Transcript Powerpoint Template - Boulder Valley School District

Applications of
Electrochromic Materials in
Greenhouses
By: Divya Arcot
Monarch High School
Background

Electrochromic devices are composed
of metal oxide substances which vary
optical and thermal properties in
response to changes in voltage.
(change opacity and emissivity)

Optical properties are reversible,
meaning the original state of the device
can be restored by changing the
polarity of the voltage.

These characteristics grant useroperated dynamic control over:


Amount of light allowed to pass through
Amount of heat allowed to pass through
Basic Structure of an Electrochromic device,
depicting transport of ions under an electric
field [Granqvist].
Current Applications
 Energy efficient “smart windows”
 Informational displays
 Variable-reflectance mirrors
 Variable-emittance surfaces
Research Goals
 As the market for Electrochromic materials is on the rise,
research is being conducted to discover other areas in
which these materials are applicable.
 The goal of this research :
 To determine whether the controlled variability of opacity
offered by Electrochromic materials would increase the
effectiveness of Greenhouses.
Future Applications
 Energy efficient greenhouses
for impoverished villages
located in areas with harsh
climates
 Urban gardens
 Future spaceflight , when
astronauts must grow food on
the spacecraft, simulating
Earth-like conditions on
lengthy missions (to Mars and
beyond)
Hypothesis
If light is key to photosynthesis, and the
amount of light which a plant receive is
varied by the opacity of the Electrochromic
material shielding it from the light source,
photosynthesis, and hence the growth rate
of the plant will be impacted.
Methods
Controls
 A layer of transparent glass
will be placed between the
plants and the light source.
Test Plants
 Electrochromic material
with varying opacity will be
placed between the plants
and the light source.
A Thermal Radiation Sensor and PASCO’s calibration curve will be used to
determine the amount of light received by the plants.
 To determine the impact of the varying transparency on the plants:
• Vertical plant growth will be measured
•Amount of leaves will be recorded
•Plant progression through stages of development will be monitored
If the plants are not responding well, variable opacities will be changed and
retested.
Methods
Control
Test 1
Test 2
Test 3
ECD
ECD
ECD
Greenhouse Experiment Setup
Methods
 Unfortunately, I was not able to acquire the Electrochromic Devices (ECD)
 As a result, I changed my experiment in the following manner:
 Control = Simulation of outdoor conditions

Test 1 = Simulation of clear ECD state (Plexiglas frame)
 Test 2 = Simulation of darkened ECD state (Plexiglas frame covered w/ window tint)
Control
Test 1
Alternate Experiment Setup
Test 2
Methods
 All Arabidopsis thaliana Wild-type plants
received:
 16 hours of light under the constant light source
of fluorescent bulbs.
 8 hours of dark
 All were grown in agarose gel
Data
 All data collected for the Arabidopsis thaliana
Wild-type plant was rendered unusable due
to a severe mold infestation of all plants
White
Mold
Data
 However, an interesting pattern was forming:
Arabidopsis were dying and mold infestation was occurring more
rapidly in the control plants than the test plants
Control - Arabidopsis
Test Chamber 2 - Arabidopsis
Methods
 I then began collecting data
on Matrix Morpheus
flowers
 The following
characteristics have been
observed:


Matrix Morpheus

(Pansy)


Stem length
Amount of leaves
Leaf color and general appearance
Amount of blossoms
Blossom color and general appearance
Data
 From observations of the Matrix Morpheus plant, I
have determined that:
 Plants in Test Chamber 2 are developing lighter green spots
on their leaves, but plants overall are healthier than those in
Test Chamber 1 or the Control Chamber:
Light green patch
developing on a Test
Chamber 2 Plant
Test Chamber 2 Plant –
full color transformation
Data
 Plants in Test Chamber 1 are green, but dehydrated.
Test Chamber 2 - Plants
Test Chamber 1 - Plants
 Plants in the control chamber are drier than plants in
both test chambers:
Control - Plants
Data
 Additionally, I continued to observe the mold
from the Arabidopsis plants.
 After the Arabidopsis died, the mold began to
follow the same pattern of death:
Control - Mold
Test Chamber 2 - Mold
Analysis
 The increased survival rate of the Arabidopsis in Test
Chamber 2 (w/ window tint) vs. the Control
demonstrated that additional protection did contribute
to the plants immunity to mold infestation.
 The fact that the mold followed the same pattern of
death shows that when the light sources acts as a
stressor, it is beneficial to have some form of protection.
 However, Chlorophyll production was impacted in Test
Chamber 2 (w/ window tint) because the constant shade
proved to be too dark, and hence photosynthesis was
also affected.
Conclusions
 The Arabidopsis thaliana, Mold, and Matrix
Morpheus plants have demonstrated that
protection from an intense light source is
helpful to plants. The Matrix Morpheus
experimentation has also shown that too
much protection can also cause harm.
 Therefore, the controlled variability of
opacity offered by Electrochromic materials
should increase the effectiveness of
Greenhouses by providing different levels
of protection.
 However, this needs to be tested by further
research.
Further Research
 Biometrics/ LabVIEW – Programming to manipulate
greenhouse environment in order to maintain suitable
living conditions for the plants
 Potential hindrances:
 Size specifications – still in development
 Cost
 Variability, created by the fact that each ECD manufacturing
company has its own unique patent on the device
Bibliography

Granqvist, C. G., “Electrochromic tungsten oxide films: Review of
progress 1993-1998”, Solar Energy Materials & Solar Cells, Vol. 60, 2000.

Granqvist, C. G., “Handbook of Inorganic Electrochromic Materials”,
Elsevier, 1995.

Mortimer, Roger J., “Electrochromic Materials”, Chemical Society
Reviews, Vol. 26, 1997.

Human Spaceflight Mission Analysis and Design. New York: McGraw-Hill,
2000. Print.

"How Smart Windows Work"" HowStuffWorks "Home and Garden" Web.
17 Oct. 2009. <http://home.howstuffworks.com/homeimprovement/energy-efficiency/smart-window.htm>.
Acknowledgements
Thanks to Jonathan Metts for his guidance and
Mrs. Kristin Donley for her resources and
instruction!