1. BIPV represents a strategic part of the
future building vision. BIPV brings the
worlds of construction and photovoltaics
together with all the challenges and
chances inherent to such a change of
paradigm. Aesthetics and technology,
energy efficiency and functionality,
flexibility and reliability are not in conflict
anymore but they are part of the same
concept.
Building
Integrated
Photovoltaics
Systems
Assignment Report
Sudhanshu Anand (CUJ/I/2014/IEE/033)
Submitted to:
Dr. Basudev Pradhan
Asst. Professor, Centre for Energy Engineering
Central University of Jharkhand, Ranchi.
2. 1
Contents
Introduction ............................................................................................................................................2
BIPV Technology Trends .........................................................................................................................2
Prefab mounted BIPV..........................................................................................................................2
Coloured or Patterned Facades ..........................................................................................................3
Solar glazing ........................................................................................................................................3
Lightweight systems............................................................................................................................3
BIPV products..........................................................................................................................................3
Classification of BIPV systems.................................................................................................................4
Roofs ...................................................................................................................................................4
Facades ...............................................................................................................................................5
Potential Opportunities for BIPV Market Growth ..................................................................................5
Installation cost reductions.................................................................................................................5
Improved aesthetics............................................................................................................................5
Higher technical potential...................................................................................................................5
Solar industry interest.........................................................................................................................6
Government support ..........................................................................................................................6
BIPV Price Survey ....................................................................................................................................6
Cost of complete BIPV roof tiling construction...................................................................................6
Cost of facade cladding.......................................................................................................................6
Cost analysis............................................................................................................................................7
Case Study...............................................................................................................................................8
Administrative building “The Edge” Amsterdam (NL) ........................................................................8
The energy concept.............................................................................................................................8
Conclusions .............................................................................................................................................9
3. 2
Introduction
Growing consumer interest in distributed PV technologies and industry competition to reduce
installation costs are stimulating the development of multifunctional PV products that are
integrated with building materials. This emerging solar market segment, known as building-
integrated PV (BIPV), are photovoltaic materials that are used to replace conventional
building materials in parts of the building envelope such as the roof, skylights, or facades. The
advantage of integrated photovoltaics over more common non-integrated systems is that the
initial cost can be offset by reducing the amount spent on building materials and labour that
would normally be used to construct the part of the building that the BIPV modules replace.
These advantages make BIPV one of the fastest growing segments of the photovoltaic
industry. BIPV offers a number of potential benefits, and there have been efforts to develop
cost competitive products for more than 30 years. The deployment of BIPV systems, however,
remains low compared to traditional PV systems. Some building surfaces will have technical
limitations, others will have limited capabilities to generate photovoltaic power due to
inadequate orientation, inclination or shading effect. The assessed BIPV potential thus
comprises the area in the building stock that is suitable for photovoltaic use under
architectural and solar aspects. As with many solar products, the market price of BIPV systems
is a key factor that affects the demand for systems and resulting levels of deployment.
BIPV systems were also considered as building integrated energy storage systems and were
divided into three subgroups:
• BIPV systems with solar battery,
• Grid-connected BIPV systems and
• PV-Trombe wall.
For grid-connected BIPV systems the grid was considered as an infinite cycle battery with
a huge capacity.
The two fundamental research areas in the BIPV systems are observed to be
i) Improvements on system efficiency by ventilation, hence obtaining a higher yield with
lowering the panel temperature
ii) New thin film technologies that are well suited for building integration.
BIPV Technology Trends
Prefab mounted BIPV
This trend has emerged in recent years in Dutch social housing renovation programs. In these
programs, poorly insulated houses are stripped and given a new building skin using well
insulated and prefab constructed façade and roof elements. The use of large prefab elements
is preferred as it allows a very fast building speed and allows people to stay inside their homes
for most of the renovation period. A key challenge here is what level of mechanical stress a
PV panel can handle, and who will be responsible for PV panel (micro)cracking during
transport of the prefab PV elements.
4. 3
Coloured or Patterned Facades
The market demand for PV facades is strongly increasing, on the short term due to the fact
that real estate owners have found out their building value and rental fees increase if it is a
green building, better if proven by BREEAM and LEED certificates. So far, the colouring of PV,
namely its ability to be designed, has been considered an essential requirement for market
acceptance of PV façades. Colouring of PV panels may occur by several different methods like
• Colouring the cells and back sheet
• Colouring the front glass
• Colouring an intermediate foil
Solar glazing
In itself, the technology for semi-transparent PV panels is not new at all. There has not been
yet a breakthrough in technology that suddenly led to a price drop.
