful only for the technologies at hand.

PT: What fundamental R&D and sociopolitical breakthroughs do you think are needed to achieve 1-TW global PV installation, an aspiration of some in the solar energy R&D community?

MACKAY: I believe, by its very nature, solar energy is a distributed power source and should be treated as such. So to achieve large PV installation, the focus should be on providing solar power to houses or communities rather than to the grid. That will require the power system to provide DC rather than AC current to energize computers, multimedia devices, appliances, and the like. And that will eliminate costly inverters that demand maintenance. Most RVs use DC power for some of their appliances, so why can’t people in houses do so, too? It makes no sense to take AC power and then convert it to DC just for computers and other similar devices.

PT: What books are you currently reading?

MACKAY: I am reading books on 3D printing. My training as a PhD student was in the area of polymer processing and rheology, and I recently decided, when asked by the chair of the materials science and engineering department, to teach a course next semester on [those topics]. I want the course to include a discussion of modern polymer-processing equipment, like that used in 3D printing, and I am ascertaining if anything has been written specifically about this before. I am in the middle stages of developing the course and hope to have it worked out in a couple of months.