This literature review supported Optimizing limited solar roof access by exergy analysis of solar thermal, photovoltaic, and hybrid photovoltaic thermal systems - which resulted in the following publication:
- M.J.M. Pathak, P.G. Sanders, J. M. Pearce, Optimizing limited solar roof access by exergy analysis of solar thermal, photovoltaic, and hybrid photovoltaic thermal systems, Applied Energy, 120, pp. 115-124 (2014). DOI: http://dx.doi.org/10.1016/j.apenergy.2014.01.041 Open access
Photovoltaic Thermal Hybrid[edit | edit source]
There is a renewed interest in photovoltaic solar thermal (PVT) hybrid systems, which harvest solar energy for heat and electricity. Typically, a main focus of a PVT system is to cool the photovoltaic (PV) cells to improve the electrical performance. This works well; however, this causes the thermal component to under-perform compared to a solar thermal collector. Recently there has been very promising work, which utilized the low temperature coefficients of amorphous silicon (a-Si:H) PV which allow the PV cells to be operated at high temperatures, creating a more symbiotic PVT system. See: M.J.M. Pathak, J.M. Pearce and, S.J. Harrison, "Effects on Amorphous Silicon Photovoltaic Performance from High-temperature Annealing Pulses in Photovoltaic Thermal Hybrid Devices" Solar Energy Materials and Solar Cells, 100, pp. 199-203 (2012). arXiv. The fundamental challenge of a-Si:H PV is light-induced degradation known as the Staebler–Wronski effect (SWE). Fortunately, SWE is reversible and the a-Si:H PV efficiency can be returned to its initial state if the cell is annealed. Thus an opportunity exists to deposit a-Si:H directly on the solar thermal absorber plate where the cells could reach the high temperatures required for annealing.
Related Appropedia articles[edit | edit source]
- High-temperature annealing pulses in amorphous silicon PVT
- Optimizing limited solar roof access by exergy analysis of solar thermal, photovoltaic, and hybrid photovoltaic thermal systems
- Optimization of annealing cycles for electric output in outdoor conditions for amorphous silicon photovoltaic–thermal systems
IEA TASK 35 PV/T[edit | edit source]
The IEA (International Energy Association) is almost finished their study on PV/T.
They had five subtasks:
- Subtask A: Market and Commercialisation of PV/T
- Subtask B: Energy Analysis and Modelling
- Subtask C: Product and System Development, Tests and Evaluation
- Subtask D: Demonstration Projects
- Subtask E: Dissemination
They looked at 4 different types of PV/T set-ups in multiple countries.
- PV/T liquid collector
- PV/T air collector
- PV/T concentrator
- Ventilated PV with heat recovery
Canada is part of this TASK 35 and is studying Transpired Air PV/T collector at the National Solar Test Facility.
It started in 2005 and ended in 2008. Currently, they are reviewing the final draft. I have emailed the coordinators last week. See the following for contact information.
Everybody with the interest in PV/Thermal Solar Systems are invited to contact
Project Manager Jan Hansen, Esbensen Consulting Engineers A/S, email@example.com, +45 3326 7308
Operating Agent Henrik Sørensen, Esbensen Consulting Engineers A/S, firstname.lastname@example.org, +45 3326 7304,
The website is http://pv-t.org/
The canadian group is: Leader for Subtask B is Michael Collins, University of Waterloo, Canada, funded by Natural Resources Canada.
Here is the annual report of SHC (solar heating and cooling program) SHC Annual Report 2008
Here is another report from IEA SHC overview of current tasks IEA SHC Current Tasks Report
5mjmp 19:12, 1 June 2009 (UTC)
Hybrid PV/Thermal Collectors 2000[edit | edit source]
This paper talks about the current PV/T systems, the future systems and what needs to be done. Isreal (Cromagen) has PV/T's since 1991 and the use water as the cooling medium. Germany has two companies as well; SolarWerk and SolarWatt. "Both systems use plat plate solar heat collectors with PV cells integrated on the absorber." Canada (Conserval Engineering) uses air as its medium.
"PV/T-technology is still very new and there is a strong need for R&D and demonstration efforts in the following areas:
- Maximization of heat transfer from the solar cell to the heat transfer medium and
maximization of the electrical yield from the solar cells for different temperaturelevels.
- Durability testing of collectors and solar cells, especially for laminated solutions and
solutions where the solar cells operate at a high temperature.
- A standardized method of assessing the energy performance of PV/T systems needs
to be defined and calculated, monitored and evaluated both for the commercial products and for the best solutions demonstrated as one-off systems in buildings."
