A new step toward environmentally friendly
electricity has been made through the discovery of a new alloy material that
converts heat into electricity directly.
Richard James, study leader and University of
Minnesota aerospace engineering and mechanics professor, along with University
of Minnesota aerospace engineering and mechanics post-doctoral researchers
Vijay Srivastava, Kanwal Bhatti and Ph.D. student Yintao Song, have used a new
alloy to create
electricity from heat. This could eventually lead to capturing waste heat
from car exhaust and using it to create electricity for a hybrid car battery,
thus recycling energy.
The material was created through the combination
of elements at the atomic level. This led to the development of a new
multiferroic alloy called Ni45Co5Mn40Sn10.
This alloy underwent a "highly reversible" phase transformation where
a solid turns into another solid, and during this transformation, its magnetic
properties changed. These changes show in the energy conversion instrument. The
material starts out as non-magnetic, and then becomes increasingly magnetic as
the temperature increases. The material absorbs the heat and produces
electricity in a coil.
Some of the recovered
heat is lost through the process hysteresis, but the
University of Minnesota team found a way to reduce this process and absorb more
"This research is very promising because it
presents an entirely new
method for energy conversion that's never been done before," said James.
"It's also the ultimate 'green' way to create electricity because it uses
waste heat to create electricity with no carbon dioxide."
The team is also working on making a thin film of
the material to convert heat from computers into electricity.
"This research crosses all boundaries of
science and engineering," said James. "It includes engineering,
physics, materials, chemistry, mathematics and more. It has required all of us
within the university's College of Science and Engineering to work together to
think in new ways."
study was published in Advanced
quote: This gives a rather low efficiency of 0.004% . In our present designs a lot of the latent heat is not being used to make electricity.