AU2020100634A4 - Building integrated photovoltaic thermal panels with structural endurance and enhanced sustainability - Google Patents

Abstract

Abstract: This patent is for BIPVT-330 that is a novel building integrated roof solar panel made of fully recycled materials with an enhanced structural performance and high electrical and thermal power efficiencies. Having architectural appeal and superior structural performance than today's systems, the patented roofing technology will integrate half-cell photovoltaic panels, a heat exchanger and a durable geopolymer composite embedded with corrosion resistant reinforcement. This multi-layered roofing technology will feature free clean electricity and thermal energy, high strength, lightweight material, modularity and seamless integration with building roof profiles. Australia is expected to generate 80% of its energy from renewable sources by 2030. Currently 71.1% of all its dwellings are separate houses, but only 20% are equipped with solar panels. This limited uptake is partially explained by low efficiency due to poor design and the structurally passive nature of today's panels. In spite of the technology revolution that took place in this sector, implementing innovative cost-effective techniques into this asset classhas not been fully explored yet. This patent is aimed at developing a new roofing technology that offers several functionalities including aesthetic appeal, structural support, free solar energy and water heating. The proposed system is seamlessly integrated, self-supported and it uses a durable geopolymer composite made of recycled industrial waste. By empowering self sufficient and true net zero energy buildings that cannot be achieved with today's solar systems, this novel roofing technology has economic, environmental and social benefits to society and the construction industry in Australia and the rest of the world in general.

Description

1.1 PATENT TITLE

2020100634 26 May 2020

Seamlessly integrated photovoltaic thermal panels with structural endurance and enhanced sustainability

1.2 PATENT QUALITY AND INNOVATION

Global concerns for greenhouse emissions have urged engineers and scientists to replace conventional fossil fuel-based power plants with renewable clean energy generation. While researchers have tackled this issue from the electrical engineering angle, not much attention has been dedicated to innovative multidisciplinary-based sustainable solutions. Anticipating the future needs for smart green buildings, this patent aims at developing building integrated photovoltaic thermal (BIPVT) panels, as shown in Fig. 1(a). This new concept in architectural and structural element design is presented using an innovative construction material geopolymer to facilitate the integration of a photovoltaic panel and a heat exchanger into roofing structures. The proposed seamlessly integrated structural elements can be used in new and existing buildings and will pave the way to a breakthrough in the utilisation of renewable energy in the built environment. The current residential house roofing structural elements have a single function as they are designed solely for load-bearing purpose and are made of either clay, cement tiles or metal cladding. The current industry practice to install conventional rooftop photovoltaic (PV) panels relies on constructing separate metal racks and brackets to support such panels because they are not strong enough to resist their own weight and harsh environmental conditions including wind gust and snow accumulation. Therefore, conventional solar panels in their present form can not replace roof tiles/cladding. On the other hand, the proposed cost-effective hybrid BIPVT panels will not only act as aesthetically appealing structural elements replacing roof tiles/cladding but will also provide clean electrical and thermal energies for future sustainable houses. The detailed five objectives of this patent are to:

• Develop a flowable lightweight sustainable geopolymer composite with mechanical properties that are suitable for house roofing, integrated solar cells and internal heat exchanger water piping system.

•Conduct a series of laboratory structural tests on BIPVT panels with fibre reinforced polymer (FRP) mesh, which will include axial compression, axial tension, shear, flexural loading and combinations thereof to emulate harsh operating and environmental conditions. Then, formulate numerical models to optimise the proposed design and predict the structural stability of the proposed composite BIPVT panel (Fig. la).

•Conduct a series of mechanical and electrical performance tests to validate the robustness of the BIPVT components including the water heating system and the higher yield of the PV modules due to better cooling.

• Develop a reliable monitoring technique to detect incipient faults within the BIPVT panels in real time along with a technique to estimate the PV generated power during cloudy events for optimum utilisation of energy storage batteries.

• Construct a 70 m2 testing facility to examine the performance of the proposed seamlessly integrated roofing system using an array of 20 BIPVT panels (Fig. lb).

The proposed architecturally and structurally integrated panel requires the assemblage of multilayered materials with different properties in order to achieve self-sufficient energy buildings, which cannot be safely, economically or even ecologically achieved with conventional solar panels shown in Fig. 2(a). The proposed BIPVT-330 Watt hybrid panel is 2000 mm long, 1000 mm wide and 35 mm thick. It will be made of a 10 mm geopolymer layer, 5 mm FRP mesh layer, 10 mm heat exchanger

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2020100634 26 May 2020 isolated Aluminium piping, 5 mm thick insulation layer and a 5 mm half-cell mono crystal photovoltaic layer including protective glass surfacing and adhesive. The geopolymer, insulation and isolation materials are all made of lightweight recycled industrial wastes. The proposed BIPVT panel has the advantages of being: seamlessly integrated with the roof profile; self-supported directly on the timber frame and not requiring any roof tiles, cladding, purlins, metal racks or brackets; strong enough to suit sustainable houses in cyclonic regions in Australia; provided with embedded metal pipes to heat up its internal circulated water to provide free thermal energy and at the same time cool down the PV laminate, thereby increasing the conversion efficiency and reducing the temperature inside the house; a safeguard against snow and ice accumulation; and architecturally appealing because it has a slim profile so it can be seamlessly integrated in any roof design. The innovations of the patent include:

• Developing a geopolymer of zero-cement composite fully made from recycled industrial waste such as fly ash, slag, and micro silica. This new composite is sustainable and has a little carbon footprint and exceptional heat resistance.