5mjmp 19:41, 1 June 2009 (UTC)
H. SØRENSEN and D. MUNRO. Hybrid PV/Thermal Collectors. The 2nd World Solar Electric Buildings Conference: Sydney 8th-10th March 2000
Commerically Available PVT Products 2006[edit | edit source]
- PVT air collectors
- Aidt Miljo / Grammer Solar / Conserval Engineering
- Ventilated PV with heat recovery
- Secco Sistemi
- PVT liquid collectors
- PVTWINS / Millennium Electric
- PVT concentrators
- Arontis / HelioDynamics / Menova
5mjmp 14:41, 3 June 2009 (UTC)
http://pv-t.org/ under documents
H.A. Zondag. Commerically Available PVT Products. Energy Research Center of the Netherlands. July 2006.
PVT - Untapped Energy 2007[edit | edit source]
The article talks about the potential of PVT's. This article specifically deals with Canada's involvement with Task 35 with PVT's using Air has its heat transfer medium. The testing was done at Canada's National Solar Test Facility (NSTF) indoors under the STC set by the IEA Task 35 group. Several companies supplied some of their PV panels which were then fitted to a thermal system. Test were done and efficiencies were calculated. The total efficiencies (thermal and electric) ranged from 21-56 %. It was found that thermal was 150-400% more efficient than electric for crystalline and up to 800% more efficient for amorphous. However, tests did show that cooling PV panels is more efficient and that it does cool the PV panels making them work better. Up to 0.5%/C better.
5mjmp 14:12, 4 June 2009 (UTC)
J. Hollick and B. Barnes. PV Thermal Systems - Capturing the Untapped Energy. Conserval Engineering Inc. http://web.archive.org/web/20081120220702/http://solarwall.com/media/images-articles/ASESPaper-PVThermalSystems-theUntappedEnergy175A3.pdf
Review Journal Articles[edit | edit source]
Evatuation of Flat-Plate Photovoltaic/Thermal Hybrid Systems 1980[edit | edit source]
The is a study on the economics of whether PV/T's are worth doing compared to PV, Thermal, PV and T (side by side). The study compared glazed and unglazed. The tests were done in Tampa, New York and LA. This study was done in 1980's and concluded that PV/T was not economcially feasible, however, now with better PV, PV/T has a second chance.
John W. Andrews
DEPARTMENT OF ENERGY AND ENVIRONMENT SO LAR TECH N 0 LOGY G RO U P BROOKHAVEN NATIONAL LABORATORY ASSOCIATED UNIVERSITIES, INC. UNDER CONTRACT NO. DE-AC02-76CH00016 WITH THE UNITED STATES DEPARTMENT OF ENERGY
BNL 51435 uc-59c (Heating and Cooling-Research and Development - TIC-4500
5mjmp 19:00, 1 June 2009 (UTC)
Photovoltaic thermal (PV/T) collectors: A review 2007[edit | edit source]
Abstract: This paper presents a review of the available literature on PV/T collectors. The review is presented in a thematic way, in order to enable an easier comparison of the findings obtained by various researchers, especially on parameters affecting PV/T performance (electrical and thermal). The review covers the description of flat plate and concentrating, water and air PV/T collector types, analytical and numerical models, simulation and experimental work and qualitative evaluation of thermal/electrical output. The parameters affecting PV/T performance, such as covered versus uncovered PV/T collectors, optimum mass flow rate, absorber plate parameters (i.e. tube spacing, tube diameter, fin thickness), absorber to fluid thermal conductance and configuration design types are extensively discussed. Based on an exergy analysis, it was reported that the coverless PV/T collector produces the largest available total (electrical + thermal) exergy. From the literature review, it is clear that PV/T collectors are very promising devices and further work should be carried out aiming at improving their efficiency and reducing their cost, making them more competitive and thus aid towards global expansion and utilization of this environmentally friendly renewable energy device.
Photovoltaic thermal (PV/T) collectors: A review. P.G. Charalambous, G.G. Maidment, S.A. Kalogriou and K. Yiakoumetti. Applied Thermal Engineering 27 (2007) 275–286
5mjmp 16:38, 16 September 2009 (UTC)
09_09_16_Photovoltaic thermal (PV-T) collectors A review.pdf
Flat-plate PV-Thermal collectors and systems: A review 2008[edit | edit source]
Abstract: Over the last 30 years, a large amount of research on PV-Thermal (PVT) collectors has been carried out. An overview of this research is presented, both in terms of an historic overview of research projects and in the form of a thematic overview, addressing the different research issues for PVT.