However, the combination of glass and photovoltaics, despite their different appearance and
materiality, seems to match well in terms of both aesthetics and functionality of the building
skin and the “BIPV glass” market is expected to grow in the forthcoming years. Moreover,
both in architecture and research perspective, there are many products, flagship buildings,
research projects and some arising innovation trends that represent drivers for a successful
transfer of BIPV glass into the factual built environment. There are several key technological
methods by which solar glazing can be manufactured. The various options are:
• Crystalline silicon glass-glass modules
• Crystalline silicon cell strips
• Thin film solar cell strips
• Thin film solar strips hidden by a lens system
• Luminescent solar concentrators
• Thin absorber layers
Lightweight systems
Two techniques can be distinguished: modules based on thin-film technology and modules
based on crystalline silicon technology. In general, thin film flexible panels have a smaller
curvature radius and are more robust under continuous bending, flapping and moving
conditions. They would therefore be a good choice for applications on boats, tents,
geomembranes, corrugated sheets and the like. Crystalline silicon flexible lightweight panels
are cheaper and higher efficient than their thin film counterparts, but less flexible and less
good looking. They would therefore be a good choice for ‘invisible’ applications with a
permanent fixture, such as flat roofs.
BIPV products
There are four main types of BIPV products:
• Crystalline silicon solar panels for ground-based and rooftop power plant
• Amorphous crystalline silicon thin film solar pv modules which could be hollow, light, red
blue yellow, as glass curtain wall and transparent skylight
5. 4
• CIGS-based (Copper Indium Gallium Selenide) thin film cells on flexible modules
laminated to the building envelope element or the CIGS cells are mounted directly onto
the building envelope substrate
• Double glass solar panels with square cells inside
Building-Integrated Photovoltaic modules are available in several forms:
• Flat roofs
• Pitched roof
• Facade
• Glazing
Transparent and Translucent photovoltaics
Transparent solar panels use a tin-oxide coating on the inner surface of the glass panes to
conduct current out of the cell. The cell contains titanium oxide that is coated with
a photoelectric dye.
Most conventional solar cells use visible and infrared light to generate electricity. In contrast,
the innovative new solar cell also uses ultraviolet radiation. Used to replace conventional
window glass, or placed over the glass, the installation surface area could be large, leading to
potential uses that take advantage of the combined functions of power generation, lighting
and temperature control.
Another name for transparent photovoltaics is “translucent photovoltaics” (they transmit half
the light that falls on them). Similar to inorganic photovoltaics, organic photovoltaics are also
capable of being translucent.
Classification of BIPV systems
BIPV technically refers to systems and concepts in which the photovoltaic element has an
additional building functionality. A functional definition refers to the structural or physical
role of the PV modules in the building skin.
The two main application areas: roof and façades which are shortly described below
Roofs
• Pitched roofs
A pitched/sloped opaque roof is made up of angled and sloped parts. This method of
construction is common all over the world: it is known as a “discontinuous” roof due to the
presence of small elements (tiles, slates, etc.). Simultaneously these small elements have to
hold the main physical building properties such as water tightness. Other important
properties are e.g. fire repellent, storm wind proof, low audible noise from rain showers, and
good acoustic damping. Due to the size of the roof, easiness of install and inclination and
orientation towards the sun, the roof is perfectly suitable for PV.
• Flat & curved roofs
6. 5
A flat or curved roof, also known as “continuous roof”, is characterized by an uninterrupted
layer with the main function to be water resistant. Usually membranes are used as a water
barrier. In the first applications, the PV was mainly placed on top of the roof. Lightweight and
self-bearing systems represent the second generation of PV applications. Flexible
membranes, solar floors and other solutions can easily be used for integrating PV in the
building envelope.
Facades
Increasing requirements regarding energy efficiency in buildings results in a growth of PV
applications in the façade segment. PV acts as a substitute for traditional materials in most
common façade systems (e.g. cold façade or curtain walls), both opaque or transparent.