• Unlike traditional solar panels that require roof tiles/cladding and support racks [1], the BIPVT panel does not require roof tiles, cladding, purlins, or metal brackets where it is directly supported on the timber frame. Thus, it is much more cost effective and aesthetically appealing since the panel is seamlessly integrated in the roof profile.

• Unlike traditional solar panels that can experience short circuits and cause fires as shown in Fig. 2(b), the proposed BIPVT panel does not comprise any exposed external metal cladding or brackets and it has a less fire hazard because of the integrated cooling system. Also, geopolymer has exceptional fire resistance compared to today's rooftiles.

• On the contrary of Tesla roof tiles that require extensive roofing support as shown in Fig. 2(c), the proposed BIPVT hybrid panel is self-supporting and for about one-third of the cost of Tesla roofing technology.

• Unlike the recent PV/thermal panel made from unsustainable complex and thus expensive ($3.67/Watt) functionally degraded materials proposed in [2], the proposed BIPVT panel construction is simple and it is made of recycled industrial waste materials, hence it is a cost effective solution ($1.21/W).

•The proposed BIPVT panels are expected to revolutionise the construction industry by providing multi-functional properties including roofing, generation of clean energy at higher efficiency than the conventional PVs and providing free thermal energy for residential hot water systems.

1.2.1 Motivation:

Currently, there are many options for solar power generation on a building rooftop such as traditional PV panels, transparent glass roof panels, Tesla roof tiles, flexible solar panels, concentrated solar panels and more recently building integrated PV panels [1-3], The most common 4 options are discussed in the following: (1) Traditional 330-Watt PV solar panels, shown in Fig. 2(a), are not selfsupported and are solely used for solar power generation with an average cost of around $330/panel (each panel 2m2), which corresponds to $1/W (www.alibaba.com); (2) Tesla rooftiles, shown in Fig. 2(c), are small panels (~300mrnx~500rnm) that can not be directly installed on the timber frame and require extensive roof purlins. The other drawbacks of this new technology are: (a) High cost, ~$3.5/\N in average; (b) Water ingress: The relatively small solar tile roof exhibits many joints and gaps; (c) Lock in: Once a specific type of solar tile is installed, it is locked in and any upgrade, extension or repair has to use the same type; (d) Efficiency and yield: Owing to the wasted space between the small tiles, the

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2020100634 26 May 2020

PV yield is low; (3) Flexible solar panels: The panel is made of two parts, top rubber laminate glued to bottom metal cladding sheet. This is similar to conventional PV, but the panel is not a standalone, fully integrated or self-supported because it still relies on conventional metal cladding support. Because of the integrated sheet metal, it can potentially exhibit short circuit faults (Fig. 2b). The panel cost can vary but is (4) Concentrated Solar Panel (CSP): Although CSP maximum efficiency is about

1.5 times the efficiency of traditional PV panels, it is not self-supported and its control system is complex. The CSP is composed of four main parts including Fresnel lenses, electro-motor, inverter and a base plate with a cost of ~$2.5/\N, which is 2.5 times the cost of a traditional PV panel. The proposed BIPVT hybrid panel shown in Fig 1(a) is aimed at overcoming the above shortcomings in today's panels.

The proposed BIVT-330 Watt panel comprises the following advantages: (a) Cost-effective solution: Section E2.3 of the Patent Cost shows the estimated cost of the proposed BIPVT 330-Watt panel is $400. This is equivalent to $1.21/W, which is 21.2% higher than the cost of the conventional PV panel, ~30% the cost of the Tesla roof tile, and ~ 50% the cost of CSP. The BIPVT panels are self-supporting and will be used directly for roofing, which will not only save material cost including roof tiles, purlins, cladding, and racking but will also save significant labour cost; (b) Water- tight: Where joints are much less than Tesla roof tiles because the proposed panel is much larger and will be designed with watertight joints; (c) High Efficiency: The whole surface of the panel is operative with no metal edges and also the whole roof is effective, hence increasing the gain. The proposed lightweight (40 kg) selfsupported BIPVT hybrid panel shown in Fig. 1(a) will be installed directly on the timber frame (no roof purlins or metal racks). The BIPVT panel is made of two main components joined (laminated) together using adhesive bonding. The structural component comprises two layers; lightweight geopolymer and thin FRP reinforcement mesh. The structural component will be designed to resist all expected loads including the self-weight of the panel, live load during construction, wind load in cyclonic and noncyclonic regions and snow accumulation. This makes the proposed BIPVT panel suitable for installation in various locations from mild to severe environmental conditions. The embedded heat exchanger (HE) layer is aimed at performing two tasks; transferring thermal energy to the circulated water and reducing the temperature of the PV laminate to increase its generation efficiency. The photovoltaic layer will be fully bonded to the HE flat piping for efficient heat transfer from the PV laminate. The HE Aluminium piping is expected to have a dimension of 10 mm x 30 mm laminated to a half-cell mono crystal PV layer using thermal conductive adhesive. A thin isolation soft layer around the HE and a thin insulation layer are required to maintain the heat in the HE and to preserve the BIPVT panel surface at safe and comfortable temperatures for the building occupants (Fig. lb).

