This presentation examines the different array of options for integrating photovoltaic devices into buildings.

1. Advances in Building Integrated
Photovoltaic Technology:
With Implications for Wales
Gavin D. J.
Harper
g.harper@glyndwr.ac.uk
@gavindjharper
www.gavindjharper.com
http://orcid.org/0000-0002-4691-6642
Regional Science Association International – British & Irish Section
43rd Annual Conference & Doctoral Colloquium,
Aberystwyth, Wales
19th – 21st August 2014

2. What is BIPV?

3. What is BIPV?
• The principle of BIPV is that PV modules are
incorporated into the building envelope,
substituting standard glass and other
cladding materials.
• This has the potential to result in
environmental savings through reduction of
duplication of materials and shared
functionality.
• It may also lead to cost savings over
separate PV and building materials.

4. How is it integrated?
• Additional / superimposed
• Added to the structure of the building with the primary function
of generating energy. Sometimes referred to as ‘building-applied
PV (BAPV)
• Integrated
• Components are replaced with PV generating materials that
serve both purposes
• Standalone
• Solar PV array is discreet and separate eg parking shading

5. Where is it integrated?
•Façade
• as part of the fabric or as an additional
wall
•Rooftops
• sloping or flat
•Glazing
• integrated into the window requirement

6. Why BIPV?
For Wales and the wider UK

7. BIPV – the global market
• Navigant Research estimate the BIPV market to be worth $2.4 Billion by
2017
• They expect the BIPV total capacity to quintuple in the same time
• Other sources (Accenture Plc) see the solar glass market alone being
worth $4.2 Billion
• New markets continue to emerge and existing markets expanding.
Middle East is placing more onus upon energy and Far East is following
close behind
• As energy prices continue to rise and LEED and BREEAM become more
mainstream (as well as Zero Carbon buildings), the appeal of BIPV will
continue to grow. More mainstream BIPV will become more the norm
and newer versions will help create signature buildings with their novel
properties

9. Solar Roadmap Part II (page 17)
• While it is impossible to quantify the potential,
building integrated PV (BIPV) would push the
maximum capacity which can be deployed
on roofs higher than that achievable with
conventional PV panels alone.
•UK companies strongly represented in BIPV
supply chain.
• Encouraging deployment on buildings in the
UK should help to boost this emerging sector,
which has enormous potential globally.”

10. Solar Roadmap Part II (page 28)
• The UK has a vibrant Building Integrated PV (BIPV)
sector, where the building fabric is made from
solar PV materials.
• Technology is starting to provide us with the
opportunity to install PV directly into the fabric of
building glass and cladding material.
• These products will allow architects designing
new buildings to maximise the energy generation
of the fabric of the building.
• Costs of BIPV products have fallen at a similar
rate to conventional modules, as they share the
same solar cells.
• BIPV looks set to be an exciting area of growth.

11. Solar Roadmap Part II (page 29)
• The market for BIPV products will provide opportunities for
UK companies to develop and manufacture these
products, which look to provide welcome export
opportunities.
• BIPV also provides opportunities for next generation solar
PV materials to develop (e.g. Polysolar, Oxford PV) and be
brought to the market through the substantial building
industry supply chain.

12. Wales: Competing with China?

13. Solar Roadmap Part II (page 38)
• So far, the PV sector has been dominated by one
technology (c-Si) and one product (the flat photovoltaic
module).
• This has triggered significant cost reductions in
manufacturing but not a major change in the way in
which the PV technology can be deployed and used.
• That step change could be harnessed through innovation
of new technologies and improving integration to UK grid
and the development of associated technologies.
• That said, crystalline silicon (c-Si) is expected to remain the
top PV technology in the coming years.

14. Solar Roadmap Part II (page 38)
• The UK, together with more established countries’ PV
markets such as Germany, Italy or the US, could see a
differentiated opportunity to that of China and Asia-
Pacific countries to develop innovative products (e.g.
BIPV; thin film, and printable organic PV)
• The UK has well-established research and development
activity on a range of photovoltaic technologies and
applications, which are predominately focussed on next
generation technologies.
• This may provide a comparative advantage.

15. Solar Roadmap Part II (page 56)
• With BIPV coming through, as a specialist product more likely
to be made in the UK, the jobs component could be
substantial. Conventional PV systems have supply chains that
are heavily dependent on imported product from outside the
UK.
• The major contribution to the UK supply chain is through
development, installation and maintenance.
• However, BIPV is currently more likely to be manufactured in UK
through companies such as Romag, Kingspan and others.
• The high technology BIPV exemplified by the glass and façade
products under development by Oxford PV and Polysolar is yet
to be industrialised in the mainstream, and there is therefore a
significant opportunity to encourage the growth of a strong UK
industrial base.

