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BIPV Solar Explained – Building Integrated Photovoltaics Glass (Efficiency),Curtain Wall,Windows and Technology

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What is BIPV or Building Integrated Photovoltaics and Difference with normal Solar Panels

Building-integrated photovoltaics (BIPV) is integrating of photovoltaic modules into the building envelope such as roofs or windows.These solid-state devices are used to replace conventional building materials  to generate electricity out of sunlight with no maintenance and help in fighting global warming as the produce no pollution.BIPV products are most useful in construction of new buildings as an  ancillary source of electrical power, although existing you can retrofit old buildings with BIPV products as well. The advantage of BIPV over normal standard PV panels is that they integrate into the buildings instead of sticking out leading some people to call it ugly.ALso they help in saving the amount of money  spent on building materials and labor that would normally be used to construct the part of the building . These advantages make BIPV one of the fastest growing segments of the photovoltaic industry with some people estimating that the use of BIPV will increase at more than 50% annually over the next few years with more than 1 GW of BIPV modules installed in the last year.

BIPV Advantages over Solar Panels

1) Aesthitically Pleasing

2) Saves Building Materails and Labor Costs

3) Can be used on weaker building structures and roofs where Solar Panels cannot be installed.

4) Can be used on structures such as Facades,and Skylights where Solar Panels cannot be installed.

BIPV Disadvantages vs PV Modules

1) Higher cost is the biggest disadvantage of BIPV over normal crystalline PV Modules

2) BIPV Efficiency is  Lower as  BIPV modules normally are made of thin film which have lower efficiency.Note crystalline solar panels which are used in BIPV applications on the other hand have no such penalty however they are not generally used in BIPV applications.

3) More complex and requires high labor charges than normal PV modules installation.

4) Difficult and Expensive to Retrofit older buildings.

BIPV Product Types

  1. Thick crystal -These BIPV Products are made from the normal silcion solar cells  and deliver about 13-14watts per square feet.Note the weight of these BIPV products is more and they can be used in limited locations only or structure s which can support the weight of crystalline silicon products
  2. Thin-film – These BIPV products use Thin Film Solar Panle Technology Materals with about 4-5 watts per ft² of PV array area .Note these can be used almsot anywhere as these products are lightweight and flexible.Thin Film modules can be used on  plastic,metal or glass substrates.They can be rolled out on a wide variety of shapes and sizes.The materials are also varied such as CIGs,Cd-Te or Amorphous Thin Film Silcion

What does a BIPV System consist of – Grid Tied and Off Grid BIPV Systems

BIPV Systems like normal Solar Systems can also be grid-tied systems or standalone BIPV systems.Note the cost and complexity of a standalone BIPV system is more than that of a Grid-Tied System.Most of the BIPV systems that are being sold are of power grid integrated types only.Note countries in Europe particularly France and Italy give very generous feed in tariffs for Grid Integrated BIPV systems.Large solar BIPV installations are being developed on greenhouses and roofs of Italy and France to take advantages of these generous government solar subsidies.

A Standalone BIPV Systems consists of 5 parts

1) BIPV Solar Panels or Products

2) A Solar Inverter

3)Solar Charge Controller

4) Energy Storage System

Note this is the same components which go into an off grid solar system with the difference here being the use of BIPV products instead of normal PV modules with their mounting,racking structures etc.

BIPV Shingles (Sharp, Powerflex, Du Pont)

Solar Shingles or BIPV Shingles have become the most important BIPV market segment.These are roof shingles which have PV properties to generate power as well.Dow Corning has made a big splash in the market with its Powerhouse solar shingles which were delayed.Some other companies like Energy Conversion Devices and Sharp already make solar shingles for the roof .Solar Shingle is  a roofing shingle. Solar Shingles install just like asphalt shingles, protecting your roof from rain, snow and is  integrated into your roof. Solar Shingles use Solar Energy to generate electricity just like Solar Panels.Shingles were designed purposefully to blend with your roof. Developed as a Building Integrated Photovoltaic (BIPV) product, they are tough, flexible and thin enough to be a shingle.They can be installed by a roofing contractor, just like regular asphalt shingles. An Integrated electrical connection system eliminates on-roof wiring, with fewer holes drilled into your roof

