GB2506430A - Building exterior façade display formed from combined OLED and PV solar panel. - Google Patents

Abstract

A display for the exterior façade of a building comprises an OLED panel which incorporates a photovoltaic (PV) solar panel. The OLED and PV panel are both formed as transparent layers on a transparent substrate, e.g. glass. The display may also incorporate a battery formed as a further transparent layer. The display can be used for movies, images, advertising or to transform the appearance of the building. The display may be formed as a glass panel for use as a building curtain wall. The solar panel may be a dye-sensitised solar cell (DSSC).

Description

Introduction:

The invention is an innovative BIPV media façade utilizing photovoltaic and OLED technologies. The unit can power itself and generate excess power to be utilized in the building or feed back into the grid. The unit is transparent when non operational and can display moving televisual and graphic images when in operation. The unit can display advertising or change the appearance of the entire envelope depending on the end users requirements.

There are several key movers that are influencing this invention. These are the PV industry and the now reduced feed in tariffs and advertising revenue, these will be introduced below and discussed through the following chapters.

The need for green building and the introduction of BREEAM excellence ratings has resulted in energy efficiency, green energy production and reduced carbon foot print becoming very high priority considerations. These demands are backed up by the requirements of the Kyoto protocol, the Energy Performance in Buildings Directive, the general international and national need for low carbon buildings and the increasing demand for a green built environment.

The following articles show the requirement for change: With the ever-changing requirements of Building regulations Part L the conservation of fuel and power it has become a requirement to achieve increased performance standards.

Carbon dioxide emissions from housing contribute some 27% of the UK's total and so it is right that the energy performance of new homes is addressed and improved.

Successive Governments have shown a commitment to the 2016 zero carbon target for new homes and an important step towards that target was taken in October 2010 with the introduction of the consolidated Building Regulations and revised Approved Document L. (NHBC Foundation, 2010) On the international stage the Kyoto Protocol is an international agreement working with United Nations tackling Climate Change. The Kyoto Protocol sets targets for 37 industrialized countries and Europe for reducing greenhouse gas (GHG) emissions and reduce carbon footprint.

Under the terms of the Durban Platform agreed at last year's UN climate summit, the EU said it would sign on to an extension of the Kyoto protocol before it lapses at the end of this year in return for an agreement from all nations that a new binding treaty will be finalised by 2015 and enacted by 2020.

(James Murray Business Green, 1 6th May 2012 Original source -European U nion Public Announcement, 9th March 2012) Various bodies have been set up to evaluate the performance in commercial and residential building.

The EU Energy Performance of Buildings Directive (EPBD) was introduced in the UK from January 2006 with a three year implementation period ending January 2009. Its objective is to improve energy efficiency and reduce carbon emissions as part of the government's strategy to achieve a sustainable environment and meet climate change targets agreed under the Kyoto Protocol. The EPBD introduced higher standards of energy conservation for new and refurbished buildings from April 2006 and will require energy performance certification for all buildings when sold or leased.

In addition it will introduce regular inspections for larger air conditioning systems and advice on more efficient boiler operation for commercial property.

(Royal Institute of chartered surveyors, June 2007) One of the most recognized companies worldwide assessing the performance of buildings is B RE EAM.

BRE Global act as advisors on issues related to maintenance and development of the technical contents of the CSH standard and manage implementation of the scheme under contract to the Department of Communities and Local Government (DCLG).

Scope and Scoring The CSH covers nine categories of sustainable design: * Energy and CO2 emissions (M), * Water (M), * Materials (M), * Surface Water Run-off (M), * Waste (M), * Pollution, * Health and Wellbeing (M), U Management, * Ecology.

There are mandatory performance requirements in 6 categories (denoted by an M above). All other performance requirements are flexible. It is possible to achieve an overall level of between zero and six depending on the mandatory standards and proportion of flexible standards achieved.

Once the overall score for the building is known this is translated into a rating on a scale of: -Pass -Good -Very Good -Excellent -Outstanding A star rating from 1 to 5 stars is also provided: (BRE Global, 2011) As a result of the above energy performance is imperative for the overall efficiency, low carbon foot print and financial running cost for the life of the building.

Energy Efficiency is self explanatory; reflecting how effectively energy that is needed around the property is used. A higher rating means a more effective use of energy.

Environmental Impact is essentially a measurement of how much Carbon Dioxide is emitted from the property. The higher a rating on the Environmental Impact rating; the less C02 is emitted.

EPC's showthe current and potential energy usage of a property through the government's approved Standard Assessment Procedure (SAP). The basic underpinning of the SAP Rating is points based system ranging from 0 to 100. When a property has an EPC assessment it is given a SAP rating score within this margin, higher scores denoting more efficiency.

EPC Bands The SAP bands have been divided into seven categories that summarise a property's energy efficiency and environmental impact.

* A: 92-1 00 SAP Points * B: 81-91 SAP Points * C: 69-80 SAP Points * D: 55-68 SAP Points -SOLAR FIT MINIMUM * F: 39-54 SAP Points * F: 21-38 SAP Points * G: 1-20 SAP Points The DECC have established that a property must have a minimum EPC rating of category D' in order to receive the full Eli's. If a property has solar panels installed after April 1st, 2012 and has a lower EPC rating than 0', it will only be eligible for a generation tariff rate maximum of 9 pence per kWh. Basically, it is not a wise move to install solar under such circumstances; so all properties installing solar after April 1st 2012 should aim to have their ECP ratings above D' before doing so.

(Jarrah Harburn, 2012) As a result of this vast improvements have been made in the PV photovoltaic industries.

These improvements have a direct correlation to Building integrated photovoltaic's BIPV.

This study ill show how thin film PV's for example are revolutionizing the PV market.

LONDON --Building-integrated photovoltaics (BIPV) currently make up a small but increasing part of the world PV market, and many analysts predict a growth explosion in the sector, resulting in a multibillion-dollar annual market segment. The global BIPV market was estimated at 1201 MW in 2010 and is expected to increase at a 56% compound annual growth rate (CAGR) to reach a capacity of 11,392 MW in 2015, according to Building-Integrated Photovoltaic's (BIPV): Technologies and Global Markets, a new report from analysis firm BCC Research (Renewable Energy World Network Editors, 41h Nov 2011) Jeremy Watson, a director of global research at Arup and chief scientific adviser for the Department for Communities and Local Government, says that renewables will have a bigger role to play in the sustainable building of 2012. "Speaking from a personal perspective, I think that, notwithstanding the reduction in feed-in tariffs (FITs), the drop in PV prices and the introduction of the Renewable Heat Incentive will mean micro-renewables becoming increasingly viable,"

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He says the big multi-nationals have already got the message on the need to cut energy consumption and so developers are starting to get the message. "Developers know the existing building stock will become unattractive to let in five years' time if it hasn't got the right energy performance criteria." (Andy Pearson, June 2012) The design, aesthetic appeal and advertising shown via the media façade is imperative.

Organizations such as The SEGD Global Design Awards were established in 1987 to recognize excellence in environmental graphic design and cover these innovative display systems in our environment and public spaces.

In today's consumer society advertising and selling of advertising space is big business.

With such land marks as Piccadilly square in London or Times square in New York there is no doubt with the correct location and technology large amounts of revenue can be made with media facades.

The additional advantage to this technology is that it can change the appearance of the building through colour, graphic, televisual display and be capable of large scale dynamic advertising. The external appearance of the building could be changed almost at will during both the day and night. The system could simply mimic a finish or style, stone, brick or Gothic to Georgian for example.

Media façades have blossomed in many directions, with great promise to LED display screen manufacturers, sign integrators, architects, media planners and urban developers, who recognize how this super sized signage enhances the urban landscape. Bottom line, signage has media façades covered. "The integration of media façades in a building structure is transforming how architecture creates buildings," said Tom Powley, president of GKD-USA, a Cambridge, MD branch of the Duren, Germany based manufacturer of Mediamesh, a metallic woven fabric with an embedded, LED display screen that covers building façades. GKD collaborates with Cologne, Germany-based "ag4", which invented Mediamesh, in providing media-façade architectural solutions for various applications.

