Like many engineers, Marcelo R. Fernandes, a third-year doctoral student in mechanical engineering (MECH), is an idealist with a practical bent. He sees a problem – in his case, the pressing need for renewable energy – and goes about solving it systematically.
“Marcelo came into the program after doing undergraduate research in solar energy, and it’s now his passion in graduate school,” said his adviser, Dr. Laura Schaefer, the MECH department chair and Burton J. and Ann M. McMurtry Chair in Engineering. “His project should be useful for increasing solar-cell efficiency, and for boosting the amount of waste heat that we can harvest at the same time.”
Fernandes was born and raised in Belo Horizonte, the sixth-largest city in Brazil. His parents, now retired, previously worked as a mechanical engineer managing a construction company and as a kindergarten teacher.
“I have always liked math and physics, but it was not until college that I became excited about solving engineering problems that have an impact on people’s lives. This has been my focus since starting graduate school,” Fernandes said.
In 2016, he earned a B.S. in MECH from Pontifical Catholic University of Minas Gerais in his hometown. Earlier this year, he earned his M.S. in MECH at Rice, with a thesis titled “Long-term analysis of small-scale concentrated photovoltaic-thermal (CPV-T) system with a nanoparticle-based optical filter.”
Fernandes models the application of nanotechnology to solar-power generation. Most solar panels in use today are made of silicon. They work well but a significant portion of the energy is converted into heat, especially when light concentrators are used. For this reason, researchers have begun exploring the use of selective filters consisting of nanoparticles in fluids, which can transmit the useful energy to the solar cells while also absorbing energy in the form of heat before it reaches the cells.
Fernandes proposes that a concentrated photovoltaic-thermal system using nano-fluid optical filters can both generate electricity and absorb heat from sunlight. The simulations he has created suggest that his proposed CPV-T system can offset roughly 1.317 tons of carbon dioxide (CO2) per year per household.
If the system were implemented in just 10 percent of the households in the United States, the total CO2 offset would be equivalent to the greenhouse gas emissions from 3.19 million passenger vehicles per year.
“The work we are doing is not far away from the lives of regular people. With technology we can help the environment and have a real impact,” Fernandes said.