Cooperative Living February 2021 - 26

CloserLook | by Maria Kanevsky, Contributing Columnist
A Bright Outlook
for Solar Tech
This is not your grandfather's solar power,
or even your father's
S
olar energy is one of the fastest-growing forms of
energy in the country. You can see it on neighbors'
rooftops or in acres of fields, but how did solar energy
begin? And where is the technology headed?
When semiconductors are exposed to light, they can emit
electrons to create an electric current. The first solar cells
used selenium to create the " photovoltaic effect, " which is
the generation of electricity from light exposure. Today, we
use silicon.
Although solar photovoltaic technology was developed
in the 1800s, it took more than a century for the technology
to become more commonplace. The space age in the 1950s
and 1960s saw a slight increase in production of solar
photovoltaics to power spacecrafts. An oil shortage in the
1970s brought more awareness to alternative energies.
BETTER RESULTS
During the last century, the efficiency of solar cells' ability
to generate electricity improved from about 4% in the late
1800s to approximately 11% in the 1950s. Now, modern solar
cells have an efficiency of around 15% to 20%.
With solar energy becoming more mainstream, other
emerging technologies could play a role in coming decades.
Concentrating solar power technology uses thousands
of mirrors to concentrate solar energy to traditional steam
turbines or engines to generate electricity. This type of
technology needs to be located on about 500 acres of land
to be cost-effective.
Another existing type of solar technology is solar heating
and cooling, which collects thermal energy to be used directly
for water heating, space heating and space cooling across
many applications.
A completed floating solar PV array on
a water retention pond in Walden, Colo.
Solar photovoltaic technology was first developed
in the 1800s, but it took more than a century for
the technology to become more commonplace.
LOUNGING IN THE WATER
Several forms of experimental solar technology are
relatively less developed, such as floating solar arrays, also
called floating photovoltaic.
This technology uses solar panels fixed on top of a
buoyant structure in a body of water. Most FPV arrays are
located on inland bodies of water because the calmer waters
allow for easier installation and less degradation of the
technology over time.
The water also helps to cool the solar panel, which
increases the efficiency of electricity generation. While not
all environmental effects are known, in certain habitats FPV
can provide shade to reduce evaporation and the growth of
algae blooms. A huge benefit of FPV is freeing up valuable
land for other uses and reducing the need to remove forests
for large solar arrays.
Another relatively new form of solar technology is
printable solar cells -- photovoltaic cells that are paper-thin
and can be used almost anywhere.
Instead of silicon that is used in conventional photovoltaic
cells, these cells break down organic semiconductor polymers
into " solar ink " on a plastic film, which can then generate
electricity from light.
Although the technology has been proven to work,
printable solar cells last only six months and only have
an efficiency of 10%. Researchers are working to solve
these challenges so printable cells can be placed on the
sides of buildings, not just rooftops, and a variety of
other applications.
As newer forms of solar technology develop and become
commercially available, we will likely see many more kinds
of solar technology around us. Solar technology has come
a long way over the last century and won't be slowing down
anytime soon. ■
Maria Kanevsky is a program analyst for the National Rural Electric
Cooperative Association.
24 | Cooperative Living | February 2021
co-opliving.com
PHOTO BY DENNIS SCHROEDER, NREL
PHOTO BY DENNIS GAINER, NRECA
PHOTO BY DENNIS GAINER, NRECA
http://www.co-opliving.com
Cooperative Living February 2021

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