Powley said, "The creation of a media façade on a building allows the building to come alive with imaging and lighting, which changes how it relates to its surrounding cityscape. This is a development of corporate branding and corporate identity programs, creating its highest and most visible presence. This, in effect, is a new era for corporate LED display screens." Media façades' LED display screens allowcorporations to communicate their identities in public spaces. Two recent "ag4" projects highlighted in the article demonstrate "mediatecture" designs and the structural integration that links the media façade into its surrounding cityscape. Successful media façades match the building project with the appropriate LED display screen of media façade to cover the building.

(Louis M.Brill, 6/2008) The combination of the above will create a façade system that would produce its own energy via PV and change appearance through OLEDs. This would in turn create a revenue stream through FIT's and advertising. The system would also achieve high performance through its composition and makeup of the individual components, achieving high ratings for impact, thermal and acoustics'.

The current best practis doesn't achieve, graphic televisual, photovoltaic power generation, thermal, acoustic or loading requirements. There will be an evaluation of the potential for further development and the technical feasibility and identification of key performance criteria that need to be considered. The elements required for the BIPV panel prototype construction to follow.

Review the current best practice and state of the art relating to façade integrated PV In the solar core thermonuclear fusion reactions take place continuously at extremely high temperatures and release huge amounts of energy in the form of electromagnetic radiations.

The spectium of the radiations is known as the electromagnetic spectrum and it has a veiy broad range of frequencies. Only a very small amount of this spectrum is visible to the human eye in the form of light.

Fig 2.0 Light spectrum Source: Wikispace Albeit Einstein was awarded the Nobel Prize for Physics in 1921 not because of his work associated ith the theory of relativity but for explaining the photoelectric effect. He postulated that light is made up of packets of energy called photons. Photons have no mass but they have momentum and they have energy, the magnitude of which is given by the formula Energy of a photon: E = hf Where h = Plancks constant F = trequency of radiation It follows from the above that different radiation wavelengths contain an amount of energy proportional to the frequency.

When passing through the earth's atmosphere, the solar radiation diminishes in intensity because it is partially reflected and absorbed, most notably by water vapour and other atmospheric gases and diffused by air and the solid particles suspended in air.

The photoelectric effect occurs when a photon strikes an object causing an amount of energy to be absorbed. A certain minimum amount of energy is needed to eject an electron from the material surface. This value of energy is known as the work function and is a characteristic of the particular material. If a photon has an energy equivalent to or greater than the work function, an election will always obtain sufficient energy to escape from the surface of the material. It is evident from the above formula that the minimum work function occurs at a specific radiation frequency and this value is known as the threshold frequency for a particular material. Different materials exhibit different threshold values.

The electrons are released from the valence band on the outer shell of the atoms into the conduction band which is the unoccupied orbital path of the atoms. It is possible for the elections in the conduction band to return to the valence band, a process known as recombination. This would adversely affect the photoelectric process and should be prevented. This can be achieved by separating the bands with an electric field from, for example, a battery with positive and negative terminal. This arrangement allows the released electrons to travel in a circuit giving rise to a voltage.

This is known as the photovoltaic effect.

Early first generation solar cells included an electrical field using a PN junction; later designs created the electric field by other methods which are detailed elsewhere in this document.

FIRST GENERATION SOLAR CELLS

The majority of first generation solar cells use silicon owing to its availability, the fact that it has a low threshold frequency relative to other materials and remains a semi conductor at high temperature and also that it can be disposed of in an environmentally friendly manner.

The solar cells can be divided into two categories, one using single monocrystalline silicon and the second using polycrystalline silicon.

Monocrystal panels include silicon crystal of very high purity. The single crystal silicon ingot has cylindrical form, typically 13 to 20 centimetres in diameter and 200 centimetre length obtained by the growth of a filiform crystal in slow rotation. The grown cylinder is then sliced into wafers typically 200 -250 micrometers thick and the upper surface is treated to obtain microgrooves" aimed at minimising the reflection losses. Panels including this technology are usually characterised by a homogenous dark blue appearance.

Fig 2.1 Crystalline solar cell Source: AC Solar The crystals constituting the cells of polycrystalline silicon panels aggregate, taking different forms and directions. The ingot is obtained by melting and casting the silicon into a parallelepiped shaped mould with the ensuing wafers being typically 180 -300 micrometers thick and square shaped. Panels using this technology display iridescence due to the various directions of the crystal grain and the consequent behaviour with respect to light.

Both the above categories of solar cell include two silicon layers with a thickness of approximately 0.3 millimetres. Silicon has four valence electrons which normally bond with four neighbouring atoms to form a stable uniform structure. The properties of the structure can be changed by the addition of impurities, a process known as "doping".

Typically boron with three valence electrons (P doping) is added on one layer thereby making one of the covalent bonds incomplete resulting in an excess of holes and making the boron an electron acceptor. The adjacent layer is doped with five valence electrons such a phosphorous (N doping) resulting in an excess of electrons rendering the phosphorous an electron donor.

In the contact area between the two differently doped layers, the P-N junction, the electrons tend to move from the electron rich half N to the electron poor half P, resulting in an accumulation of negative charges in the P legion. The electron holes create a positive charge in the N legion resulting in an electric field across the junction which opposes the further diffusion of electric charges. The application of an external voltage across the junction allows the current to flow in one direction only.

When the cell is exposed to light, the photovoltaic effect causes some electron-hole couples to arise in both N and P regions. The internal electric field allows the excess electrons, cleated by the energy from photons, to be separated from the holes and pushed in opposite directions relative to one another. Once the electrons have passed the depletion region, the field prevents them from moving in the reverse direction. If the junction is connected to an external conductor, a closed circuit is obtained with the current flowing from layer P, with high potential, to layer N, of lower potential. This will continue as long as the assembly is illuminated and in receipt of protons.

Cells are normally encased into a module to be used as part of the assembly system and which is designed to * Electrically insulate the cells towards the outside * Protect the cells against atmospheric agents, severe weather and mechanical stresses * Resists ultra violet rays, excessive temperatures, sudden changes of temperature and abrasion * Dissipates heat quickly to prevent temperature rise reducing the power of the module In order to achieve the above a typical standard module with silicon cells would be assembled from * A protective high transparency tempered glass sheet on the upper side * An encapsulation material to avoid direct contact between glass and cell, to eliminate the interstices due to surface imperfection of the cells and to electrically insulate the shell from the rest of the panel.

* A supporting substratum panel, either glass, metal or plastic on the lower side * A metal frame, typically aluminium.

Connection of silicon cells is usually achieved via metallic contacts soldered after construction of the cell

SECOND GENERATION SOLAR CELLS

This type of cell, known as the thin film solar cell, was developed to replace the silicon cells described above. Although the technology continues to advance, it has not yet proved possible to achieve the same efficiency of silicon cells on a consistent basis. It is likely that the main advantage will be significant reduction in manufacturing costs attributable to mass pioduction.

There are several types of photovoltaic material that can be effectively deposited onto various substrates and this arrangement normally categorises a thin film solar cell. The cells comprise a semi conducting material deposited, usually as gas mixtures, on supports such as glass, polymers, aluminium etc, which give physical consistency to the mixture. The film layer is typically a few micrometers thick as opposed to a few hundred micrometers of silicon in first generation cells, iesulting a significant mateiial and cost saving. The use of a flexible support is also a practical possibility increasing the application field of this technology.