16. PV in Wales
Regional Strengths
Commercialisation
& Manufacture
Centre for Solar Energy
Research (CSER) @
OpTIC Glyndwr
Expertise in thin-film,
Cadmium Telluride cells.
Expertise in novel
MOCVD process &
advanced optics.
GB Sol, PV Module
manufacture.
Mounting Systems
Manufacture.
G24i Manufacturer of dye
sensitised solar cells.
Bangor University
Dye sensitised cell
research Sharp Silicon Module
Manufacture.
SPECIFIC, Swansea University
Ser Solar, Swansea University
PV Research
Pure Wafer (Reclaimed Silicon
Wafers)
Dyesol BIPVCo
IQE Multijuction PV (Concentrators)

17. PV Technology Pathways
Does Wales Regional Strength Lie in Technological Diversity?

18. Photovoltaic Technology Options
Photovoltaics
1st Generation
(Silicon)
Monocrystalline
Mono c-Si
Polycrystalline
Poly c-Si
2nd Generation
(Thin Film
Cadmium Telluride
(CdTe)
Copper indium
gallium (di)selenide
(CIGS)
Gallium Arsenide
3rd Generation
(Organic &
Excitonic)
Dye Sensitised Solar
Cells (Grätzel Cells)

19. Comparing Photovoltaic Technologies
• Thin film technologies compete on the basis of slightly less
efficiency, but at a lower cost / kW
• Slightly less efficient per unit area. But better at capturing diffuse
light – so potentially well suited to Welsh climate.
• Seen as a “substitute product” rarely the default choice.
• Crystalline silicon raw materials cost around 20%. For thin film, figure
is 10%
• Crystalline silicon manufacturing technology is “commodified”
whereas thin film manufacturing technology is proprietary.
• Efficiency of cell technologies directly impacts the cost of installed
technologies, improvements in thin-film performance improve
competitive position.

20. Thin Film / Excitonic Cells:
Continuous Production?
Crystalline Silicon Cells
“Batch” Production
Thin Film / Excitonic / DSC Cells
“Reel to Reel” Production
Image: Sharp, Llay Wrexham, Silicon Cell ProdImuacgtioen: G24i Power, DSC Cell Production

21. BIPV Design Considerations

22. Environmental Factors
• Insolation available
• Climate & weather conditions
• High ambient temperature will reduce PV output
• Local atmospherics such as cloud can impact
• Pollution of any form can require cleaning
• Shading
• Latitude (affecting optimal angle of PV
panels)

28. • “What we are saying that if you have the solar panels facing
east-west then you can even out the power during the day.
You may lose about 10 per cent of power if you go east-west
but this addresses a problem that exists in Germany where
because everything is facing south, you get this peak power at
midday which is very difficult for the grid to cope with.
• “So in Germany they are advising people to go east-west so
they are smoothing out the supply of power from all these solar
panels. We get similar spikes of power too, although it wouldn’t
make sense for people to change their solar panels if they
have already been installed.
• “In total we have 2.8 Gigawatts of solar in the UK but Germany
has approaching 20 Gigawatts. In Cornwall they can’t install
any more solar panels because the grid can't handle it.”
Prof. Michael Wallis,
Loughborough
University

29. BIPV Building Technologies

30. Bifacial PV Cells
• Cells encapsulated within glass, allowing light to be
captured from both sides of the cell.
• This improves the efficiency of the cell.
• Bifacial cells are prized for their aesthetic properties, and
are often used on canopies of shades.
• They are useful architecturally as they allow some light
through to the area below, but also provide shading.
• Bifacial cells offer a 25-80% energy power advantage1
over monofacial cells.
1.http://www.nrel.gov/technologytransfer/pdfs/igf20_gamma.

31. Glass PV roof
• Using the glass PV panel itself to form the surface of the
roof

32. Glass PV roof
Striking when used in large areas

33. PV Skylights
Range of interesting ‘transparent’
thin film and organic technology
trajectories.
Onyxsolar.com

34. PV Skylights cont.
• These can be installed as the skylight glass itself
• An alternative is as an additional layer over the skylight
itself. This has the added bonus of ease of
maintenance/repair and added insulation and cooling
• PV’s can either be:
• Opaque, with clear glazing between adjacent cells allowing light
through.
• Semi-transparent – DSC technologies and suchlike, which allow
some light through.
• Newer technologies promise “see through” photovoltaics, which
attenuate the light, but allow for clear vision.