Flat-plate PV-Thermal collectors and systems: A review. H.A. Zondag. Renewable and Sustainable Energy Reviews 12 (2008) 891–959
5mjmp 18:08, 16 September 2009 (UTC)
09_09_16_Flat-plate PV-Thermal collectors and systems A review.pdf
A review on photovoltaic/thermal hybrid solar technology 2009[edit | edit source]
Abstract: A significant amount of research and development work on the photovoltaic/thermal (PVT) technology has been done since the 1970s. Many innovative systems and products have been put forward and their quality evaluated by academics and professionals. A range of theoretical models has been introduced and their appropriateness validated by experimental data. Important design parameters are identified. Collaborations have been underway amongst institutions or countries, helping to sort out the suitable products and systems with the best marketing potential. This article gives a review of the trend of development of the technology, in particular the advancements in recent years and the future work required.
Chow TT. A review on photovoltaic/thermal hybrid solar technology. Appl Energy (2009), doi:10.1016/ j.apenergy.2009.06.037
5mjmp 20:29, 16 September 2009 (UTC)
09_09_08_a review on PVT (2009).pdf
PV/T Journal Article Reviews Anything before the 1990's[edit | edit source]
A Two Dimensional Thermal Analysis of a New High-Performance Tublar Solar Collector 1978[edit | edit source]
Does not involve PVT but just heat transfer of a solar collected. Useful equations but not really related.09 05 28 a two dimensional thermal analysis of a new high-performance tublar solar collector.pdf 5mjmp 19:54, 1 June 2009 (UTC)
A Two Dimensional Thermal Analysis of a New High-Performance Tublar Solar Collector. F.L. Lansing and C. S. Yung. DSN Engineering Section Report 42-49. 1978. http://tmo.jpl.nasa.gov/progress_report2/42-49/49P.PDF
Testing Procedures for Solar Air Heaters, a Review 1988[edit | edit source]
This article does not relate to PVTs. However, it does talk about various methods to standardize testing for the thermal collector part. It suggest ways of making the test repeatable and to be able to reproduce outdoor conditions indoors. It also has heat transfer equations to create an analytical model of the solar air heater. As well as different designs to collect the heat better such as the normal flat plate, triangular duct and fins.
5mjmp 14:56, 26 July 2009 (UTC)
5mjmp 20:23, 1 June 2009 (UTC)
Energy Convers. Mgmt Vol. 32, No. 1, pp. 11-33, 1991. RAM CHANDRA and M. S. SODHA Testing Procedures for Solar Air Heaters, a Review. http://sfx.scholarsportal.info/queens?sid=google&auinit=R&aulast=Chandra&atitle=Testing+procedures+for+solar+air+heaters:+A+review.&title=Energy+conversion+and+management&volume=32&issue=1&date=1991&spage=11&issn=0196-8904
PV/T Journal Article Reviews 1990's[edit | edit source]
Experimental Study on a Hybrid Photovoltaic-Thermal Solar Water Heater and its Performance Predictions 1994[edit | edit source]
This article talks about the potential of PV/T's. The system that was tested as a thermosyphon ([]) water heater. Theorectical calculations were completed and they matched within error of the experimental data. They tested with and without a thermosyphon. It was found that the electrical and thermal efficiencies were 3.35% and 33.5%. A valid assumption is that the average cell temperature is the same as the average plate temperature.
Energy Convers. Mgmt Vol. 35, No. 7, pp 621-633, 1994. H. Garg, R. Agarwal and J. Joshi. http://sfx.scholarsportal.info/queens?sid=google&auinit=HP&aulast=Garg&atitle=Experimental+study+on+a+hybrid+photovoltaic-thermal+solar+water+heater+and+its+performance+predictions&title=Energy+conversion+and+management&volume=35&issue=7&date=1994&spage=621&issn=0196-8904
5mjmp 17:55, 8 June 2009 (UTC)
The Effect of Collector Aspect Ratio on the Collector Efficiency of Flate-Plate Solar Air Heaters 1994[edit | edit source]
This article concluded that the collector efficiency increased with increasing the aspect ratio (L/B). The area of the collector remaind constant but the ratios changed. The ratios were 1/6, 2/3, 3/2 and 6/1. The best one was 6/1. In this paper they completed experimental and theoretical calculations. It was found that the experimental and theorectical values matched within reason expect for the 6/1 where the experimental efficiencies were found to be lower. This is believed to be the result of making the assumption that the loss coefficient Ub from the bottom and surface of the solar collector with respect to teh ambient is negligible. In this paper the reynolds, nussel number and other equations can be found for the theoretical calculations. The experimental procedure can also be found.