The materials currently used in thin film applications are * Amorphous silicon (a-Si) * Cadmium Telluride-Cadmium Sulphide (CdTeS) * Gallium Arsenide (GaAs) * Copper Iridium Diselenide alloys (CIS, CIGS and CIGSS) Amorphous Silicon deposited as a film on a suitable support offers reduced cost of PV technology relative to crystalline silicon but the cell efficiency deteriorates ith time. The material can be sprayed onto thin flexible bases to reduce the weight of the assembly and make it suitable foi curved suifaces. The efficiency is veiy low because of resistance of the flux on electrons.

Fig 2.3 a-Si PV Source: Panasonic The efficiency and endurance of the assembly can be increased by combining the amorphous silicon layer with one or more multi junction crystalline silicon layers. Thanks to the separation of the solar spectrum, each junction positioned in sequence works at a high level thereby increasing the efficiency and endurance.

Cadmium Teluride-Cadmium Sulphide cells comprise one P layer (CdTe) and one N layer (CdS) which creates a P -N junction allovAng an electrical field to form. These cells have a higher efficiency than amorphous silicon units but the production, use and recycling of CdTe in particular gives rise to real concerns. This does have some toxic properties though it is deemed safe when enclosed in the cell. Any leakage, whether due to accident, building collapse, fire etc needs to be very seriously considered before integration of these panels.

Recycling could also be an issue because it is not soluble in water and is more stable than most cadmium compounds.

Fig 2.4 CIGS PV Source: All about circuits Gallium Arsenide technology is a very interesting concept when considered from the point of obtained efficiency, typically in the excess of 30%. The production of such cells is likely to continue to be limited by the high costs and scarcity of the material which is primarily used in the high speed semi conductor and optoelectronics industries, neither of which are as price sensitive as the market for solar cells. The technology is also used in space and aeronautic applications where dimensions and weight are important and it is unlikely to be used in any significant way for other commercial applications.

Fig 2.5 GaAs PV Source: Green energy build Cells using various combinations of copper, iridium and diselenide alloys appear to be capable of achieving the efficiency of polycrystalline solar cells. A reduction in the production cost is foreseen and this type of cell may become more available in the future.

Fig 2.6 CdTe and CIGS Source: Advance energy The market share for thin film panels remains limited but reductions in manufacturing costs are deemed to be achievable. The direct deposition of a thin film reduces waste to a negligible amount and the processes are low power consumption reducing costs and payback time. In comparison with silicon modules, thin film assemblies exhibit a lower effect on efficiency by the operating temperature and increased performance in diffused light when radiation levels are low.

THIRD GENERATION SOLAR CELLS

First generation solar cells using silicon have been the market leader for several years. Cost of manufacture and the reducing availability of high quality silicon have been the prime movers towards the second generation cells but only at the cost of efficiency although technology advancements are increasing the efficiency under laboratory conditions.

Third generation solar cells are intended to eliminate the shortcomings of the previous designs whilst also drastically decreasing the cost of production. The general approach is to achieve high efficiency low cost cells that use thin film second generation deposition methods. Most of the technological progress is at the development stage and five methods to achieve the aims are presently receiving aftention.

Multi junction cells use multiple band gaps that selectively absorb different regions of the solar spectrum.

Intermediate band cells use one junction ith multiple band gaps to increase efficiency.

Hot carrier cells convert the excess energy of the above band gap photons into electrical energy.

Spectrum conversion cells convert the incoming polychromatic sunlight into a narrower distribution of photons suited to the band gap of the solar cell.

Dye sensitised solar cells (DSC) have emerged from development stage to early stage of commercialisation over the past 2 years. Rather than using a PN junction, the cell operates by a process designated as artificial photosynthesis. Plants absorb sunlight and through the use of stored chlorophyll the plant produces sufficient energy for its own needs. The DSC cell comprises and outer sheet of glass followed by a layer of titania which is a white pigment, flowed by ruthenium dye santhiched between glass, beneath which there is an electrolyte with a second sheet of glass completing the assembly. Light striking the dye excites electrons which are absorbed by the titania to create an electric current.

Fig 2.7 DSC Source: elp.uji.es The initial problems associated ith the toxicity and containment of the dye and electrolyte are slowly being eliminated by development but some difficulties vvith stability of dyes and electrolyte remain to be solved. It is forecast that the DSC cell will be making a significant contribution to renewable energy generation by 2020.

PV technologies will continue to evolve with the aim of improved efficiencies and cheaper materials and manufacturing costs. The technology covered in this chapter is not exhaustive but is intended to show the types of solar cells currently available and likely to become available or be further developed over the next ten to fifteen years.

CONCLUSIONS

PV technologies will continue to evolve with the aim of improved efficiencies, cheaper materials and manufacturing costs. The technology covered in this chapter is not exhaustive but is intended to document the types of photovoltaic cells currently in commercial production together with those likely to be further developed throughout the next ten to fifteen years.

The innovative BIPV media panel will include leading PV technology and subject to further considerations included in the folloAng chapters, this is likely to comprise thin film and dye sensitised elements.

Quantify the deficiencies limitations and drawbacks of existing PV and Media system

SOLARPRINT

The Solarprint company was formed to research and develop technologies that would convert light from any source internally or externally into harvestable energy.

The Dye-sensitised solar cell (DSSC) is a printable solar cell that is the closest technology to the natural process of photosynthesis where plants convert light into energy. This process is highly cost competitive due to cheap raw materials.

The original application of this technology was envisaged as power for electronic equipment such as computers and mobile phones and for this reason the development has concentrated on harvesting of energy from the internal light spectrum. It was envisaged that equipment batteries, charging facilities and associated equipment could be eliminated accordingly.

DSSC was invented by Michael Grätzel and Brian O'Regan at the École Polytechnique Federale de Lausanne (EPFL) in 1991 and is therefore also known as "Grätzel cells". DSSCs are electrochemical devices comprising a light-absorbing molecule anchored onto semiconducting titanium dioxide (Ti02) nanoparticles, which make use of sunlight to generate electricity.

Fig 3.1.4 Solarprint images Source: Solarprint The DSSC has attracted interest globally. The academic community are interested in the performance efficiency inflation' through modified dyes, more effective materials and additional constituents to the cell.

Although originally developed for the internal light spectrum, the system can be tuned to the actual ambient light spectrum to harvest the maximum available energy.

DSSC has a very high response in the 400-800 nm wavelength range. Lighting from fluorescent and incandescent fittings and LED's is broadly in the 600 nm range and this explains the high power output it has in the visible, indoor light spectrum. DSSC spectrum overlaps and matches with the visible, ambient indoor light.

Fig 3.1.4 Solarprint images Source: Solarprint The above graph shows the difference in efficiencies between Ti02 and Ti02+N719. The latter performs well in ambient florescent internal lighting conditions and has increased sensitivity to visible light between 400 and 750 nanometres compared to a bare Ti02 film.

The indoor performance metric is the power density output (microWatts/cm2) of a cell or module at a particular luminance ("lux") level. The industry standard benchmark that has been adopted is power density at 200 lux. Putting this in context, the typical office lux intensity is between 400-700 lux.

Fig 3.1.4 Solarprint images Source: Solarprint Advantages: Transparent Simple and relatively cheap to manufacture.

Materials readily available.

High performance in low diffused ambient light.

In the future both flexible (metal or plastic) and rigid cell constructions are possible.

Tunable to the available light spectrum.

Very low cost required compared to other PV technologies.

The system can be fully integrated into existing façade systems making refurbishment and installation of one of the above systems possible i.e. fully integrable.

The system can harvest a large portion of the light spectrum.

No visible connectors.

No visible cables, no penetrations to wall (all cables are in space behind the panels).

Good performance under shadowing and high temperatures.

Dra'Macks: Acoustic and thermal performance criteria not available.

Power generation capability in low light conditions not available.

Product lifetime not known.

Product reproducibility may be problematic.

Feasibility of manufacture of large panels not known.

Difficulty of sealing electrolyte in larger assemblies.