The new 60 or 72 mono crystal half-cell panels will be used in the construction of the BIPVT panel. The half-cell technology provides a higher output power and is usually more reliable than traditional fullcell panels. The proposed system shown in Fig. 1(b) will include an electric pump, a radiant floor heating unit (RFHU), a fully insulated hot water storage tank and an energy storage unit (lithium battery for example), control valves and sensors and an AC/DC inverter. The electric pump is to circulate water during charging and discharging phases, and the inverter is to convert the solar direct current to an alternating current as per conventional solar systems. The control valves are to control the charge/discharge cycles. In the charging phase (6.00 am to 6.00 pm); first the BIPVT panels harvest the solar irradiance into two components. The first one is converted to electricity that can be used for various domestic applications while excess power can be stored in the battery. The second component heats up the water inside the HE. Hot water can be used for different applications including swimming pools and to heat up the floor in winter using the RFHU (Fig. lb). In the discharge phase (6.00 pm to 6.00 am), energy stored in the battery and the hot water stored in the insulated tank will be used during night time by the building occupants. Thus, the proposed system can facilitate self-sufficient and true net zero energy houses especially in remote areas.

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1.2.2 Approach and Methodology:

This proposal involves five tasks meeting the five objectives discussed in Section DI.2 with an estimated period for execution of 3 years as shown in Fig. 3. These tasks are elaborated below.

Task 1: Developing and testing lightweight geopolymer mix

The production of conventional cement is associated with the emission of significant greenhouse gases including methane, nitrous oxide and carbon dioxide into the atmosphere, which represents a safety/health hazard and a significant threat to the environment. Geopolymer is a modern cementitious material, which is made of industrial by- products and possesses excellent durability, fire resistance and thermal properties. The proposed geopolymer mix will be optimised to have a good workability, adequate strength, great durability and fire resistance. The mix will include lightweight sand, fly ash, slag, micro silica and hollow glass microspheres. A mixture of sodium hydroxide and sodium silicate with a modulus Ms = SiO2/Na2O = 1.0 at a dosage of Na2O= 6% will be used as an activator to improve the durability and thermal stability of the composite. Thirty trial mixes will be conducted with different types of FRP meshes. There are commercially available different types of FRP meshes such as glass fibre, aramid and carbon fibres and different adhesives such as epoxy, polyester, vinyl ester and polyurethane resins [11], The use of short synthetic polyvinyl alcohol (PVA) and Polyethylene (PE) fibres will be investigated as an attempt to eliminate the use of the FRP mesh. Durability tests will be performed including water absorption, permeability, chloride ingress and sulphate penetration. As shown in Fig. 4(a), the compressive strength of the solar cured geopolymer composite is more than 90 MPa (black line) while it is more than 70 MPa for the moist cured (red line) geopolymer composite at 28 days. The inset of Fig 4(a) shows the geopolymer test cylinder before and after testing. Fig. 4(b) shows the XRD test results for the recycled industrial wastes, i.e., the fly ash and slag used to produce the solar cured geopolymer. Based on the analysis of nearly 100 mixes in the literature, Cl-Elchalakani [5-6] validated a satisfactory correlation between the geopolymer strength factor (G) and the 28-day compressive strength for both mortar and concrete (Fig. 4c). The G factor is the product of the hydration modulus of the binder, the multiplicative inverse of the w/b ratio (l/(w/b)) and the weight ratio of sodium silicate solids to sodium hydroxide solids (Na2SiO3/NaOH). This developed correlation will be used as a guide to determine the critical variables in the mix design for the geopolymer. Both Cl-Elchalakani and Cl-Karrech have experience in developing geopolymer materials, which will be instrumental to this task [5-10], The design service life of BIPVT panel is 50 years with one charging/discharging cycle per day, which is conservatively equivalent to about 20,000 thermal cycles. Geopolymer composite blocks 100x100x300 mm3 will be tested under cyclic thermal fatigue at 3 different temperatures of 20°C, 40°C and 85°C up to 20,000 cycles. In the past, experimental testing showed that geopolymer has exceptional heat and fire resistance [4],

Task 2: Structural testing of BIPVT Panel and Numerical modelling

A series of experimental tests will be conducted on the developed full-scale BIPVT panel reinforced with FRP mesh under tension, flexure, shear (Figs. 5a, b), compression (Fig. 5c), combined axial-flexure and torsion. The results of the direct compression tests will be incorporated in the numerical models to predict the structural stability and failure modes of the BIPVT panels. Additionally, the effective stress-strain measurements will be used to calibrate the models and ensure that the numerical and experimental approaches are comparable. Previous experimental tests revealed that the failure mechanism (mesh rupture versus mesh debonding) is strongly influenced by the stiffness and aperture opening of the mesh [11], This phenomenon will be examined in the current research by performing

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2020100634 26 May 2020 bond tests to examine the bond between the FRP mesh and the geopolymer. The possibility of using metallic flat piping (HE) as reinforcement to replace the FRP mesh will be also examined. This will save the material and labour cost of the FRP mesh. Numerical modelling is aimed at providing a robust design for the BIPVT panel to avoid premature failure due to local buckling because of the high widthto-thickness ratio. Different panel length-to-width ratios (L/b=1.5, 2.0) will be examined to fully determine its structural stability. A thin-walled panel can fail by a roof mechanism whereas a thickwalled can fail by forming a flip desk mechanism [8,12] as shown in Fig. 5(c). Static bending tests (2nd caption in Fig 3) to simulate live loads to AS 1170.1 and to mimic cyclonic wind speeds (85 m/s) and non-cyclonic wind speeds (50 m/s) to the Australian wind loading code AS 1170.2 will be performed. Additional bending tests will be performed to simulate snow loads to Australian wind loading code AS 1170.3. Shear tests as shown in Fig. 5(a, b) will be performed to simulate any possible shear and twist that can be experienced by the BIPVT panel during wind gusts during severe cyclones in North-West parts of Australia.