5mjmp 14:49, 28 July 2009 (UTC)
5mjmp 20:23, 1 June 2009 (UTC)
Energy Vol 20, No 10, pp 1041-1047, 1995. The Effect of Collector Aspect Ratio on the Collector Efficiency of Flate-Plate Solar Air Heaters. HO-MING YEH and TONG-TSHIEN LIN. http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/4027
Recent Developments of Silicon Thin Film Solar Cells on Glass Substrates 1999[edit | edit source]
The thin film cells are placed on a transparent conductive oxide (TCO)/ glass substrate. The efficiency found was 8%. Although amorphous silicon cells efficiency is 5-7%, there is potential for a-Si to be cheaper than the thin film and with further research become a better cell than thin film. This paper explores some of the costs, TCO material options and how TCO substrates work with a nice diagram. This paper also only looks at p-i-n junctions rather than n-i-p junctions. a-Si have lower processing temperatures and are the thinnest cells.
"Features of the a-Si technology The interest in the a-Si technology is based on several attractive features, namely:
- Si-based technology, implying an abundant material
supply and non-toxic constituents,
- low process temperatures, facilitating low-cost substrate
materials, like oat-glass, moderate energy consumption, and short energy payback times,
- large-area deposition process by plasma-enhanced
chemical vapor deposition (PECVD),
- two-terminal stacked cell structures to allow for higher
voltage/lower current devices, and for the incorporation of different band gaps for extended spectral response (see Section 3.1),
- monolithic series connection of cells to modules, and
hence variability of output voltages (see Section 3.2),
- rear side encapsulation (see Section 3.2),
- low temperature coefficients of the photovoltaic data,
- substantial cost reduction potential, as indicated by a
recent study, funded by the European Commission under the APAS program  (see Section 5). For completeness some of the drawbacks of the a-Si technology are not to be ignored, in particular:
- the photostabilization effect (Staebler±Wronski effect
), and hence
- moderate stabilized ef®ciencies that for modules in
production currently are 5±7%, and for facilities presently coming on line are announced to be around 8%." -paper
5mjmp 16:03, 25 July 2009 (UTC)
5mjmp 20:23, 1 June 2009 (UTC)
Thin Solid Films 351 (1999) 241±246. C. Beneking, B. Rech, S. Wieder, O. Kluth, H. Wagner, W. Frammelsberger, R. Geyer, P. Lechner, H. RuÈbel and H. Schade. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW0-3X9RXD3-1S&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=dbaadd05fff378ba65dbfe09f4cdafa2
PV/T Journal Article Reviews 2000's[edit | edit source]
Derivation of Efficiency and Loss Factors for Solar Air Heaters 1981[edit | edit source]
This article goes through the derivation of efficiency and loss factor using the Hottel-Whillier-Bliss equations. The derivations are for a flat and lee-congrated surface absorber. Flow under the absorber was also calculated. Furthermore, a triangular duct design was calculated too. A caution in the discussion warned the reader that this approximation wields larger errors for air type collectors rather than liquid since liquid usually exhibits smaller changes in temperature along the flow path.
solar Energy Vol. 26, pp. 27-32. DERIVATION OF EFFICIENCY AND LOSS FACTORS FOR SOLAR AIR HEATERS. BLAINE F. PARKER. 1981. http://adsabs.harvard.edu/abs/1979sun.....1..244P
5mjmp 18:33, 5 June 2009 (UTC)
Comparative study of the performances of four photovoltaic-thermal solar air collectors 2000[edit | edit source]
This paper used hourly solar intensity and ambient temperature data and using it in simulations. Four common PVT models were used; air flow over the absorber (I), under the absorber (II), on both sides of the absorbers in a single pass (III) and double pass (IV). The efficiencies took into account everything such as the energy required to run the fan. It was found that the efficiencies of models II-IV were very similar and better than model I. However, the best model was III since it used the least amount of energy to run the fan to produce the same results as model II and IV. The overall efficiency of model III was 57.3%. Selective coatings were also tested but it was found that it did increase the overall efficiency since the thermal efficiency increased but the electrical efficiency did decrease which is the more useful product of the two.