Some dyes and electrolytes may be a risk to human health if leakage occurs.

The ability to effectively scale up the concept as the corrosive nature of the iodide/triiodide couple makes the use of metallic bus lines problematic.

The liquid state of the electrolyte makes serial interconnection and long term sealing very challenging.

There is a limitation on the maximum power this system could generate, due to a fundamental loss in energy during the charge generation process.

(Solarprint, ND)

OXFORD PHOTOVOLTAICS

Oxford Photovolatics is a research and development organization that has developed a solid state DSC PV to overcome the deficiencies of the previous developments. The three main areas of concern with the Gratzel cell probably precluding their development into larger panels are the last three items listed in the drawbacks of the panels above The solid state DSC is designed to eliminate all the above restrictions by the use of a solid state redox couple, the energy of which can be more closely matched to the energy of the hole in the dye thus minimising the voltage loss in the dye regeneration process. It is envisaged that further development ill enable larger modules to be constructed which are capable of delivering efficiencies close to those of an ideal DSC.

Advantages Transparent.

Range of colour tints.

Aesthetically attractive.

Simple printing manufacturing.

Non toxic and readily available materials.

High performance in low diffused ambient light.

In the future both flexible (metal or plastic) and rigid cell constructions are possible.

Tuneable to the desired available light.

Very low cost required compared to other PV technologies.

The system can be fully integrated into existing façade systems making refurbishment and installation of one of the above systems possible i.e. fully integrable.

The system can harvest a large portion of the light spectrum.

No visible connectors.

No visible cables, no penetrations to wall (all cables are in space behind the panels).

Good performance under shadowing and high temperatures.

Negatives: Thermal and acoustic performance criteria not available.

Power output particulars in various light conditions not available.

Product lifetime and reliability not yet established.

Product reproducibility.

Feasibility of manufacture of larger panels not yet proven.

(Kevin Arthur 2012) With the incorporation of a Lithium-Manganese Dioxide Cell as a coating, film or printed application the unit could incorporate a battery to store the harvested solar energy.

U.C.L.A POLYMER SOLAR CELL Researchers at University College of Los Angeles (UCLA)are reported to have developed a new transparent solar cell that is an advance toward giving windows in homes and other buildings the ability to generate electricity while still allowing people to see outside.

The UCLA team describes a new kind of polymer solar cell (PSC) that produces energy by absorbing mainly infrared light, not visible light, making the cells nearly 70% transparent to the human eye. They made the device from a photoactive plastic that converts infrared light into an electrical current.

Fig 3.1.6 UCLA PSC image Source: UCLA Whilst the transparency level of this development would provide a major requirement of an innovative BIPV, the technology is at the early stage of development and it is not presently possible to determine the relative advantages and drawbacks at this time (Jennifer Marcus, 21July 2012)

MASSACHUSETTS INSTITUTE OF TECHNOLGY CARBON SOLAR CELL

The most interesting and innovative high performing PV cell is yet to come to market. This system harvests the light spectrum in the near -infrared region. 40% of this light reaches the earth's surface. As this light is in the bn viable spectrum the panel Mll appear almost 95% transparent.

This all-carbon solar cell developed by researchers at the Massachusefts Institute of Technology (MIT) could tap into that unused energy, opening up the possibility of combination or cascade solar cells.

"It's a fundamentally new kind of photovoltaic cell," says Michael Strano, the Charles and Hilda Roddey Professor of Chemical Engineering at MIT and senior author of a paper describing the new device published in the journal Advanced Materials.

The cell is made of two forms of carbon: carbon nanotubes and C60, othenMse known as buckyballs. This is purported to be the first all-carbon photovoltaic cell.

The research is at a preliminary stage and no technical details are yet in the public domain.

(David Chandler, 21st June 2012) (Columbia MD, 1 5th March 2012)

CURRENT STATE OF THE ART MEDIA SYSTEMS

Media facades open up new urban communication possibilities. Buildings with a permanently changing facade take on a character of their own. The relationship between a building and its facade has always posed a great challenge to architects, advertisers and urban planners.

This section will identify and appraise the systems currently in use that may be incorporated into an innovative BIPV building facade.

PRINTED OLED

An OLED is an organic semiconductor made up of two or three layers of organic material.

Fig 3.2.4 OLED Source: electronics. howstuffworks Substrate (clear plastic, glass, foil) -The substrate supports the OLED.

Anode (transparent) -The anode removes electrons (adds electron "holes") when a current flows through the device.

Organic layers -These layers are made of organic molecules or polymers.

Conducting layer -This layer is made of organic plastic molecules that transport "holes" from the anode. One conducting polymer used in OLEDs is polyaniline.

Ernissive layer -This layer is made of organic plastic molecules (different ones from the conducting layer) that transport electrons from the cathode; this is where light is made. One polymer used in the emissive layer is polyfluorene.

Cathode (may or may not be transparent depending on the type of OLED) -The cathode injects electrons when a current flows through the device.

The hardest part of the process is apply the OLED to the substrate normally by one of three methods: Vacuum deposition or vacuum thermal evaporation (VTE) -In a vacuum chamber, the organic molecules are gently heated (evaporated) and allowed to condense as thin films onto cooled substrates. This process is expensive and inefficient.

Organic vapour phase deposition (OVPD) -In a low-pressure, hot-walled reactor chamber! a carrier gas transports evaporated organic molecules onto cooled substrates! where they condense into thin films. Using a carrier gas increases the efficiency and reduces the cost of making OLEDs.

lnkjet printing -With inkjet technology, OLEDs are sprayed onto substrates just like inks are sprayed onto paper during printing. lnkjet technology greatly reduces the cost of OLED manufacturing and allows OLEDs to be printed onto very large films for large displays like 80-inch TV screens or electronic billboards.

(Craig Freudenrich, 2012) How OLEDs emit light OLEDs emit light in a similar manner to LEDs, through a process called electro phosphorescence.

Fig 3.2.4 OLED Source: electronics. howstuffworks The process is as follows: 1. The battery or power supply of the device containing the OLED applies a voltage across the OLED.

2. An electrical current flows from the cathode to the anode through the organic layers (an electrical current is a flow of electrons). The cathode gives electrons to the emissive layer of organic molecules. The anode removes electrons from the conductive layer of organic molecules. (This is the equivalent to giving electron holes to the conductive layer.) 3. At the boundary between the emissive and the conductive layers, electrons find electron holes. When an electron finds an electron hole, the electron fills the hole (it falls into an energy level of the atom that is missing an electron). When this happens, the electron gives up energy in the form of a photon of light.

4. The OLED emits light.

5. The colour of the light depends on the type of organic molecule in the emissive layer.

Manufacturers place several types of organic films on the same OLED to make colour displays.

6. The intensity or brightness of the light depends on the amount of electrical current applied: the more current, the brighter the light (Craig Freudenrich, 2012) Types of OLEDs: Passive and Active Matrix There are several types of OLEDs: * Passive-matrix OLED * Active-matrix OLED * Transparent OLED * Top-emitting OLED * Foldable OLED * White OLED Each type has different uses as indicated in the following section.

Passive-matrix OLED (PMOLED) PMOLEDs have strips of cathode, organic layers and strips of anode. The anode strips are arranged perpendicular to the cathode strips. The intersections of the cathode and anode make up the pixels where light is emitted. External circuitry applies current to selected strips of anode and cathode, determining which pixels get turned on and which pixels remain off. Again, the brightness of each pixel is proportional to the amount of applied current.

Fig 3.2.4 OLED Source: electronics. howstuffworks PMOLEDs are easy to make, but they consume more power than other types of OLED, mainly due to the power needed for the external circuitry. PMOLEDs are most efficient for text and icons and are best suited for small screens (2-to 3-inch diagonal) such as those found in, mobile phones and MP3 players. Even with the external circuitry, passive-matrix OLEDs consume less battery power than the LCDs that currently power these devices.