Types of Solar Shingles

Thin Film Solar Shingles – Thin Film Solar Shingles are Solar Shingles which use Thin  Film Technology which is Copper Indium Gallium Selenium (CIGs) in case of Solar Shingles from Dow and  Energy Conversion Devices.Solar Shingles are made of crystalline Silicon which are sold by Sunpower.Note crystalline silicon solar shingles have much higher efficiency as compared to crystalline silicon.You can read more about Thin Film SolarTechnology and Companies and about the Efficiency of Solar Cells.

Crystalline Solar Shingles – At Present Sunpower is the only company to sell solar shingles made of c-Si on a commercial scale.Though there are a large number of Chinese solar panel manufacturers there are no solar shingle sellers because of the lack of a big market for solar shingles.

Manufacturers of Solar Shingles

  1. Energy Conversion Devices (Uni Solar) – After First Solar,Energy Conversion Devices is the second largest US company in Thin Film Technology.After a few quarters of profits in 2008,the company went into the red as its flexible a-Si modules failed to cut costs as fast as others.It has been shutting factories in the US and shifting to low cost locations.Still one of the biggest independent Thin Film Producers.Seems more likely that it will be bought out then survive independently.The company sells solar shingles mainly in Italy and France.The reason is that those countries give higher subsidy for BIPV applications under which solar shingles made by Uni Solar qualify. PowerShingle is the brand under which Uni Solar sells its solar shingles.
  2.  Dow Chemicals – This Chemicals Conglomerate has started producing it properietary Solar Shingles recently.While the company first showcased its DOW™ POWERHOUSE™ SOLAR SHINGLE in 2009,these solar tiles will be available commercially only this year.Note Dow uses the same thin film technology Copper Indium Gallium Selenide (CIGS) used by UniSolar.The company has delayed the introduction of the solar shingles technology despite developing them as far back as 2009.The company was supposed to start a factory in Brazil.The company claims that the installed cost of Solar Shingles will be lower than solar panels (though its difficult to think that it will be possible with solar panel prices crashing to as low as $1/watt nowadays).It is not know what the Dow Solar Shingles cost will be
  3. Atlantis Energy Systems was founded in 2002 .They manufacture custom solar BIPV Systems (Building Integrated PhotoVoltaic). They  produces solar BIPV glass and solar PVSunSlate Roof Tiles in the USA.
  4. Sunpower (Total) – Sunpower is a vertically integrated solar energy company known more for its highest efficiency solar panels.Sunpower is present in all 3 segments of the solar sytems business namely a)residential b)commercial and c) utility.
    Sunpower makes the highest efficiency, building integrated SunTiles. The SunTile brand blends into flat and S-Tile roofs to convert sunlight into clean energy. SunTiles are all-black and  built to withstand 110 mph wind-driven rain.
  5. Sharp the Japanese Zaibatsu known more for its Electronics Products is also the world’s No 1 Company in terms Solar Module Revenues.Despite its leadership in c-Si Technology,it has shifted focus to a-Si thin film due to higher costs.Sharp has started shipping a-Si modules from its 1 GW capacity plant in Sakai. It also sells solar shingles in the form os 64 watt  solar panels .The Sharp ND62RU1F is a group of solar shingles all arranged together.It is not really a solar shingle since it does not integrate into the roof but its light since its made of  thin film silicon technology and easy to install.