09_06_16_Comparative study of the performances of four photovoltaic-thermal solar air collectors
Energy Conversion & Management 41 (2000) 861±881. Comparative study of the performances of four photovoltaic/thermal solar air collectors. Adel A. Hegazy. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V2P-3Y6GXGH-6&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=ad93859b071bf8be1e6d5bf0ed5be620
5mjmp 20:46, 18 June 2009 (UTC)
The DOE Office of Solar Energy Technologies' Vision for Advancing Solar Technologies in the New Millenium 2000[edit | edit source]
This journal article is not relavent at all. It talks about the US initative to adding solar (electricity, light and heat) to reducing the current loads. I feel very few of this goals and objectives have been reached. This paper just shows that solar is still in the beginning stages of becoming a energy source.
5mjmp 20:23, 1 June 2009 (UTC)
Solar Energy Vol. 69, No. 5, pp. 363–368, 2000. THE DOE OFFICE OF SOLAR ENERGY TECHNOLOGIES' VISION FOR ADVANCING SOLAR TECHNOLOGIES IN THE NEW MILLENNIUM. JAMES RANNELS. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V50-41MHFG3-2&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=530364d05cabb7fba008b13049f0d083
Development and application for PV Thermal 2002[edit | edit source]
The paper looks at many different combinations of PVTs and the efficiency. The PVTs were all built and tested.
Serveral concepts were analyzed:
- none, one, two top covers
- sheet-and-tube constructions vs channel construction
- adding a secondary absorber beneath the PV
Material choices could have been extended with other possiblities such as:
- type of PV; monocrystalline silicon, multicrystalline silicon, a-Si, CIS or other
- what cover material such as teflon instead of glass
- what collector medium (water, air,etc)
- what absorber medium (coper, plastic, etc)
With Sheet-and-Tube, one and no cover were tested adn it was foudn that the presences of the cover top increased the thermal efficiency but decreased the electrical efficiency.
Two absorber PVT collector where the PV-laminate was the primary absorber and a black copper was the secondary absorber which was located beneath the PV. To make this concept work, the primary absorber needs to be as transparent as possible.
Heat pumps were also used. It was found that the used a heat pump uses a fair bit of electricity but the simulations show that the PVT collector can produce more electricity than required by the heat pump. However, this does lower the electrical efficiency but it raises the thermal efficiency.
The best PV efficiency was an uncoverd collector with a heat pump.
09_06_16_Development and application for PV Thermal
Development and application for PV Thermal. H. Zondag, M. Jong and W. Helden. Energy research Centre of the Netherlands (ECN). http://web.archive.org/web/20070112062006/http://www.ecn.nl:80/docs/library/report/2001/rx01025.pdf 5mjmp 14:22, 18 June 2009 (UTC)
The Yield of different combined PV-Thermal Collector Designs 2003[edit | edit source]
The paper states that PVT are better than the side-by-side design previously used. The paper states that there are many advantages to using a PVT system; use less space than side-by-side, provide architectural uniformity and because it is one system there is a possible reduction in installation costs.
In this paper the thermal and electrical efficiency and the annual yield of 4 types of PVTs.
- Can have multiple top covers
- Greater than 2 creates very large reflection which reduces the electrical efficiency
- Can have multiple top covers
- Constraints - choice of collector fluid
- collector fluid affect the absorbtion of the PV - water decreased the electrical performance by 4%
- Need to make sure glass panel can withstand the water pressure
- Transparent PV laminates cost more
- Backside of PV laminate need to be water tight
- Constraints - choice of collector fluid
- Free Flow
- This design eliminates one glass layer
- Increased heat loss due to evaporation
- "Water seems like a natural choice, but, since its evaporation pressure is not very low, evaporation will be shown to create problems at higher temperatures" - Paper
- Efficiency could be improved by adding a transparent insulating layer between the primary and secondary channel to reduce teh heat loss
"High transparent plastics would probably give a small increase in optical efficiency, but their materials properties, such as sensitivity to UV or high temperatures as well as limited watertightness would problably limit thier application in PV-Thermal" -Paper
In this paper all the different types of PVTs were model and all the equations and steps can be found in the paper.
Since the single cover sheet-and-tube can be build from well known components and that were commerically avaible, it was chosen to do experimental tests on to compare to the experimental results. The results matched. It was found that the channel PVT had the best thermal efficiency of 65%.