35. PV Canopy
gepower.com

36. PV Canopy
• One of the simplest installations Gaining popularity in
warmer climes where shading of parking is often normal
• Visibly promotes charging of cars (if a charging point is
fitted) and gives visitors an early indicator of company
ethics
Silicon
Based
Bifacial Cell
onyxsolar.com

37. Dye Sensitised / Semi Transparent

38. PV Building Façade
• Designed as a façade that generates energy as
well as performing as a façade
• In this example, the manufacturer (ruukki.com)
provides a complete mounting system with
studs, flashings, fasteners and electrical
components. There are no visible cables and no
wall penetration for the electrical install (easier
to install and maintain)

39. PV Building Façade cont.
M9 ARCHITEKTEN Senfter + Lanzinger
Schott Solar
EWE Arena Oldenburg
, colt 2009

40. PV Building Façade cont.
• As on the previous page, the façade can be used to
provide shading to the occupants
• Shading can be constant, intermittent, fixed or movable, such as
these examples of brise soleil
ertex-solar.at

41. • Retrofit can be used
to improve the
quality of the built
environment.
• Many buildings with
system built
concrete / exposed
finishes. Structurally
sound, but exterior
facades suffer from
spalling.
• PV offers an
attractive solution.

42. Price of façade materials (2011)
• Figures based on Odersun products and are Euro per m2

43. Brise Soleil
• This is not a picture of a solar
installation.
• These are plain old boring Brise
Soleil!
• BUT, illustrates an interesting
point.
• City centre school in Nimes (France)
• Unintended consequences
• Kids use as a climbing frame!

44. Spandrels and Parapets
• Spandrels are part of the exterior wall of a building
(between the floor and the bottom edge of the window).
• Parapets are waist-high barriers at the edge of balconies,
bridges, etc. Semitransparent PV modules integrated into
spandrels/parapets can obscure the view of the inside,
while allowing a free view of the outside.
• Structurally, they have the properties of laminated glass
and can be used to create attractive accents on the
façade (solarfassade.info)

45. Spandrels
syracuseglass.com archpaper.com
bisem-usa.com

46. Parapets / Balconys
kolumbus.fi
solarbuildingtech.com

47. Solar PV Rooftops
• The standard rooftop mounting available:
• Parallel to roof
• Angled mount
imetco.com
asera.net

48. Solar Roof Slates
Images courtesy: Solar Century
• C21 Solar slates.
• Integrate with cost-effective concrete tile system
• Low visual impact, aesthetically pleasing.

49. Solar shingle
• Dow are marketing solar integrated shingles in the US
under the name Powerhouse

50. Thin film roof PV
• Flexible thin film modules
laminated to a roof
membrane
• Lower efficiency than rigid,
but more flexible in location
altenergymag.com

51. Direct mount PV
• By tweaking the design of regular PV panels, a direct
mount that negates many mounting problems / wind load
etc
lumetasolar.com

52. Direct mount PV
• If this mode of PV deployment were to
be included in the design phase, savings
could be made
•Roof load would be lower reducing
requirement
• Elimination of fixtures, removing cost and
speeding build
• Less wind load issues as PV is flush to the
roof

53. Direct mount PV
•Including the PV as part of the sawtooth /
northlight design. Alignment complements
both aspects.
solarfassade.info

54. Who do you need to involve for
a successful design?
• BIPV manufacturer
• Architect
• Project manager
• Structural engineer
• Electrical engineer
• Building shell designer
• Façade / roof contractor
Opportunity
for firms
offering an
approach
that
holistically
integrates
professions
and trades.

55. What other functions could BIPV perform?
• Privacy screening
• Solar protection
• Architectural design element
• Heating
• Thermal insulation
• Weather protection
• Residual structural support
• Burglary protection (toughened glass)
• Sound protection and insulation

56. Conclusion
• There is a global future for BIPV
• It is growing
• It will remain focused upon the primary areas of façade,
roof, spandrels, parapets and balconies
• Increasing energy efficiency and carbon reduction
measures will drive demand, as will improved PV efficiency
AND innovation in the field
• Success will come from the integration of the BIPV into the
construction process and the building itself, so a
partnership with façade / roof manufacturers and/or
those providing the mounting systems would seem optimal

57. If you found any of this interesting…
Please stay in touch
Gavin Harper
g.harper@glyndwr.ac.uk
www.gavindharper.com
http://www.cser.org.uk/
@gavindjharper
@CSER_PV
@LCRI_WEST
https://www.westproject.org.uk/