Theoretical models will be developed to predict the collapse of thin-walled profiles. Thin-walled structures are capable of carrying substantial loads, deflecting far beyond their elastic or buckling limits. The collapse of such structures under load involves the formation of plastic hinges for both open and closed profiles. These plastic hinges are best described as local plastic spatial mechanisms, because they involve large localised plastic deformation with geometric folding [8, 12], Most of the plastic deformations for these sections are concentrated at the plastic hinges, except in a few situations where plasticity is spread over the length of the structure. In certain failure modes, thinwalled structures can act as good energy absorbers. Therefore, certain thin-walled structural components can be designed specifically for such purposes. During the process of energy absorption, thin-walled structures undergo very large deflections forming complex though often ordered patterns of folds and wrinkles. The order of deformation can be as high as the linear dimension of the structure. Fig. 5(c) shows theoretical models developed by Cl-Karrech [8] and Cl-Elchalakani [12] to predict the collapse behaviour of thick and thin-walled panels under axial loading. These analytical models will be extended to predict the behaviour of the BIPVT composite panel under different loading conditions.

The concrete damage plasticity constitutive model developed by Cl-Elchalakani [7] and shown in Fig. 6 will be adapted for lightweight geopolymer in this patent. The constitutive model will be calibrated and implemented using finite element modelling (FEM), by taking into account the degradation of properties, using a damage state variable (Fig 6a), and the plastic flow using a tear-drop like yield function (Fig 6b). The yield function size will be dependent on the history of loading to reflect the geopolymer hardening equivalent plastic strain in both compression and tension and will be used to define the strength of geopolymer under different loading conditions. Uniaxial stress-strain relationship of geopolymer under compression and tension will be instrumental to represent the shape of the variation of yield surface with respect to the equivalent plastic deformation. Like in the case of concrete, the volume change caused by plastic distortion will be represented by a plastic potential function that follows a Drucker Prager hyperbolic function [13], Design recommendations for the BIPVT panel will be proposed for a range of field applications, based on the experimental study on the material properties of geopolymer (Task 1) and BIPVT structural testing (Task 2) along with the theoretical and numerical modelling of BIPVT panel. Design rules will be carefully developed for the possible inclusion in the design codes for FRP reinforced composite structures (e.g., ACI 440 [15]). The research team experience relevant to this Task can be assessed through these papers [5-10, 12],

Task 3: Mechanical tests for heat exchanger and piping system

The performance of Half-Cell mono crystalline silicon PV laminate is significantly affected by ambient conditions such as temperature. Test results show that only 10% to 20% of the solar radiation is

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2020100634 26 May 2020 converted into electrical energy by the PV while the remaining is dissipated as heat, which increases the surface temperature of the cells and reduces its conversion efficiency with a power reduction coefficient of 0.5 - 0.65% °C-1 [3, 24], As such, a back surface cooling technique based on convection heat transfer is employed in this patent to maintain the PV cells average temperature at a minimum value with a uniform distribution to increase the PV conversion efficiency. In the same time solar radiation heats up the water circulated in the flat pipes under the PV cells for various residential applications based on Newton's law of cooling, Q=h( Ts-Tf ) where Q. is the rate of change of the PV temperature, h is the convective heat transfer coefficient, Ts is the PV surface temperature and Tf is the water temperature [3], The preliminary design indicated that for the case of 1100 W/m2 irradiation with 66 l/min (=1.1 g/s) water flow, the water temperature increases from the heat exchanger inlet temperature at 20 0C to the outlet at 64 0C. Thus, the thermal power collected by water is Ewater = mwater x Cwater x 0Twater = 1.1 g x 4.18 W/g 0C x (64-20) 0C = 202.3 W/m2. Note, mwater=l.l g/s is the water mass flow rate, and Cwater =4.18 joules/g is the specific heat of water. Conservatively assuming the PV net undegraded output of 330 W/panel (=165W/m2) due to cooling effect, thus, the expected total energy efficiency will be (165+202.3)/1100=33.4%. This efficiency is more than double the efficiency of the traditional PV panels [1-3], This predicted efficiency will be confirmed by the mechanical tests proposed in this task.

The optimum geometrical dimensions and pattern of the Heat Exchanger (HE) pipes will be determined through comprehensive numerical modelling and experimental testing to ensure minimal PV half-cell temperature with uniform distribution within the entire PV array. Different materials will be examined for optimal performance for the HE such as Aluminium, copper, stainless steel and galvanized steel. Thermocouples will be attached to the panel to measure its temperature and an insulation material will be manufactured using a highly porous cementitious composite made from recycled industrial waste to enhance the performance. The proposed insulation material will be produced by adding alumina powder to the cement water mixture and lightweight high volume materials such as perlite, pumice or foam will then be incorporated. Different types and contents of lightweight sand, fly ash, slag and micro silica will be examined to obtain the best mix. The insulation material in this form will be recyclable cementitious-based materials allowing the BIPVT panel to be reused as a backfill material after completing its operational service and crushing it into granular form. In addition to the cementitious-based layer of insulation, another soft isolation layer will be used around the HE to enhance the overall insulation performance and to isolate the HE layer from the structural geopolymer layer. This isolation is necessary to eliminate the possibility of damage to the geopolymer during structurally and thermally induced deformation. Glass wool or extremely lightweight autoclaved aerated composite will be utilised for this purpose. The optimum HE and piping design will be determined by extensive mechanical tests including: different flow rates; different geometrical patterns, different BIPV panel temperatures; a number of mechanical connections; and different designs for the hot water tank.