09_06_16_The Yield of different combined PV-Thermal Collector Designs
Solar Energy 74 (2003) 253–269. T he yield of different combined PV-thermal collector designs. H.A. Zondag, D.W. de Vries, W.G.J. van Helden, R.J.C. van Zolingen and A.A. van Steenhoven. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V50-48GVJHW-6&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=3f51825c92679230619ac95fdb5123fe
5mjmp 20:48, 19 June 2009 (UTC)
Dynamic Performance of Hybrid Photovoltaic-Thermal Collector Wall in Hong Kong 2003[edit | edit source]
In this paper, two different hybrid modules were simulated using hourly TRY (Test Reference Yearly) weather data from 1989. They simulated an EPV (thin cell) and a BPV (single silicon cell). The equations used are found in the paper and the flow chart of the FORTAN code as well. Theorectically PV/T total efficiency is supposed to range from 60-80%. In the simlation the PV/T was on the west wall of a building (facade integrations) and water was used as the coolant. A good quality PV should have an efficiency of 10% after all the loss factors are taken into account. It was found that the electrical efficiencies of EPV and BPV were 4.3% and 10.3% and the thermal efficiencies were 47.6% and 43.2%. However, the EPV system had 217 days compared to 195 days were the water reached 45 C. Also, compared to a normal concrete wall, the EPV and BPV systems' reduction of space heat gain reached 53% and 59.2%.
Building and Environment 38 (2003) 1327 – 1334. Dynamic performance of hybrid photovoltaic/thermal collector wall in Hong Kong. Jie Jia, Tin-Tai Chowb and Wei Hea. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V23-492029K-1&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=d35388b2dfe4bc352501612093350bee
5mjmp 14:51, 8 June 2009 (UTC)
Field Experiments and Analysis on a Hybrid Solar Collector 2003[edit | edit source]
In this testing of the hybrid system, brine was used as the coolant. Single-junction crystalline silicon photovoltaic cells were used. The panels were tilted 30 degrees to optimize teh annual global irradiance. This was done at the Hokkaido Univeristy, Japan. The brine solution was propylene glycol (30 wt %) and the flow rate was 1 l/min. Throughout the experiment the brine temperature ranged from 10-40 C. The efficiencies found experimentally for thermal, electrical and hybrid energy production were 46.2%, 10.7% and 42.6%. Exergy analysis was done as well and the efficiencies were 4.4%, 11.2% and 13.3% for thermal, electrical and hybrid energy conversion. The hybrid system is predicted to reduce the panel area installation area by 27%.
Applied Thermal Engineering 23 (2003) 2089–2105. Field experiments and analyses on a hybrid solar collector. Hisashi Saitoh, Yasuhiro Hamada, Hideki Kubota, Makoto Nakamura, Kiyoshi Ochifuji, Shintaro Yokoyama and Katsunori Nagano. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V1Y-49202TM-2&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=09b52035f6d395197dfc5db91cfc675c
5mjmp 15:24, 9 June 2009 (UTC)
PVT System, PV Panels Supplying Renewable Electricity and Heat 2004[edit | edit source]
"The first systematic research into the possibilities of combining photovoltaic and solar thermal techniques was performed in the early 1980s by a group at MIT.4 In this comprehensive study, several PVT designs were made and tested, both air-type and water-type. The work was discontinued because of a change in government funding. The PVT research regained attention in the mid 1990s with, amongst others, the PhD work of De Vries at the Eindhoven University of Technology.5 He designed several PVT module concepts, of which one was realised and tested. A numerical model was developed calculating both electrical and thermal performance. The model predictions were found to agree with the experimental results.1 The work was continued with a development Figure 3. Prototype of a covered PVT collector programme at the Energy research Centre of the Netherlands ECN.6 In collaboration with industry and the EUT the thermal performance was further optimised and a production technology was developed.7 Bakker investigated another PVT concept, a two-absorber module, at ECN.8 In recent years, several other research groups worked on the topic of PVT. At the University of Patras in Greece, a broad range of PVT geometries for PVT panels were designed, built and tested.9 PhD research on a PVT design with a concentrating reflector is being performed in Sweden.10 In Norway, a concept is developed in which a plastic thermal absorber is used.11 Work on the application of thin-film PV in PVT concepts was carried out in Switzerland.12,13 From a more complete overview of the literature on PVT collectors14 it can be concluded that the research and development activities on PVT are widespread over the world and conducted in relatively small programs. Owing to this dispersion there was little attention for PVT from the PV R&D community. As a result the PVT development had to restrict itself to the application of market-ready PV technologies." - Paper
This paper does a very good job doing an overview of PVTs with their advantages, types, areas of improvement and what has been done in the past and currently. The different types discussed were air, water, double and single pass, combinations and multiple layering, covered or uncovered. The reason PVTs are a good idea is that they increase the overall efficiency (electrical and thermal), smaller energy and cost payback time and aesthetics.