Active-matrix OLED (AMOLED) AMOLEDs have full layers of cathode, organic molecules and anode, but the anode layer overlays a thin film transistor (TFT) array that forms a matrix. The TFT array itself is the circuitry that determines which pixels get turned on to form an image.

Fig 3.2.4 OLED Source: electronics. howstuffworks AMOLEDs consume less power than FMOLEDs because the TFT array requires less power than external circuitry, so they are efficient for large displays. AMOLEDs also have faster refresh rates suitable for video. The best uses for AMOLEDs are computer monitors, large-screen TVs and electronic signs or billboards.

(Craig Freudenrich, 2012) In the TV market this new OLED technology has taken of and is the next big thing for many of the main industry leaders.

LG, Samsung, Sony, Panasonic, Dupont and many more are adopting this method as it is easier to construct, materials are more readily available and it is cheaper to produce than LCD or Plasma.

Fig 3.2.4a LCD, OLED comparable Source: treehugger

CONCLUSION

Many technologically advanced products currently available in PV and digital media market and that many companies and research organizations are seeking to advance several aspects of knowledge and product performance in a very active development environment.

Using the information above and with particular reference to the advantages and deficiencies of each system identified will facilitate the selection of equipment suitable for inclusion, either in its present form or with modifications, in an innovative BIPV media panel.

In the next chapters suitable systems will be further evaluated and combined with an innovative step into a patentable usable product.

Evaluate the potential for further development and technical feasibility.

Previous chapters indicate the current state of the art in the application of components and assemblies likely to be required for inclusion within an innovative BIPV panel. In order to achieve the desired performance it will be necessary to consider what further development is possible and achievable.

This chapter will indicate particular aspects of development likely to be of use for the purpose intended enabling the most likely components to be combined into an innovative BIPV idea.

PHOTOVOLTAIC CELLS

It is obvious that the PV unit will need to maximize the energy it produces to make the idea as viable as possible. By far the best way of maximizing performance is to include the possibility of harvesting energy from the widest possible range of the light spectrum. The PV unit will therefore need to be constructed as a cascade unit that can harvest infrared, ultraviolet and internal fluorescent light to generate power.

The major disadvantage of this assembly is that the transparency of the composite assembly will be adversely affected which could potentially compromise its use and application as a BIPV curtain wall I DGU.

The cascade PV assembly will be achieved by the use of a combination of different types of PV to optimize the amount of electromagnetic energy harvested.

The illustration below indicates the band gaps that we will endeavour to investigate in the infra red and ultraviolet spectrum.

Fig 4.1.1 Wavelength Source: ChandraSpectrum * Ultraviolet C or(UVC) range, which spans a range of 100 to 280 nm. The term ultra violet refers to the fact that the radiation is at higher frequency than violet light (and, hence also invisible to the human eye). Owing to absorption by the atmosphere very little reaches the Earth's surface. This spectrum of radiation has germicidal properties, and is used in germicidal lamps.

* Ultraviolet B or(UVB) range spans 280 to 315 nm. It is also greatly absorbed by the atmosphere, and along with UVC is responsible for the photochemical reaction leading to the production of the ozone layer.

* Ultraviolet Aoi (UVA) spans 315 to 400 nm. It has been traditionally held as less damaging to DNA and hence used in cosmetic tanning and some medical therapies * Visible range or light spans 380 to 780 nm. As the name suggests, it is this range that is visible to the naked eye.

* Infrared range spans 700 nm to 106 nm). It is responsible for an important part of the electromagnetic radiation that reaches the Earth. It is also divided into three types on the basis of wavelength: o Infrared-A: 700 nm to 1,400 nm o Infrared-B: 1,400 nm to 3,000 nm o Infrared-C: 3,000 nm to 1 mm.

List of band gaps Material Symbol Band gap (eV) @ 302K Silicon Si 1.11 Selenium Se 1.74 Germanium Ge 0.67 Silicon carbide SiC 2.86 Aluminium phosphide AlP 2.45 Aluminium arsenide AlAs 2.16 Aluminium antimonide AlSb 1.6 Aluniinuim nitride AIN 6.3 Carbon C 5.5 Gallium (3) phosphide GaP 2.26 Gallium (3) arsenide GaAs 1.43 Gallium (3) nitride GaN 3.4 Gallium (2) sulphide GaS 2.5 Material Symbol Band gap (eV) @ 302K Gallium antimonide GaSb 0.7 Indium antimonide InSb 0.17 Indium (2) nitride InN 0.7 Indium (3) phosphide InP 1.35 Indium (3) arsenide InAs 0.36 Zinc oxide ZnO 3.37 Zinc sulphide ZnS 3.6 Zinc selenide ZnSe 2.7 Zinc telluride ZnTe 2.25 Cadmium sulphide CdS 2.42 Cadmium selenide CdSe 1.73 Cadmium telluride CdTe 1.49 Lead (2) sulphide PbS 0.37 Lead (2) PbSe 0.27 selenide Lead (2) telluiide PbTe 0.29 Copper (2) oxide CuO 1.2 Copper (1) oxide Cu20 2.1 Iron disilicide â-FeSi2 0.87 Material Symbol EG [eV] Germanium (Ge) 0.67 Crystalline Silicon (c-Si) 1.11 Gallium (3) arsenide (GaAs) 1.42 Cadmium telluride (CdTe) 1.49 Amorphous Silicon (a-Si) 1.70 Gallium (3) phosphide (GaP) 2.26 Cadmium sulphide (CdS) 2.45 Fluorescent light 1.00 (Wikipedia, ND) The elements indicated above will be considered for incorporation into the innovative BIPV unit to maximize the amount of harvested energy.

In order to minimize weight and manufacturing costs whilst achieving maximum transparency and architectural appeal the innovative unit will use thin film technology with transparent conductive films.

The thin film solar cell (TFSC) or thin film photovoltaic cell (TFPV) incorporate transparent conductive films (TCF) that are made by depositing photovoltaic material onto the substrate glass or thin film.

The solar cells used for this innovation will incorporate some or all of the following materials in combination as a cascade solar cell to harvest the maximum amount of solar energy practically possible.

Amorphous silicon (a-Si) Thin-film silicon (TF-Si) Cadmium Telluride (CdTe) Copper Indium Gallium Selenide (CIS or CIGS) Dye Sensitive solar cell (DSC)

ORGANIC SOLAR CELLS

Transparent conducting films can be either inorganic or organic and both are applied to a substrate. The majority of this film cells currently in use incorporate inorganic materials and the application and manufacturing processes are now well developed. The main disadvantage, as indicated in a previous chapter, is loss of transparency particularly when used in a cascade arrangement.

Organic solar cells include carbon nanotube networks graphene which is highly transparent after application. This substrate used is also transparent to act as a window for light to strike the active material beneath. Carrier generation occurs at the ohmic contact for carrier transport out of the photovoltaic but also as a transparent carrier for surface mounted electronics used between either laminated glass or light tranmissive composite materials.

The transparent material collects the light energy in the band gaps required whilst allowing visible light through.

PV ELEMENT OF INNOVATIVE PANEL

Using the table above the materials that will give best performance across the area of the light spectrum of interest can be easily determined. This will enable the innovative unit to harvest energy from the ultra violet, infra red and florescent parts of the natural light spectrum.

Most types of solar panels can be tuned to operate at particular wave lengths but in for reasons indicated above a cascade assembly is practically and technically feasible only if this film technology is used. This is particularly important to maintain transparency.

To harvest energy from the internalfluorescent and infra red band gaps, a selection of amorphous films will be utilised To harvest energy from the infra red band gap, a selection of zinc oxides and aluminium nitrates will be utilised.

Incorporation of a DSSC thin film with the above will enable a very high proportion of the light energy throughout the ultra violet to infra red range! excluding the visible spectrum, to be harvested.