Moreover, in transparent façades PV has a key role with respect to the comfort of the indoor
microclimate (for reducing overheating in summer and allowing solar gains in winter). Besides
it enhances the comfort due to an increase of natural lighting
The aesthetical definition of BIPV refers to the architectural concept: this is to define in a
unique way. It can be considered as the potential of the PV material/component/system to
define the morphological rules governing the signs, the structure and the composition of the
building’s architectural language. Some of the options are:
• Mounting systems (partially integrated)
• Full Roof solution (totally integrated)
• Prefab systems
• Solar tiles
• Lightweight systems
• Rain-screen façade (cold façade)
• Curtain wall (warm façade)
• Skylight/ Solar glazing
Potential Opportunities for BIPV Market Growth
Installation cost reductions
• Lower non-module costs – elimination of racking hardware, and greater use of
traditional roofing labour and installation methods
• Cost offsets for displacing traditional building materials
• Lower supply chain costs – leverage more established channels to market
Improved aesthetics
• Consumer willingness to pay premiums in some markets
• Broader appeal for residential solar product designs
Higher technical potential
• Increased PV-suitable space on buildings
7. 6
Solar industry interest
• Showcase applications
• High growth potential
• Technology differentiation may help suppliers distinguish themselves
• Possible cost reductions and new channels to market
Government support
• Maintain historic/cultural building designs
• BIPV-specific incentives in select international markets
BIPV Price Survey
The economic sustainability of BIPV technology is a crucial aspect of its feasibility and market
success. So far the main efforts towards cost-effectiveness have been focused, similarly to
conventional PV, on minimizing the final installation price per kWp that usually is the price of
the installed and functioning system, including design, materials, mounting, tests and labour
(building and electrical).
Cost of complete BIPV roof tiling construction
The graph refers to the final cost of a complete roof tiling construction, including mounting,
transportation and other additional costs. This cost includes both the roof tiling and the
mounting system (clamp, metal ducts, etc.).
Cost of facade cladding
The prices for conventional façade applications were obtained using Swiss databases on
building price information. The graph specifically refers to the cost of the cladding, namely
the outer material layer that represent the exterior wall. The costs of the substructures,
fixings and insulation are excluded for the conventional building material.
8. 7
Cost analysis
On building with a medium to low architectural quality, installing a photovoltaic plant in
concurrence with the indispensable (energy) refurbishment interventions, can significantly
reduce the economic impact. In fact, basic costs such as on-site installation, scaffolding/
movable safety parapets, administrative procedures, works coordination, etc. are divided on
several interventions and therefore have a lower impact on the cost of the photovoltaic
installation.
9. 8
Case Study
Administrative building “The Edge” Amsterdam (NL)
• Project overview
• Location: Gustav Mahlerlaan 2930-2970, 1081 Amsterdam.
• Completion Year: 2014
• Architect: PLP Architects
• Typology: Office building
• Category: New building
• Surrounding: Urban
• Installed PV power:
Façade: 100 kWp
Rooftop: 190 kWp
Rooftop nearby buildings: 640 kWp
• Orientation:
Facade: South
• Dimensions:
Facade: 720m2
Rooftop: 1200m²
Rooftop nearby buildings: 4100m²
The energy concept
The building is entirely energy-neutral. In the Building, photovoltaic panels have been applied
at three levels: at the façade, at the rooftop and at the rooftop of two buildings in the near
10. 9
vicinity (within 10 km). The total installed capacity is enough to fulfil the total electrical
demand of the building. The electrical energy that is generated by the Solar cells on the
rooftop is directly used for the installation of the heat and cold storage. The remaining
igenerated electricity is mainly used for the low-energy LEDs, all laptops and smartphones in
the building and all electric powered vehicles, used by employees. The current energy
consumption is now estimated to be -0.3 kWh/m2/yr.
Conclusions
• More complex technology and design issues and relatively small-scale production
capacity of BIPV likely may result in continued price disadvantages compared with
rack-mounted PV systems
• Success of many residential rooftop BIPV products may hinge on the aesthetic value
of product designs and a consumer willingness to pay premiums for non-traditional
systems.
• Different analysis supports the notion that BIPV has the potential to reduce the
installed system prices of comparable rack-mounted PV in residential rooftop
markets. Market experiences suggest, however, that realizing these opportunities can
be challenging.
• Multi-functionality, cost effectiveness, mass customization and other paradigms are
ensuring a growing penetration of the technology itself, but beyond functional and
energy aspects, BIPV is slowly becoming part of the architectural concept.
• BIPV is affordable and that the extra cost compared to normal building materials,
especially on the high-end spectrum, is limited.
• There was no big price drop compared to 2 years ago in BIPV industry.
• Overall, the BIPV sector is in a healthy shape. Many attractive products are available,
reliable and offered at a competitive price.