One of the main design challenges is to avoid the obstruction of the HE pipes passing through a section of the BIPVT panel during production which will be overcome through these planned stages: (1) laminating the HE pipes using lightweight thin isolation layer and the PV layer to form the thermal/photovoltaic (HE/PV) element; (2) placing the insulation layer at the bottom of the formwork and then placing the FRP mesh; (3) casting the geopolymer to form the structural element; (4) laminating the structural element to the HE/PV element; and (5) steam curing for 48 hours. An established technique used to manufacture cement fibre boards in Australia will be adapted for BIPVT panels. This technique is commonly used in the construction industry using an autoclave, which is suitable for the mass production of BIPVT panel arrays in the future. The research team experience relevant to this Task can be assessed through these samples of their publications [5-10, 12, 14, 15],

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Task 4: Electrical performance and condition monitoring technique

One of the significant drawbacks of today's PV roof arrays is the several exposed noncurrent carrying metal parts including mounting racks and brackets, module frames and metal enclosures. These parts make the PV array more prone to short circuit faults when a conducting part exhibits corrosion, water leakage, insulation damage, wrong wiring or due to overheating. One feature of the BIPVT panel is the disuse of such conducting materials and hence, the likelihood of short circuit faults is significantly reduced. Also, the panel will not suffer overheating because the built- in heat exchanger will absorb the heat and transfer it for various house applications. With the rapid increase in the rooftop PVs production, adopting a cost-effective condition monitoring and fault diagnosis technique has become essential. Various faults such as short circuit (intra and cross-string), open circuit (high series impedance) and ground faults along with the aging degradation and unexpected events (partial shading) as shown in Fig. 7 must be detected at early stages to avoid any catastrophic consequences and facilitate a proper and timely asset management decision. Undetected faults within the traditional PV array due to poor design may result in electrocution and fire hazards as shown in Fig. 2(b). In the developed BIPVT panel, a residual current monitoring system will be used as a ground fault protection device to detect and isolate ground faults within the PV system. For faults of low undetected current by this protection system, a new condition monitoring technique based on the PV voltage-current (VI) characteristics will be developed. The PV array comprises nonlinear V-l characteristics that depend on several factors including temperature, insulation, equivalent electric circuit parameters, and load demand. Any of the PV potential faults shown in Fig. 7 along with the PV performance degradation due to aging, shading and other disturbance events will affect the V-l characteristics and hence the maximum power point tracking (MPPT) operation within the inverter. These changes will be detected in real time and an early-stage warning signal will be issued such that proper actions can be taken on a timely manner. This alarming signal will be shown on the inverter panel and can be transferred wirelessly to a smart device such as a mobile phone in real time.

The performance of PV along with the inverter and the energy storage battery (see Fig lb) will be investigated by measuring the voltage-current-power characteristics at different operating temperatures. In this regard, a series of laboratory tests will be conducted at Curtin University to investigate the impact of various fault types, levels and locations on the V-l characteristics of the developed panels under different environmental and operating conditions. Based on the obtained results, a digital image processing / Artificial intelligence-based code will be developed to detect such incipient faults and unexpected events and issue a warning signal through a wireless application on a smart device/computer. Cl-Abu-Siada has two filed patents on a similar technique applied for power transformers and transmission lines fault detection in real time, the patented technique is currently applied on a 220kV substation transformer for real field validation.

Another major operational challenge of the traditional PV system is the variability in its output power, which is mainly caused by the movement of clouds as can be seen in Figs. 8(a), (b). For the application of the BIPVT panel in a large area such as refugee camps, this variability can be reduced by distributing the BIPVT systems within the area; this is often referred to as geographic smoothing. The robustness of this solution is shown in Fig. 8(c), which reveals that the irradiance is getting smoother by increasing the number of the PVs distributed over a geographical area. This smoothing is expressed mathematically by a variability reduction index (VRI), which denotes the reduced level of variations in the output power of a group of neighbouring PV systems. VRI considers the size of the PVs, the distances between them, as well as the mathematical correlation model that reflects the timescale, along with the speed, direction and density of the clouds passing over the PV systems. The VRI and solar irradiance, at one location using a PV pyranometer sensor will be used to estimate the power

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2020100634 26 May 2020 generated by a group of neighbouring PV systems under cloudy or PV partial shading conditions. This will facilitate reliable estimation of the overall PV generated power during short term irradiance fluctuation due to unexpected passing clouds of unknown size, direction and speed, which may result in frequency instability due to the reduction in the generated power. According to utilities guidelines, the PV output power reduction should not be more than 10% of the PV capacity over a minute. This challenge will be overcome through distributing multiple BIPVT systems over a geographical area and/or by utilising a suitable backup energy storage system. The research team experience relevant to this Task can be assessed through these publications [16-22],

Task 5: Practical testing of the BIPVT system performance

Upon the accomplishment of the above 4 Tasks, the entire developed system will be examined by constructing a 70 m2 testing facility using 20 BIPVT panel arrays of 6.6 kW capacity along with a battery storage, inverter, piping system, hot water storage tank, electric pump and control valves and sensors. The developed online condition monitoring technique as well as the estimation of power output over various seasons using one sensor will also be tested. This facility will be a self-sufficient and a true net zero energy model house as shown in Fig. 1(b) and will be built in Curtin University as a charging facility for students' electric scooter and motor bicycles. The model house will also be used as an education and research facility. Pl-Nayar, through his vast practical experience as can be noted from the patents that he successfully constructed around the world, will have a significant role in building this facility along with his guidance on the performance testing at each stage of the BIPVT panel development.