The adoption of the above would also ensure that the composite panel was transparent.

Noting from the above that silicon, which remains relatively cheap and available, and which has been extensively used for first generation solar panels is suitable for the band gap of interest, the possibility of its use in a thin film format has been investigated.

The current industrial production of silicon is via a reaction, known as carbothermic reduction, between carbon and raw silicon at high temperature. Each tonne of 98% pure silicon emits about 1.5 tonnes of carbon dioxide and the process is environmentally harmful.

Raw silica can be directly reduced to pure silicon by electrolysis in a molten salt bath at a temperature of 800 to 900 degrees Centigrade. The environmental and other aspects of the process have not been determined but an interesting laboratory finding is that the electrolytic silicon is in the form of porous silicon which turn readily into a fine powder with a particle size of a few micrometers. This may offer new opportunities for solar cell technology development perhaps as a TCF in a tin film composite cell.

Much further development is needed before to determine the potential for this material and its use in the innovative cell has been discounted for this reason.

BATTERY

The majority of mobile phones, computers and consumer electronics currently available are powered by lithium ion batteries.

Compared to nickel cadmium batteries typically used in cameras, the nickel ion design has twice the energy density, requires no maintenance and its disposal causes very little environmental harm. The technology is subject to rapid and continuous enhancement and no other battery design that affords similar advantages and improvement potential, the innovative BIPV will incorporate electrical storage in the form of a lithium ion battery assembly.

Having given much attention to the transparency of the PV unit, the inclusion of a battery should not interfere with either the transparency or architectural appearance of the final assembly.

Several companies have successfully created partially transparent gadgets such as photo frames and see-through keyboards but none of these have incorporated the battery in the transparent part of the assembly. In 2011 however! it was reported that researchers at Stanford University in California had successfully developed a transparent lithium ion battery, initially for use in consumer electronics.

(Stephanie Liou, 25th July2011) The battery electrodes comprise a mesh like frame work with each "line" in the grid being 35 microns wide. Light passes through the transparent gaps between the grid lines and because the individual lines are thinner than the minimum resolving power of the human eye, the entire network appears transparent.

To ensure cheap manufacture and to ensure transparency, metallic materials could not be considered and a low cost material was needed. A material already in use for plastic surgery and contact lenses called polydimethylsiloxane (PDMS) which is a slightly rubbery transparent stable compound was selected for the application. The material is not conductive so it is poured into silicon moulds to create grid patterned trenches with a metal film being poured over the trenches to create a conductive layer. The trenches are then filled with a liquid slurry solution containing miniscule nano sized active electrode materials An existing gel electrolyte was modified to act as both an electrolyte and a separator and by placing this between two electrodes, a functional transparent battery is created. Multi layers can be added to create a larger and more powerful battery.

It is believed that the energy density and scaling of the battery has been improved since the above report and it is intended that the innovative panel will incorporate a transparent nickel ion battery.

OLED technology as explained in chapter 3 will be included as the media element of the innovative panel.

In the OLED assembly, electrons flow from the cathode to the anode through the conductive organic layer. The remaining electrons from the conductive layer leave holes that are filled with electrons from the emissive layer. The holes jump to the emissive layer and join with electrons which drop into the holes and release light. Dependent on the organic material used this light is either red green or blue. These pixel colours in turn create the RGB screen resulting in the appearance of a digital televisual image.

It is planned that the make up in the unit will comprise of a square of four equal parts that are segmented into red, green, blue and clear pixels.

The following table shows the organic material (Fluorophores) to be used to achieve the desired colours:

FLUOROPHORE TABLE

Dye Absorbance Wavelength Emission Wavelength Visible colour Hydroxycoumarin 325 386 blue methoxycoumarin 360 410 blue Alexa fluor 345 442 blue aminocoumarin 350 445 blue Cy2 490 510 green (dark) FAM 495 516 green (dark) Alexa fluoi 488 517 green (light) Fluorescein FITC 495 518 green (light) Alexa fluor 430 545 green (light) Alexa fluoi 532 555 green (light) HEX 535 556 green (light) Cy3 550 570 yellow TRITC 547 572 yellow Alexa fluoi 546 573 yellow Alexa fluor 555 573 yellow R-phycoerythrin (PE) 480 578 yellow Rhodamine Red-X 560 580 oiange Tamara 565 580 red Cy3.5 581 596 red Rox 575 602 ied Alexa fluor 568 603 red Red 480 613 red Texas Red 615 615 ied Alexa fluor 594 617 red Alexa fluor 633 639 red Allophycocyanin 650 660 ied Alexa fluoi 633 668 ied Cy5 650 670 red Alexa fluoi 660 690 ied Cy5.5 675 694 red TruRed 675 695 red Alexa fluoi 680 702 ied Cy7 743 770 red Nucleic acid probes: Dye Absorbance Wavelength Emission Wavelength Visible colour DAPI 345 455 blue Hoechst 33258 345 478 blue SYTOX blue 431 480 blue Hoechst 33342 343 483 blue YOYO-1 509 509 green SYTOX green 504 533 green TOTO 1, TO-PRO-i 509 533 green SYTOX orange 547 570 yellow Chromoniycin A3 445 575 yellow Mithramycin 445 575 yellow Propidium iodide 536 617 red Ethidium bromide 493 620 red (Abcam, ND)

OTHER REQUIREMENTS

Facade systems The innovative assembly will be designed and constructed for use with all standard curtain walling systems including stick system, unitized, panelised, cassette panels, spandrel panels, structural sealant glazing, structural glazing, rain screen and cladding. The design will comply with the latest regulations with regard to thermal and acoustic performance etc. It is intended that the assembly will be suitable for use with all common fixing and sealant systems to enable the retrofitting of the majority of existing facades.

Unit types The unit will be either a double or triple glazed unit. It will comprise of two or three transparent panels which will consist of a cascade PV, one OLED screen. The unit will have an air gap which can be gas filled for extra thermal performance. The unit will be dual sealed and desiccant filled to stop and condensation or misting.

The Innovative Assembly Configuring these elements and layering them in a unique way will create a new and innovative product that can achieve the following.

The transparent unit can achieve all aspects of a regular double or triple glazed window, transparency view, weather tightness, thermal barrier, U values, low Emissivity, solar shading, impact resistant barrier and conform to all the relevant BS EN and building regulations.

In addition to these it will generate its own power through transparent solar thin film technology and have the ability to store energy in its thin film lithium battery. Any additional power can be utilised in the rest of the building or sold back to the grid. The unit will display televisual images.

Fig 5 shows the layered innovation Fig 5A Self cleaning titanium oxide layer and anti reflective layer.

Fig 5B Single sheet glass, toughened or laminated or other transparent substrate plastics.

Fig 5C Dual edge seal to prevent any moisture ingress and condensation.

Fig 5D Desiccant edge spacer to dry any condensation.

Fig 5E PV panels to capture sun light and ambient light to form a cascade PV cell system.

With the addition of a lithium transparent thin film battery.

Fig 5F OLED screen with reflective and prismatic lens films to reflect, direct and polarize natural and ambient light back through the panel.

Fig 5G the cavity is air, gas or gel filled for optimum thermal performance.

Fig 5H low emissivity coating to trap long wave ambient light and heat and additionally feed the rear PV cell.

Layering of components could be rearranged to optimise performance after testing of prototype assembly.

CONCLUSIONS

The information obtained during the research of details contained in this chapter has confirmed that the technology and elements that are essential for the feasibility, practicality and performance of the innovative BIPV panel are available. Equally importantly, the performance parameters can be assessed and compared with the required essential criteria enabling the identification of necessary improvements and modifications.

This aspect is further explored and amplified below.

Identify key performance criteria that need to be considered.

This innovative BIPV media unit will be designed and constructed as a standalone system for new and retrofit applications and as such it must comply with many requirements and regulations. This chapter considers how compliance with these criteria will be accommodated and ensured.