BIPV Organic Solar Products

Konarka Technologies sells  a lightweight, flexible organic solar panel.Konarka’s technology is a photo-reactive polymer material  which can be printed or coated inexpensively onto flexible substrates using roll-to-roll manufacturing.The resulting Power Plastic can then be manufactured into a wide range of end-use products. The company is working with  ThyssenKrupp to develop steel roof and other construction elements for BIPV

BIPV Thin Film Module

There are a number of players that are focusing on producing Thin Film Modules for the BIPV market.Note most of the major Thin Film Producers such as First Solar,Sharp and Solar Frontier makes thin film solar panels for the utility market and don’t have a BIPV range as such.Smaller Thin Film Solar panel companies like Ascent Solar,Konarka are mainly focused on the market.

Ascent Solar WaveSol Thin Film Modules integrate into building materials to produce solar power. WaveSol Light modules  is claimed to deliver the highest power density available on thin-film plastic substrates. Ascent Solar modules laminates can be used  in roofing, shading and building surfaces .They are available in 5 meters for large, flat surfaces; also available in 2 meters with 1 lb/sq ft weight.

What are Photovoltaic membranes

Photovoltaic membranes consist of thin-film  amorphous silicon (a-Si) photovoltaic modules glued on a flexible backsheets. These laminates are then mounted on a synthetic waterproofing membrane for flat roofs.


The cost of BIPV products is not confined to a single number such as $/watt for solar panels.The reason is that a wide variety of products and technologies exist for BIPV.However what can be said is that BIPV today costs almsot 1.5-2x times the cost of standard solar panels.The reason is that the efficiency of BIPV products is generally lower and the integration costs are higher.Most of the bigger and cheaper solar panel producers don’t make BIPV products at all as it is  a smaller market than that of the crystalline solar panel markets.

However BIPV costs are going to go down as larger companies like Dow Corning and Suntech have entered the market.While their products are still at higher prices,they will come down with increasing scale and distribution.

BIPV Curtain Wall

Photovoltaic curtain wall provides a multifunctional solution where energy is generated in-situ, but also natural illumination is provided through solar control by filtering effect.This enhances thermal comfort and avoids interior aging.A BIPV Curtain Wall consists of transparent photovoltaic glass, combined with the aluminum frames.Note BIPV Curtain Wall is generally not used in mass scale like solar panels because they require highly specialized skills and materials.The cost of BIPV Curtain Wall is around $200 per square feet which is doublt that of standard curtain walls.

Features of BIPV Curtain Walls

  1. BIPV Transparent Modules  can be customized in size and thickness
  2. The modules are generally made of thick tempered glass which can withstand high wind loads,temperature variance and snow pressure.
  3. They have a aluminum frames are done aesthetically

Suppliers of Photovoltaic Curtain Walls

Photovoltaic curtain walls

1) Focus Materials has begun to offer its Focus Wall custom-fabricated glass-and-aluminium curtain walls, with built-in semi-transparent thin-film solar technology from Abound Solar, along with vBoost constant-voltage converter modules from eIQ Energy.

2) Konarka Technologies ( see above)

3) Onyx Solar – Onyx Solar is not a solar products manufacturer rather a BIPV Soluation Sller.The copmany focuses in-situ generation of electricity using BIPV products.

Yingli,Suntech and Canadian Solar are some of the major Chinese BIPV sellers.Suntech entered the BIPV products segment when it acquired Japanese installer MSK through which it acquired the MSD Design Line.

BIPV Technology

BIPV Technology is not very different from the normal Photovoltaic Technology as it does not require any fundamental technology changes.More and more solar panel manufacturers are also making solar panels for the BIPV market such as transperant solar panels,double glass tempered solar panels,thin film solar panels for the market (Abound Solar,Ascent Solar etc.).

BIPV Technology is more costly as it requires greater customisation which implies that it cannot be made in standard factory processes.The design and form has to be done by the architect which meants that custom made BIPV solutions will remain a niche product.

For further understanding of Solar Technology Read

Efficiency of Solar Cells and Types of Solar Panels


Abhishek Shah

One Response so far | Have Your Say!

  1. Megha Motiraya

    Double glass/BIPV/Transparent Modules
    Qty – 100 Nos
    MAke – Genko/REC/JA Solar/Resen