1.3 INVESTIGATORS

Cl-Elchalakani will lead the patent and be involved in all phases of the patent, including overall coordination and strategic development. He is an expert in sustainable composite materials and structures. He will lead the development of the geopolymer composite and structural tests required in Tasks 1-2. Cl-Elchalakani will supervise the PhD student, co-supervise the Senior Research Associate (SRA) and 3 Honours students, and he will spend 4 days per month (0.2 FTE) on the patent. The research profile of Cl-Elchalakani is internationally recognised through significant research contributions to the field of development and application of plastic methods of analysis of geopolymer and composite structures, and strength assessment and rehabilitation of civil infrastructure. This is demonstrated through an extensive refereed publication record, invitations to international conferences as a keynote speaker and to present lectures and seminars locally and internationally, his research leadership of the repair and assessment of offshore structures at UWA and his substantial research funding. Cl-Elchalakani serves on the editorial board of a number of key journals. He published 106 journal papers and 71 conference papers where most of these publications are related to Tasks 1-2. His Google Scholar citations are in excess of 2300 and his h-index is 25. His Scopus citations are in excess of 1600 and his h-index is 21. His Research Gate score is 35.0 which is more than 92.5% of its registered users worldwide. His research funding to date totals more than $1.1 million in cash from industry supported patents and consulting work. A total of 8 PhD students are progressing well in their research under his supervision at UWA. Cl-Elchalakani received several awards, including the Hunt Award and Holman Medal for excellence in Research in Engineering. He also received the prestigious Japanese Society for Promotion of Science Fellowship, in addition to receiving a number of industry grants at Victoria University and UWA. Cl-Elchalakani is a registered building practitioner and a chartered professional engineer in Australia, Asia and Egypt where he has collaborators in wellknown universities worldwide.

Cl-Abu-Siada will supervise the SRA and 3 Honours students, he will spend 4 days per month (0.2 FTE) on the patent and will lead the investigations in Tasks 4-5. He has extensive experience in condition

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2020100634 26 May 2020 monitoring, fault diagnosis and PV research topics and has recognised credentials at national and international levels necessary to complete the electrical tasks of the patent within the given time frame and without exceeding the requested budget. Most of the Cl's publications (over 250) and supervised HDR theses (21 completed theses) are relevant to this research topic. The Cl has supervised a PhD thesis entitled Short-term prediction of the output power of a group of neighbouring PV plants in the same research field, in which a new estimation technique for a group of neighbouring rooftop PVs is developed and published in one of the top IEEE transactions (IF 7.37). Most of the Cl's publications in condition monitoring and fault diagnosis have been published in the most prestigious IEEE transactions; some examples include IEEE transactions on Sustainable Energy (IF 7.65), Industrial informatics (IF 7.37), power Electronics (IF 7.15), Industrial Electronics (IF 7.5) and Power Delivery (IF 4.4) in which some of the techniques of this research proposal including V-l, Al, FEM, and image processing are presented. The Cl has been granted two CRC patents relevant to the topic of this research and received two international grants in collaboration with the State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, China (ranked 21) in the same research field. The Cl has a patent on a novel online condition monitoring technique for power transformer. This patent has been highlighted in The Australian newspaper and filmed on YouTube and has attracted investors from the USA, Singapore, Germany and South Africa who contacted Curtin commercialization to express their interest in this invention. In Collaboration with Chongqing University (China), this patent has been implemented and installed at a substation in China for practical trials and field assessment. A Similar technique will be adopted for the PV online condition monitoring in this proposal.

1.4 FEASIBILITY

In Section E2.3 of the Patent Cost, the estimated cost of the proposed BIPVT 330-Watt panel is $400. This is equivalent to $1.21/W, which is 21.2% higher than the cost of conventional PV panels but features significant advantages such as: saving roof structural elements and associated significant labour cost including roof tiles/cladding, purlins, batten plates, metal racks and brackets; providing free electricity and thermal energy; avoiding short circuit faults; higher PV efficiency due to the cooling effect; and lower temperature inside the house during the hot season. If all these savings are considered, the proposed BIPVT panel will be more cost-effective than most of the options currently available. The patent team is composed of three research active academics from two researchintensive universities, and a PI with extensive industry and research experiences in the same field of this research proposal. The Cis and PI have significant track records, as can be assessed from their relevant publications, patents, research grants and industrial patents. The research team has extensively published papers based on multidisciplinary research topics and has complementary skills to work on broader research areas. The team has also successfully supervised a large number of completed PhD theses. This ensures the technical feasibility and successful completion of the patent, which can be further assessed through the relevant results published by the Cis and the industrial patents performed by the PI. The physics laboratory at UWA is equipped with the state-of-the-art Australian Microanalysis Research Facility that is essential for the chemical tests proposed in Task 1. The structural and mechanical laboratories at UWA are equipped with the necessary testing machines to perform Tasks 2-3. The electrical and computer engineering department at Curtin university hosts three state-of-the-art power simulation laboratories with essential engineering software packages including ANSYS finite element analysis software package, which will be used to complete Tasks 4-5. All technical personnel support, space and computers will be provided by the two universities and the industry partner to the patent at no cost. The patent will appoint one Senior Research Associate with good practical PV technical skills, one PhD student of construction material background and 6 Honours students for the successful and timely completion of all the five tasks. The proposed budget is

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2020100634 26 May 2020 appropriate and mainly covers the costs associated with the required personnel, materials and maintenance of equipment. The proposed system is expected to compete with Tesla roof tiles due to its lower cost, higher durability, sustainability and efficiency.

