4 gerritsen-cea ines-ok
TRANSCRIPT
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
VERTICAL POTENTIAL OF BIFACIAL MODULES
1
2nd workshop on BIFACIAL-PV 26/27 May 2014, Chambéry, France
Ya Brigitte ASSOA - Building energy lab (LCEB)Bruno SORIA - PV-modules lab (LMPV)Masakazu ITO - PV-systems lab (LSPV)Eric GERRITSEN - PV-modules lab (LMPV)
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
2
Vertical potential of bifacial modules
3 case studies :
Double-skin facade integrationBI2PV: bifacial building integrated-PV
Vertical facade demonstratormethodology to evaluate the annual potential of innovativebifacial module architectures optical / electrical characterization & simulation
Vertical ground-mounted bifacial systemsglobal simulation of annual yield using direct and diffuse radiation plus land reflected albedo
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
3
3 case studies :
Double-skin facade integration - Brigitte Assoa
Vertical facade demonstrator
Vertical ground-mounted bifacial systems
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
4
ventilation IAQ/IEQair tightness
glazed surfaces Coupling of PV, thermal & visual comfort. Passive heat gain
structuresthermal inertia
BIPV systemsfacades & roofs
insulation layersThermal exchangeWater transferLife cycle analysis (LCA )
INES - Building Energy Lab
rolling shutterscontrol strategy
solar thermal systemsHot water systems (CESI/ CESCAI) Solar combined systems (SSC) Interseasonal thermal storageSolar cooling
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
5
integration of bifacial PV-modulesinto a double-skin facade
Objectives : • impact of configuration parameters on thermal and electrical performance.
• impact of solar heated air in the double-skin on building heating demand
Parameters :• distance between front- and backside of double-skin facade (10 to 80 cm)
• reflectivity (color/roughness) of the inner surfaces
south-oriented double-skin facade of a PASSYS unit with
two bifacial PV modules
reflective surfaces insidedouble-skin facade
test unit / reference unit (reflective coating / plywood)
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
6
Effect of coating reflectivity on relative electrical ga in (in Wh, relative to plywood reference) :
white 1: R = 85-90% � gain = 8%white 2: R = 70-80% � gain = 6%white 3: R = 50-80% � gain = 3%reference (plywood): R = 20-80% � gain = 0black: R = 5% � loss = -9%
� gain (bifacial – monofacial ) = 17%
Effect of distance between inner and outer wallon relative electrical gain (compared to plywood reference)
� gain increases with distance …..
spectral reflectivity
white 1
white 2
white 3
white 1
white 2
white 3
The choice of reflector material and double-skin thickness dependson customer requirements for either electrical (� white coating / large gap)
or thermal (� dark coating / narrow gap) energy mix optimisation
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
7
3 case studies :
Double-skin facade integration
Vertical facade demonstrator – Bruno Soria
Vertical ground-mounted bifacial systems
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
8
INDOOR CARACTERIZATION
OUTDOOR VALIDATION
RAY-TRACING SIMULATION: TracePro®
double mirror setup in PASAN solar simulator
vertical façade test bench& additional configurations
‘ the sky is the limit ’diffuse/direct
reduced scale vertical façade application with 2x2 cell modules
BIF vertical east-west
monofaciallatitudeangle
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
9
1st step: INDOOR CARACTERIZATION � IV parameters for various architectures
resistive losses withincreasing irradiance
upto 2 suns� use half-cells
standard half-cells
gain of half-cells vs. standard : linear gain with irradiation due to lower resistive losses
textured glass
Isc gain with texturedglass vs. flat glass: angular response for 2 orientations
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
10
2nd step: RAY-TRACING SIMULATION
15-22 % bifacial gainfor optimized distance
standard architecture
linear power gain fromindoor characterization
(‘quantity’)+
irradiance non-uniformityon front and backside
(‘quality’)
half-cell architecture
non-uniform distribution on back � beneficial impact of half-cellarchitecture ?
angular response fromindoor characterization
+angular distribution
on front and backside
textured glass architecture
example : 20/02/13 at 12h
FRONT BACK
angular distribution of diffuseirradiance � beneficial
impact of textured glass ?
BACKFRONT
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
11
3rd step: OUTDOOR VALIDATION � on several configurations and different seasons
model validated by outdoor measurements
standard architecture
gain (half/std) with increasingirradiance. Additional gain for
non-uniform irradiance
half-cells
large gain for direct flux in morning & evening.
Low gain for diffuse flux throughout the day
� overall gain: 4-6%
textured glass
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
12
3 case studies :
Double-skin facade integration - Brigitte Assoa
Vertical facade demonstrator
Vertical ground mounted bifacial systems - Masakazu Itovisiting scientist Tokyo Institute of Technology
now at Waseda University (Japan)
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
13
Irradiation data: NASA/SSE
Albedo data: ISLSCP II MODIS (collection 4)Example on next slide
GREEN: vertical bifacial oriented East/West performs at least 5% better (in annual kWh) thanmonofacial oriented South at latitude tilt angle. YELLOW : at least 5% worse. -5%< GREY <+5%
starting points :• Bifacial double-glass modules resistant to harsh desert conditions (like N-Africa)• Vertical installation may reduce the effects of soiling � ~ 20% performance gain
But ….is vertical installation compatible with the lower geographical lattitudes of these regions ?
vertical ground mounted bifacial systems
Yes ! when oriented East/West and by exploiting the high local albedo
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
14
example : worldmap albedo in May
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
15
close-up of ‘BIFACIAL BELT’ green on map below
• gain upto 30% in the bifacial belt for vertical bifacial E/W orientation
• this adds up with the ~20% expected gain from reduced soiling on vertical modules
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
16
gain bifacial @ vertical compared to monofacial @ lattitude angleGREEN > +5% gain -5% < GREY < +5% gain YELLOW > 5% loss
bifacial back-to-front ratio (BTFR) critical for vertical bifacial performance
BTFR=100% BTFR=90%
BTFR=80% BTFR=55%
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
17
conclusions & perspectives :
Integrated in double-skin facades bifacial modules can offer a 15-20% performance gain over monofacial ones
A half-cell module architecture can offer a gain from 3 to 6% in bifacial modules and allows to reduce sensitivity to non-unform backside irradiance
Linearly textured glass on vertical modules can offer a performance gain of 4 to 6%
Vertical installation in desert areas can take a double-benefit from ground albedo and reduced soiling losses.
Bifacial building integrated PV (‘BI2PV’) remains to be explored and exploited for itscombination of thermal and electrical energy, daylighting and sunshading
Opto-geometrical modelling by Ray-Tracing useful to optimise the optical environment of modules for bifacial and BIPV applications.
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
18
vertical..…WHY ?
30°northsouth
Imp 154 D - INESE.Gerritsen – workshop BIFI PV, May 2014, Chambéry
19
EVOLUTION !
north
east
west
south
Commissariat à l’énergie atomique et aux énergies alternatives
INES RDI | Savoie Technolac – BP332 – 50 avenue du Lac Léman
73377 Le Bourget-du-Lac
T. +33 (0)4 7979 2804
Email : [email protected]
public establishment with industriel et commercial caracter | RCS Paris B 775 685 019
thank you for your attention !
Division of Technological ResearchSolar Technologies DepartmentLaboarorory for PhotoVoltaic Modules
acknowledgements :
• Paul Lefillastre & the INES module team• Yannick Veschetti• Yves Delesse †
• Luc Bernhard (AGC Glass Europe)