PHOTO VOLATICS

In order to be environmentally friendly and to comply with the current building energy requirements and aspirations the innovative unit will generate its own energy through photovoltaic effect as explained in depth in the previous chapters.

From the process explained in previous chapters, electrical energy in excess of the power required for media will be available at most times of the year. This power can be fed back into the unit to charge the battery with any further excess being fed into the national grid at feed in tariff rates to reduce whole building running costs.

A key requirement of the assembly is that the maximum amount of available energy should be harvested from the light spectrum both internal and external. The design will include a cascade using various organic materials based upon the theoretical information currently available. This would need to be tested and verified using a prototype assembly in a range of performance conditions to identify the best specific combination of materials to achieve this most important requirement. Manufacture of the prototype and verification testing is outside the scope of this dissertation.

MEDIA ELEMENT: For the reasons stated in the previous chapter, the media element of this unit will be achieved using OLED technology where the electron exchange through the organic material releases photons (visible light) through a specific organic material that produced red, green or blue illumination. The RGB pixel combination from a distance will form televisual moving images.

This process will be powered by the PV, the battery and recycled light emifted from the media screen itself.

The major criteria for the media is that * Both two dimensional and three dimensional still and moving images must be possible * The images must be clear and sharp.

* The façade must be transparent when the media is not in use.

* The image can be viewed from the outside of the façade only * The overall effect must be pleasing to the eye * The appearance must be architecturally pleasant There is good reason to believe that OLED technology, properly applied, will achieve the above criteria.

BATTERY

It has been stated in a previous chapter that a lithium ion battery assembly will be used for the storage of electrical energy in the innovative panel. This type of battery will best meet the following important criteria for this crucial component * Small size and particularly thin * Least weight * High energy density * Long life and good reliability * Low, preferably zero, maintenance * Environmentally friendly especially on disposal * Relatively cheap to manufacture U Transparent * Capable of improvement by further development * Readily commercially available * Available in different shapes to suit application U Suitable for parallel use to increase capacity The transparent lithium ion battery described in the previous chapter appears to be the only option that adequately fulfils all of the above criteria. Use of any other battery will require compromise of one or more of these parameters

ELECTRICAL CIRCUIT AND COMPONENTS

Whilst it is planned that the innovative panel will be designed and constructed to include the layered film materials, substrates, battery, electrical connections and OLED media element all within a single sealed and weatherproofed frame, the fact that electrical energy will be available for transfer for use elsewhere in the building and/or the national grid, requires that additional electrical equipment and wiring will be required.

This is not part of the development of the BI FV panel but connections will be provided to enable the export of energy from any number of panels grouped together in a façade structure.

The diagram below shows a typical arrangement of the external kit likely to be required for the above purpose. Any energy produced which is not used for media or charging of the internal panel battery will be routed from each panel via cables hidden in the façade support structure to a combiner box and thence via, as a minimum, an inverter to change the direct current to alternating current.

It is envisaged that the operating system for the media element would be hard wired with the cables hidden in the façade structure.

The system will incorporate a memory card, blue tooth and wireless connections together with an encoder and decoder programmed to read a series of binary signals enabling the desired image to be displayed.

Because the BIPV panel is intended for worldwide operation, it will be necessary for the operating system to be compatible with the four major digital television terrestrial broadcasting (DTTB) standards, which are: Advanced Television System Committee (ATSC) -this has been adopted in USA and several other countries Digital Video Broadcasting -Terrestrial (DVB-T) -this has been adopted in Europe Terrestrial Integrated Services Digital Broadcasting (DTMB) -this has been adopted in Japan Digital Terrestrial Multi Media Broadcasting -(DTMB) -this has been adopted in China and other countries in the Far East.

(Wikipedia, ND)

OTHER IMPORTANT PERFORMACE CRITERIA

Weather tightness: The assembly will be sealed and made weather tight in accordance with current requirements and will be immune to the environment as an assembly. The weather tightness of the façade, particularly in ietrofit applications will depend upon the façade sealing system used.

Thermal performance: The unit will have black nylon glazing bars tilled with desiccant and dual sealed. The unit will be gas filled with Argon or similar. The nylon glazing bars will prevent conduction edge effect and prevent over cooling or heating. The desiccant will remove any moisture in the unit. The dual seal will seal the unit and stop any moisture entering the unit. The gas within the unit will increase the thermal efficiency.

With the incorporation of a Low E glass the heat will be retained within the room during winter months. However if this has an impact on the amount of long wave radiation harvested it may be omitted in the interest of energy performance.

Solar control: Dependent on the use of the building the design of the assembly will allow foi solar control oxides to be incorporated to reduce glaie and distiaction when the media panel is active to the occupants internally.

Loadings: The panel conforms to the lequirements for glazing as detailed below dependent on the specific requirements of the project. The specification Mll change dependent on the client's needs: BS 6206: 1981 Specification for impact performance requirements for flat safety glass and safety plastics for use in buildings BS 6262: 1982 Code of practice for glazings for buildings Part 4: 2005 Safety relating to human impact BS 6180: 1999 Code of practice -Barriers in and about buildings BS 5516: 2004 Code of practice for design and installation of sloping and vertical patent glazing BS EN 1063: 2000 Glass in building. Security glazing.

Testing and classification of resistance against bullet attack BS 5357: 1995 Code of practice for installation and security glazing BS EN 356: 2000 Glass in building. Security glazing.

Testing and classification of resistance against manual attack BS EN 13541:2000 Glass in building. Security glazing.

Testing and classification of resistance against explosion pressure BS 6399 Loading for buildings Part 1: 1996 Code of practice for dead and imposed loads Part 2: 1997 Code of practice for wind-loads Part 3:1988 Code of practice for imposed root loads BS 7376: 2004 Specification for inclusion of glass in the construction of tables or trolleys BS 7449: 1991 Specification for inclusion of glass in the construction of furniture, other than tables or trolleys, including cabinets, shelving systems and wall-hung or free-standing mirrors BS 8213: 2004 Part 1: Windows, doors and rooflights Code of practice for safety in use and during cleaning of windows and doors BS EN 12150 Glass in building. Thermally toughened soda lime silicate safety glass

Part 1: 2000 Definition and description

Part 2: 2004 Evaluation of conformity/Product standard BS EN 12600: 2002 Glass in building. Pendulum test.

Impact test method and classification for flat glass BS EN ISO 12543: 1998 Glass in building. Laminated glass and laminated safety glass BS EN 1863 Glass in buildings. Heat strengthened soda lime silicate glass

Part 1: 2000 Definition and description

Part 2: 2004 Evaluation of conformity. Product standard BS EN 14179: 2005 Glass in building. Heat-soaked thermally-toughened soda lime silicate safety glass BS EN 14449: 2005 Glass in building. Laminated glass and laminated safety glass Evaluation of conformity/product standard BS 8000 Workmanship on building sites Par 7:1990 Code of Practice for glazing BS EN 14072:2003 Glass in furniture. Test methods Workplace Regulation 14 Windows, transparent or truslucent doors, gates and walls Safety, security, design and installation (Health & Safety and Welfare) Regulation (1992) The Building Regulations Part A: 2004 Structure Part B: 2002 Fire safety Part E: 2003 Resistance to the passage of sound Part F: 2006 Ventilation Part K: 1998 Protection from falling collision and impact Part Li: 2006 Conservation of fuel and power: Dwellings Part L2: 2006 Conservation of fuel and power: Buildings other than dwellings Part N: 1998 Glazing The Building (Scotland) Section 0 -General Section 1 -Structure Section 2 -Fire Section 3-Environment Section 4 -Safety Section 5-Noise Section 6 -Energy The Building Regulations Part D: Structure Part E: Fire safety Part F: Conservation of fuel and power Part G: Sound insulation of dwellings Part H: Stairs, ramps, guarding and protection from impact Park K: Ventilation PartV: Glazing It is the responsibility of the purchaser or specifier to ensure that the product ordered is appropriate to its application and that its use complies with all local and national legislation, Building Regulations, standards, codes of practice and any other requirement.