1.5 BENEFIT

In developing the future renewable system architecture, the international renewable energy agency (IRENA) has identified five remarkable points in this ambitious transformation journey, these are: enabling bi-directional energy flow, proposing improved grid interconnection, adopting enhanced technologies and increasing energy storage capacity. This proposal is aiming at addressing these challenges and paving the way into 100% self-sufficient, green and true net zero energy buildings. The novel seamlessly integrated sustainable system proposed herein aligns well with the Australian government 2030 vision for sustainable cities [23], and we aim it will gain 10 green stars rating from the Green Buildings Council of Australia. The successful completion of the patent will not only enhance the existing knowledge in material and structural engineering fields, but it will open new frontiers for Australia that can extend the capabilities of today's infrastructure with integrated renewable systems. The proposed system is flexible and modular in the sense that a damaged or leaked BIPVT panel can be easily replaced. The application of the proposed BIPVT elements can be extended e.g. connecting it with a compressed air system (heat pump) to provide heating in cold weather without the need for any gas or electrical heating systems. The patent will recycle industry wastes such as slag, fly ash, and silica fume to develop a durable ceramic-like geopolymer composite and will result in a highperformance and sustainable construction technique to mitigate the high carbon footprint of the built environment. The pioneering results of this research will significantly strengthen the international profile of Australia in the areas of sustainable development and advanced manufacturing. The patent results will benefit the utility companies, construction industry and end users by developing a reliable, cost-effective and practical technique to build smart houses equipped with modular solar/thermal energy harvesting elements. The research will open the field for further development in smart and green house technologies to include off-grid charging facilities for electric vehicles, which are expected to dominate the automobile market in the next few years. This will decrease the pressure on electricity utilities as on-grid vehicle charging, if not properly coordinated, may lead to catastrophic consequences including black-outs. It is envisaged that BIPVT units will be available at competitive prices for the end users once they are commercially mass produced. A significant outcome of this patent is the construction of a new large-scale testing facility at Curtin University as a model selfsufficient net zero energy house. Such a facility will be available for future renewable energy patents. One SRA, one PhD student and 6 Honours students will be trained in this patent to ensure that the transfer of intellectual capacity to a new generation of researchers in Australia is accomplished. The patent outcomes will lead to the applications of cost-effective, environmentally friendly and durable construction materials for the roof structures located in harsh coastal environment instead of the traditional roof tiles/cladding. The proposed BIPVT panel and the net zero energy system can be used in housing patents in a remote aboriginal community in Australia and refugee camps worldwide, and it is also suitable for off-grid, on-grid and micro-grid applications.

1.7 REFERENCES

[1] Shukla, A. K., Sudhakar K., Baredar, P., A comprehensive review and design of building integrated photovoltaic system, Energy and buildings, 128, 90-110, 2015.

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[2] Zuo, J. and Zhao, Z.Y. Green Building Research - Current Status and Future Agenda: A Review, Renewable and Sustainable Energy Reviews 30, 271-281, 2014.

[3] H.M. Yin a, DJ. Yang a, G. Kelly b, J. Garant Design and performance of a novel building integrated PV/thermal system for energy efficiency of buildings, Solar Energy, 87, 184-195, 2013.

[4] Junaid, T. M., Kayali, 0., and Khennane, A. Response of alkali activated low calcium fly-ash based geopolymer concrete under compressive load at elevated temperatures. Materials and Structures/Materiaux et Constructions, 50(1), 1-10, 2017.

[5] Dong, M., Feng, W., Elchalakani, M., Li, G. K., Karrech, A., & May, E. F. Development of a high strength geopolymer by novel solar curing. Ceramics International, 43(14), 11233-11243. doi:10.1016/j.ceramint.2017.05.173, 2017.

[6] Elchalakani, M., Dong, M., Karrech, A., Li, G. Development of Fly Ash- and Slag-Based Geopolymer Concrete with Calcium Carbonate or Microsilica. ASCE, Materials in Civil Engineering, 30, 1-14. 2018.

[7] Elchalakani, M., Karrech, A., Dong, M., Mohamed Ali, M.S., Yang, B. Experiments and Finite Element Analysis of GFRP Reinforced Geopolymer Concrete Rectangular Columns Subjected to Concentric and Eccentric Axial Loading. Structures 14, 273-289, 2018a.

[8] Karrech, A., Elchalakani, M., Attar, M., & Seibi, A. C. Buckling and post-buckling analysis of geometrically non-linear composite plates exhibiting large initial imperfections. Composite Structures, 174, 134-141. doi:10.1016/j.compstruct.2017.04.029, 2017.

[9] Elchalakani, M., 2014. Plastic Collapse Analysis of CFRP strengthening and rehabilitation of welded RHS beams under combined bending and bearing. J. Thin-Walled Structures. 82, 278-295.

[10] Karrech A., Dong M., Elchalakani M., Shahin M.A. (2019), Sustainable geopolymer using lithium concentrate residues, Construction and Building Materials 228, 116740.

[11] Naaman, A.E., 2012. Evolution in Ferrocement and Thin Reinforced Cementitious Composites. Arab. J. Sci. Eng. 37, 421-441.

