Is solar t h e a n s w e r?
Dr Franky So, chief technology o cer of Nextgen
Nano, debates the ecological and economical energy
benefi ts of photovoltaic solar panels, and why a
new breakthrough is looking bright for EV applications
Research has revealed that electricity produced from
solar cells reduces air pollutants and greenhouse
gases by about 90%, compared with conventional
fossil fuel technologies.
However, despite seeming like the perfect renewable
energy solution, arguments persist against photovoltaic
panels (PVs). These include that it’s more expensive to
produce power from solar energy than traditional fossil
fuels, such as coal and natural gas. Another argument is
that solar thermal energy systems are more expensive per
unit of energy generated; although a counter argument
would be that solar energy is cheaper over time because
it lacks feedstocks.
There are several diff erent types of photovoltaics.
About 90% worldwide are based on some variation of
silicon, which takes many forms depending on the
element’s purity. This purity depends on how perfectly
aligned the silicon molecules are and determines how
well the cell is at converting solar energy, known as the
photoelectric eff ect.
Solar cells made of monocrystalline silicon (mono-Si)
contain cylindrical silicon ingots. They have the highest
e ciency rates, typically 15 to 20%, because they are
made of the highest-grade silicon. Yet, they are also the
most expensive and the circuit will break down if it is
even partly covered by dirt or shade.
Polysilicon (p-Si), or polycrystalline silicon, cells are
cheaper to produce than their mono-Si relatives, with
a slightly lower heat tolerance. However, their
disadvantages include an e ciency of just 13 to 16%,
as well as lower space e ciency.
Generally, the solar industry highlights the low costs of
p-Si and also the technical components of solar cells, yet
these components represent less than half the cost of an
202 // January 2020 // www.electrichybridvehicletechnology.com
The evolution of
materials for effi cient
and fl exible solar
technology will take
the burden off the grid
installed solar system. Larger costs arise from
installation, maintenance, insurance and operation.
Thin solar panels, many of which are in the early
research and testing stages, have showed the most
potential for e ciency. This especially applies to Copper
Indium Gallium Selenide (CIS/CIGS) solar cells. However,
newer thin fi lm technologies degrade quicker than older
models, off setting much of the presumed benefi t.
Some argue that the only way to economize power
consumption is not with the use of PVs, but simply by
using less power overall. But, an evolution in PV
technology that uses lightweight organic polymers in
place of silicon could hold the answer to issues of
e ciency, economy, and burden on electrical grids.
By combining organic semiconductors and PVs, the
result is cells that have the potential to be more e cient,
and can be used to make fl exible and semi-transparent
solar panels. Given the high e ciency of polymer solar
cells, it’s expected that the e ciency of transparent solar
cells can reach beyond 13%.
What makes the system diff erent is the use of
nanotechnology. In the case of PVs, it’s likely that
nanotechnology will make solar power more economical
by reducing the cost of constructing solar panels and
Possible applications of this technology have the
potential to transform and decentralize energy usage
for EVs. Rather than simply plugging EVs into charging
points connected to the grid, there’s potential to charge
the vehicle through panels contained within the car
itself. This could alleviate the burden on electrical grids
where at least 89% of air emissions associated with
electricity generation could be prevented if electricity
from PVs displaces electricity from the grid.