- Emission of heat - losses from convection and radiation. Radiation losses can be reduced by adding a low emissivitive material (double glazed) but the problem is the traparency is reduced to 60-80% which is too low for the use in PVTs. Therefore new materials will need to be studied for the selective coatings
- Solar absorbtion - Ways to improve the absorbtion are to increase the active cell area and metallisation the cells and system (dope with metal). However, metallisation has a high reflection coefficent but there are ways two increase the absorption. Add suitable coatings and reduce the area that needs has the metallisation are ways to improve the absorption.
- Internal heat transfer - the system needs to have a good thermal conductivity to remove the heat from the system.
- PVT module reliablity - The PV panels need to be able to take high temperatures (~125 C) and the need to be able to take the stress of being hot and then cold quickly (once the colding medium is being used).
Another suggestion is making the PV cells transparent then a lower lower cell temperature can be achieved and maintained rather than geometries with heat and electricity generation in the single plane. An example of geometry is spacing the cells out to allow light to pass through and go directly to the absorber.
Prog. Photovolt: Res. Appl. 2004; 12:415–426 (DOI: 10.1002/pip.559). PV Thermal Systems: PV Panels Supplying Renewable Electricity and Heat. Wim G. J. van Helden1, Ronald J. Ch. van Zolingen and Herbert A. Zondag. http://www3.interscience.wiley.com/journal/109605024/abstract
5mjmp 15:54, 12 June 2009 (UTC)
Development and application of solar-based thermoelectric technologies 2005[edit | edit source]
The paper is about a water-cooled PVT and it states that heat production, electicial production, material costs, production costs and installation costs. It also states that for all PVTs "Finding an elegant solution for reducing the size of the collector device, achieving better overall system-efficiency and sharing effectively the balance-of-system costs."-Paper
Extrude Aluminum alloy provides a highly effective heat transfer adn durability. TPT (Tedlar-polyester-tedlar) is a good electrical insulator and EVA (ethylene-vinyl acetate) is an adhesive material. "M/Ac is the mass of water in the thermosyphon system per unit collector surface area."-Paper The smaller the M/Ac the higher the final water temperature.
This PVT used Polycrystalline silicon solar cells and they only covered 50% of the thermal absorber surface. 4.6% of the solar energy was converted into electrical energy and the M/Ac was only 65.2 kg/m2 but the energy saving efficiency was 52% which is higher conventional solar hot water collectors.
09_06_16_Development and application of solar-based thermoelectric technologies
Renewable and Sustainable Energy Reviews 11 (2007) 923–936. Development and applications of solar-based thermoelectric technologies. Hongxia Xi�, Lingai Luo, Gilles Fraisse. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VMY-4GV9B68-1&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=233a7e690a7ce3441fc824a7d9519296
5mjmp 14:53, 19 June 2009 (UTC)
Hybrid Solar Collector 2005[edit | edit source]
This article explores the practicality of hybrid solar collectors. Theoretical calculations were done with the following assumptions The collector is a flat solar one.
- The losses from heat conductivity are neglected since the
layers are very thin and the material they are made of has high thermal conductivity.
- The thermal losses in the photovoltaic cells are disregarded.
- The atmosphere radiates to the collector as an infinite absolutely
black surface with a temperature of the sky, Ts.
The calculations can be found in this paper. The results showed that hybrid collectors use half as much space as PV.
Journal of Materials Processing Technology 161 (2005) 229–233. Hybrid solar collector. V. Lazarov, Chr. Schaeffer, M. Shishkov and M. Ivanova. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TGJ-4DH2GK7-M&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=57a79e6e5285c69739b84b6c77ff0a94
5mjmp 18:25, 9 June 2009 (UTC)
Potential of Applying Hybrid Solar Technology in Hong Kong 2005[edit | edit source]
This paper is about PVT with water as its heat transfer medium. c-Si cells have loss 0.4% / degree drop in efficiency compared to a-Si cells which has an efficiency drop of 0.1% / degree. Therefore, amorphous silicon cells are used in this experiment since they react to temperature rises. Water as a heat medium is suggested in warmer climates due to the better heat exchange. PVT panels were placed on the west and south walls since it was determined from simulations that they has the highest yearly intensities (west was the best). The proposed hybrid system design is described in the article. The efficiencies found were 33.6 % for thermal and 4.6% for electrical and for an amorphous silicon cell.
Potential of Applying Hybrid Solar Technology in Hong Kong. Potential of Applying Hybrid Solar Technology in Hong Kong. Potential of Applying Hybrid Solar Technology in Hong Kong. http://www.irbdirekt.de/daten/iconda/CIB9972.pdf
5mjmp 19:55, 11 June 2009 (UTC)
Performance Evaluation of Photovoltaic Thermal Solar Air Collector for Composite Climate of India 2005[edit | edit source]
This paper studies the performance of PV panel with an air duct. It looks at natural convection, one fan and two fans. They also model using energy balance equations and the experimental results are similar to the predicted results. The results show that a flow rate of about 2m/s, a lenght of ~3 m and a duct depth of 0.03-0.06m produced the optimal efficiency.