[12] Elchalakani, M. (2014), Plastic Collapse Analysis of CFRP strengthening and rehabilitation of welded RHS beams under combined bending and bearing, Journal of Thin-Walled Structures, Elsevier, UK, Vol. 82, No. 9, 278-295.

[13] Lubliner, J., Oliver, J., Oller, S., Onate, E., 1989. A plastic-damage model for concrete. Int. J. Solids Struct. 25, 299-326.

[14] Basarir, H., Elchalakani, M., Karrech, A. The prediction of ultimate pure bending moment of concrete-filled steel tubes by adaptive neuro-fuzzy inference system (ANFIS ). Neural Comput. Appl. 1-14, 2017

[15] ACI 440. Guide for the design and construction of concrete reinforced with FRP bars ACI 440.1R-15, 2015.

[16] A. Abu-Siada and S. Islam, A Novel On-Line Technique to detect Power Transformer Winding Faults, IEEE Transaction on Power Delivery, Vol. 27, No. 2, pp. 849-857, April 2012.

[17] A. Abu-Siada, Saif Mir, A new on-line technique to identify fault location within long transmission lines, Engineering Failure Analysis, Vol 105, pp. 52-64, 2019.

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[18] A. Abu-Siada,Power Transformer Condition Monitoring and Diagnosis: Concepts,

Challenges, IET, UK, ISBN:978178561254, 2018.

[19] A. Abu-Siada, I. Radwan , A. F. Abdou, New 3D Approach for Fault Identification within Power Transformers using Frequency Response, IET Science, Measurement & Technology, vol. 13, no. 6, pp. 903-911, 8 2019.

[20] A. Abu-Siada, O. Aljohani, Detecting Incipient Radial Deformations of Power Transformer Windings using Polar plot and Digital Image Processing, IET Science, Measurement & Technology, Vol. 12, Issue 4, pp. 492 - 499, 2018.

[21] A. Abu Siada, Μ. I. Mossad, Dowon Kim, M. El-Naggar, Estimating Power Transformer High frequency Model Parameters using Frequency Response Analysis, IEEE Transactions on Power Delivery, Early Access, doi: 10.1109/TPWRD.2019.2938020, August 2019.

[22] S. Islam, Chem Nayar, A. Abu-Siada, H. Mubashwar, Power Electronics for Renewable Energy Sources, in Power Electronics Handbook, 4th edition, Butterworth-Heinemann, Elsevier, Netherlands, September 2017, pp. 783 - 828.

[23] Australian Government, Report on the Implementation of the Sustainable Development Goals, 2018.

[24] Chow, T.T., 2010. A review on photovoltaic/thermal hybrid solar technology. Applied Energy 87 (2), 365-379, 2010.

Claims (1)

1. Specifications

   The proposed architecturally and structurally integrated panel requires the assemblage of multi-layered materials with different properties in order to achieve self-sufficient energy buildings, which cannot be safely, economically or even ecologically achieved with conventional solar panels. The proposed BIPVT-330 Watt hybrid panel is 2000 mm long, 1000 mm wide and 35 mm thick. It will be made of a 10 mm geopolymer layer, 5 mm FRP mesh layer, 10 mm heat exchanger isolated Aluminium piping, 5 mm thick insulation layer and a 5 mm half-cell mono crystal photovoltaic layer including protective glass surfacing and adhesive. The geopolymer, insulation and isolation materials are all made of lightweight recycled industrial wastes. The proposed BIPVT panel has the advantages of being: seamlessly integrated with the roof profile; self-supported directly on the timber frame and not requiring any roof tiles, cladding, purlins, metal racks or brackets; strong enough to suit sustainable houses in cyclonic regions in Australia; provided with embedded metal pipes to heat up its internal circulated water to provide free thermal energy and at the same time cool down the PV laminate, thereby increasing the conversion efficiency and reducing the temperature inside the house; a safeguard against snow and ice accumulation; and architecturally appealing because it has a slim profile so it can be seamlessly integrated in any roof design. The innovations of the patent include:

   • Developing a geopolymer of “zero-cement” composite fully made from recycled industrial waste such as fly ash, slag, and micro silica. This new composite is sustainable and has a little carbon footprint and exceptional heat resistance.

   • Unlike traditional solar panels that require roof tiles/cladding and support racks, the BIPVT panel does not require roof tiles, cladding, purlins, or metal brackets where it is directly supported on the timber frame. Thus, it is much more cost effective and aesthetically appealing since the panel is seamlessly integrated in the roof profile.

   • Unlike traditional solar panels that can experience short circuits and cause fires, the proposed BIPVT panel does not comprise any exposed external metal cladding or brackets and it has a less fire hazard because of the integrated cooling system. Also, geopolymer has exceptional fire resistance compared to today’s roof tiles.

   • On the contrary of Tesla roof tiles that require extensive roofing support, the proposed BIPVT hybrid panel is self-supporting and for about one-third of the cost of Tesla roofing technology.

   • Unlike the recent PV/thermal panel made from unsustainable complex and thus expensive ($3.67/Watt) functionally degraded materials, the proposed BIPVT panel construction is simple and it is made of recycled industrial waste materials, hence it is a cost effective solution ($1.21/Watt).

   • The proposed BIPVT panels are expected to revolutionise the construction industry by providing multi- functional properties including roofing, generation of clean energy at higher efficiency than the conventional PVs and providing free thermal energy for residential hot water systems.