BS EN 1096 Part 1: 1999 Definitions and classification Part 2: 2001 Requirements and tests method for class A, B and S coatings Part 3: 2001 Requirements and test methods for class C and D coatings Part 4: 2004 Evaluation of conformity/Product standard BS EN 12898: 2001 Glass in building, determination of the emissivity BS EN 1279 Part 1:2004 Generalities and dimensional tolerances Part 2: 2002 Long-term test method and requirements on moisture vapour penetration Part 3: 2002 Initial type testing on gas-filled insulating glass units: gas concentration and gas leakage rate Part 4: 2002 Methods of test for the physical attributes of edge seals Part 5: 2005 Evaluation of conformity/Product standard Part 6: 2002 Factory production control BS EN 410: 1998 Glass in building. Determination of luminous and solar characteristics of glazing BS EN 673: 1998 Glass in building.

Determination of thermal transmiftance (value). Calculation method BS EN ISO 12567 Part 1:2000 Thermal performance of windows and doors.

Determination of thermal transmittance by hot box method.

Complete windows and doors.

Part 2: 2005 Thermal performance of windows and doors.

Determination of thermal transmittance by hot box method. Roof windows and other projecting windows B5 EN ISO 14438: 2002 Glass in building. Determination of energy balance value.

Calculation method (St Gobain, 2012) Interface with Façade envelope: The unit is designed to be a BIPV panel that can be incorporated into any facade, curtain walling systems including stick system, unitized, panelised, cassette panels, spandrel panels, structural sealant glazing, structural glazing, rain screen and cladding.

The panel will be made available in a reasonable number and variety of shapes shape and practical sizes. For example, the assembly would be fitted in the stick system (i.e. Schuco FW6O) into the glazing rebate on packers. Any UF Cabling could be threaded through the mullion bars and be kept out of sight. The pressure plate and gaskets could then be fitted and tightened to the required torque with the cover plates then fitted for the finished installed article. Other system installation requirements would be incorporated.

Descd ption: BIPV panel prototype construction elements As previously discussed in the earlier chapters the invention is designed to maximise the potential of the large expanse of modern facade curtain walling that at present only operates as a window and weather barrier. At present they don't generate their own power or display televisual media.

The invention will have all the benefits of working as a window, view, weather tightness, thermal barrier, U values, low Emissivity, solar shading, impact resistant barrier and conform to all the relevant BS EN and building regulations. In addition to these it will generate its own power through transparent PV technology and have the ability to store energy through the incorporation of a lithium oxide coated layer. Any addition power can be utilised in the rest of the building or sold back to the grid. The unit will display televisual images as required and can generate and income subsidy from advertising.

The BIPV panel will have the following attributes: * Self cleaning titanium oxide layer and anti reflective layer.

* Transparent laminate / DGUsubstrate.

* Printed OLED screen and decoder (edge deletion for unit make up) * Dual edge seal and black nylon glazing bar with desiccant to prevent any moisture ingress and condensation.

* PV Amorphous, zinc oxides, aluminium nitrates and DSSC layered coatings to capture sun light and ambient light to form a cascade solar cell. With the addition of a lithium oxide coating to form a battery to store the surplus energy.

U Low emissivity coating to trap long wave ambient heat.

The layering of the components will be via the deposition of a microscopic layer of oxide ink jet printed to the surface of the substrate with the relevant anode and cathode conductors.

As outlined in detail in the previous chapters the make up of the unit based on the basic model will be as follows: Ref Fig 1 DRG 1 Fig 1 Self clean Titanium oxide Fig 2 Anti reflective Fig 3 Glass (Transparent Substrate) Fig 4 Cathode -TCO titanium oxide! Aluminium Nitrate Fig 5 AMOLED polyflorecants Fig 6 TFT Matrix Fig 7 a-Si Fig 8 DCCS Fig 9 Lithium battery Fig 10 YSZ Solide state electrolyte Fig 11 Anode + Doped Graphite Fig 12 Dual seal Argon gas filled black nylon edge spacer desiccant Fig 13 Solar control film Glare Fig 14 LowE Fig 15 Glass Fig 16 Anti reflective Please view sketch outlined to show how the unit will work Ref Fig 1 DRG 1.

Develop basic design and sketches suitable for patent application.

The working sketch utilizes the printed Active matrix OLED for the media element. The power is generated by PV in the form of Amorphous Silicon and Dye sensitive cell.

By combining the above cell's it has been possible to cover a larger band gap and therefore harvest more light energy whilst achieving high visibility through the unit. This combination includes the OLED layer in the makeup.

The unit will have reduced cost of manufacture as less material has to be used.

The layering below can be further developed to be applied to a vinyl or similar transparent substrate. This would dramatically lower costs further and enable retro fitting of the PV OLED film to existing window units with adhesive vinyl.

Next generation: The system could be developed further to print layers Fig 4 through to Fig 11 which form the circuit onto another transparent substrate i.e. vinyl. This would lower costs and enable the system to be applied to existing windows or smooth bondable substrates.

VINYL

Vinyl is the most versatile plastic material readily available on the market today. Depending upon the ingredients mixed with the vinyl resin during manufacture, a compound is formed that is rigid or flexible, clear or colourful, thick or thin.

Vinyl products are well known for durability, resistance to corrosion, thermal efficiency, colour retention, ease of cleaning, safety and being environmentally friendly.

There are many products, typically stickers and signs, that are successfully produced by use of an inkjet printer directly onto the vinyl surface. Most ink colours such as red, green and blue are not opaque enough for use on clear vinyl and it is usual for a white ink base to be printed underneath to enable the colours to be seen. This affects the transparency of the vinyl.

The durability, transparency and cost of thin sheet vinyl make it a very good option for inclusion in the innovative BI PV panel. The limitation of colour visibility indicated above is not considered to be a draNback because it is intended to use the vinyl as a substrate for a transparent dye sensitised compound that will be applied using inkjet technology.

Claims (22)

1. Claims: 1. The unit can display colour televisual animated displays, graphics, advertising and change the appearance of the building.
2. 2. The digital televisual display means that the unit can display on a large or small scale to the full width and height of the building.
3. 3. All units can be individually operated to form part of a larger picture, graphic or film.
4. 4. The units can be tiled to form a larger image.
5. 5. The facade its self can change to imitate other building styles, i.e. a gothic cathedral, a Georgian Terrace or a garden any desired effect.
6. 6. The unit can mimic finishes i.e. brick, stone, water, sky, woodland, colours or anything that can be displayed on a conventional television.
7. 7. The design software and control board can relay individual graphics film or data to each panel to work independently or as part of a whole.
8. 8. The unit can be integrated into the facade, cladding or substrate it is attached too.
9. 9. The layering of the panels means other transparent and transparent textured materials can be used.
10. 10. The units can be any shape to accommodate the complex geometry of shaped buildings like the Gherkin, for example.
11. 11. The PV element Mll power the unit
12. 12. It will provide power or partial power to the building or facility it is installed to.
13. 13. The unit is PV powered and can charge its own transparent lithium battery
14. 14. It will, after development provide power that can be sold back to the grid on the FITS Feed in Tariff scheme.
15. 15. Excess energy if not used to recharge the batteries, power the unit or the building can be sold to the grid.
16. 16. The unit will provide thermal performance and required U values
17. 17. The unit will provide the required acoustic performance
18. 18. The unit will provide the required break test and impact performance.
19. 19. The unit will self clean
20. 20. The unit will have a Low E coating
21. 21. This technology can be used for all facades, cladding, and hoardings.
22. 22. With development the principle design can be used for phones, computers, fabrics, clothing and any other product that could be animated and self powered.