Enhanced bifacial solar modules for next generation applications 

1. Enhanced
Bifacial
Solar
Modules
for
Next
Genera7on
Applica7ons
Randy
Stewart,
CEO
Prism
Solar
Technologies
bifiPV
Workshop
Konstanz,
Germany
April
22-­‐24,
2012

2. Who
is
Prism
Solar
Technologies?
– Started
in
2005
with
a
mission
to
inves7gate
techniques
in
holography
and
create
new
opportuni7es
in
the
Clean
Energy
marketplace.
• PST
has
designed,
fabricated
and
field
tested
a
series
of
enhanced
PV
modules
where
holograms
aid
in
sunlight
harves7ng.
• PST
has
op7mized
methods
for
high
volume
manufacturing
of
holograms
for
Solar
applica7ons.
• PST
has
introduced
to
the
marketplace,
a
line
of
new
module
products
based
upon
bifacial
solar
cells.
Prism
Solar
Technologies

3. Added
sunlight
captured
by
PV
– Holographic
film
is
spaced
between
rows
of
PV.
– Holographic
film
and
PV
are
laminated
between
two
layers
of
glass.
Prism
Solar
Technologies

4. Sunlight
captured
by
TIR
• Total
Internal
Reflec7on
allows
the
hologram
and
the
two
layers
of
glass
to
act
as
waveguide
for
addi7onal
energy
harves7ng.
• New
design
parameters:
– Width
of
hologram
/
Width
of
PV
is
important
– Angular
efficiency
of
hologram
is
important
– Thickness
of
glass
becomes
important
Prism
Solar
Technologies

5. Prism
Solar
T-­‐120
Product
line
Prism
Solar
Technologies

6. Design
opportuni7es
(or
limita7ons)
• Cell
size
and
number
of
bus
bars
– Width
ra7o
is
important;
we
cut
cells
• Angular
efficiency
of
holograms
– Holograms
op7mized
for
different
moun7ng
structures
• Thickness
of
glass
layers
– Structural
a`ributes
of
glass
are
important
– Thicker
glass
leads
to
greater
contribu7on
from
holograms
• Efficiency
of
Solar
Cells
– Higher
efficiency
=
greater
energy
harves7ng
• Cost
of
Commercial
Solar
Cells
– Compe77ve
marketplace
Prism
Solar
Technologies

7. Solar
Marketplace
Prism
Solar
Technologies
Large
arrays;
poorly
defined
ground
cover.

8. New
Opportuni7es
Prism
Solar
Technologies
Smaller
arrays;
architectural
needs

9. New
Opportuni7es
Prism
Solar
Technologies
Larger
installa7ons;
different
architectural
challenges

10. Demands
of
new
opportuni7es
• Addi7onal
energy
harves7ng
at
non-­‐la7tude
angles
– Hologram
contribu7on
can
be
tailored
to
aid
• Structural
a`ributes
for
building
industry
– Thicker
glass
and
adhesive
interlayer
• Designs
with
useful
features
for
builders
– Posi7on
and
type
of
electrical
connec7ons
– Frameless
modules
are
more
important
• Enhanced
reflec7vity
of
neighboring
surfaces
– Improving
bifacial
value
posi7on
– Example
is
the
Commercial
White
Roof
opportunity
Prism
Solar
Technologies

11. Holograms
for
enhanced
efficiency
0.0
2.5
5.0
7.5
10.0
12.5
15.0
17.5
20.0
22.5
25.0
27.5
30.0
-­‐30
-­‐25
-­‐20
-­‐15
-­‐10
-­‐5
0
5
10
15
20
25
30
35
40
45
50
55
60
Contribu)on
to
the
cell
(%)
Declina)on
angle
(theta)
Ver7cal
Hologram
La7tude
Hologram
Prism
Solar
Technologies

12. Build
&
Test
Full
Size
Modules
Prism
Solar
Technologies

13. Primary
moun7ng
axis
0
25
50
75
100
125
150
175
200
0
15
30
45
60
75
90
Power
(Wa8s)
declina)on
(degrees)
Pmax
(Low
Tilt
Hologram)
Pmax
(Spaced
Bifacial)
Pmax
(La7tude
Hologram)
Prism
Solar
Technologies

14. La7tude
Hologram
Prism
Solar
Technologies
Spaced
Bifacial
Reference
Module
La7tude
Hologram
Module

15. Hologram
for
Ver7cal
Moun7ng
Prism
Solar
Technologies
Spaced
Bifacial
Reference
Module
Ver7cal
Hologram
Module

16. Difference
Prism
Solar
Technologies

17. Yearly
Performance
of
the
Hologram
for
a
module
mounted
ver7cally
Hologram
Designed
for
Ver7cal
Moun7ng
Prism
Solar
Technologies
Hologram
Designed
for
La7tude
Moun7ng

18. Yearly
Performance
of
the
Hologram
for
a
module
mounted
ver7cally
Prism
Solar
Technologies
Hologram
Designed
for
La7tude
Moun7ng
Hologram
Designed
for
Ver7cal
Moun7ng

19. Hologram
Efficiency
v
La7tude
Prism
Solar
Technologies

20. • New
opportuni7es
for
bifacial
solar
cells
– Improved
performance;
both
front
&
back
• Solar
module
installa7ons
are
changing
– Addi7onal
energy
harves7ng
can
be
put
to
work
• New
design
parameters
to
achieve
best
performance
– Structural
glass,
frameless
modules
and
unique
architectural
features
• Cost
will
always
remain
important
Prism
Solar
Technologies

21. Thank
You
Prism
Solar
Technologies
www.prismsolar.com

22. Prism
Solar
Technologies