Solar Energy Materials & Solar Cells 90 (2006) 175–189. Performance evaluation of photovoltaic thermal solar air collector for composite climate of India. Arvind Tiwari�, M.S. Sodha, Avinash Chandra and J.C. Joshi. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V51-4G1MD85-1&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=67943ffcccf337bf352831d4b64f4406
5mjmp 14:55, 5 June 2009 (UTC)
Study of a New Concept of Photovoltaic-Thermal Hybrid Collector 2005[edit | edit source]
This article is about a 2D thermal model of a PVT/air and comparing to experiemntal results to study the thermal performance. The equations can be found in the paper. The paper looks at the difference between natural and forced airflow. The theory matched the experimental results and that force airflow as better.
"Guiavarch (2003) proposed a modeling of a PV hybrid air collector, which can be integrated in roofs. Hollick (1999) reported the experimental study of a solar collector composed of metal perforated and corrugated sheet steel on which a solar panel is stuck. Then, Belusko (2004) proposed the analysis of a solar air collector with a metal corrugated plate by comparing it to an unglazed solar collector." -Paper
International Conference "Passive and Low Energy Cooling for the Built Environment", May 2005, Santorini, Greece. Study of a new concept of photovoltaic-thermal hybrid collector. G. Fraisse, T. Lefebvre, Y.B. Assoa, C. Menezo and R. Yezou. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V50-4NPHJKC-1&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=fa8dd4b3c34444226a61e25695c261e1
5mjmp 20:17, 12 June 2009 (UTC)
Hybrid photovoltaic and thermal solar-collector designed for natural circulation of water 2006[edit | edit source]
This article is about a pc-silicon PV module on a flat-box type aluminum alloy thermal absorber using water as the collant adn it was built and tested. It was found to have a total efficiency of 40% and that it could achieve the desired water tank temperature in one day of exposure. The electrical efficiency was on average 9.87% which was lower than expected of 14.5%. It was determined that the use of water as a collant is most suitable for warm/hot climates.
In this article the MPPT (maximum power point tracker) is more efficient than nothing.
Metal strips on PV panel reflect light and need to be improved. This is why don't have intense grid on PV...
5mjmp 15:21, 7 September 2009 (UTC)
09_06_16_Hybrid photovoltaic and thermal solar-collector designed for natural circulation of water http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V1T-4GCWYPT-7&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=83b87287f0bb87d60889815d182d5698 5mjmp 18:59, 16 June 2009 (UTC)
Hybrid PV/T solar systems for domestic hot water and electricity production 2006[edit | edit source]
Energy Conversion and Management 47 (2006) 3368–3382. Hybrid PV/T solar systems for domestic hot water and electricity production. S.A. Kalogirou and Y. Tripanagnostopoulos. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V2P-4JJ2BCK-1&_user=1025668&_coverDate=11%2F30%2F2006&_alid=1014162511&_rdoc=5&_fmt=high&_orig=search&_cdi=5708&_sort=r&_st=5&_docanchor=&_ct=20&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=34c295e2fc144299f553050ada46da1d
5mjmp 17:48, 16 September 2009 (UTC) 09_09_16_Hybrid PVT solar systems for domestic hot water and electricity production.pdf
Double-Pass Photovoltaic-Thermal Solar Air Collector with Compound Parabolic Concentrator and Fins 2006[edit | edit source]
In this article, the combined efficiency achieved was ~70% when the mass flow rate was greater than 0.1 kg/s. In the experiments the light intenisty was varied from 400-700 W/ from 23 halogen lights rated at 500 W. "Temperature rise is proportional to the radiation intensity at a specific mass flow rate." It was found that the higher the flow rate the better the efficiency was, however, the system shoudl function with a low pressure drop. Therefore, this is an opmitmization problem between energy production and maintaining a low pressure drop.
Double-Pass Photovoltaic-Thermal Solar Air Collector with Compound Parabolic Concentrator and Fins. M. Y. Othman, B. Yatim, K. Sopian, and M. N. A. Bakar. JOURNAL OF ENERGY ENGINEERING © ASCE / DECEMBER 2006. http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JLEED9000132000003000116000001&idtype=cvips&gifs=yes
5mjmp 19:33, 5 June 2009 (UTC)
Performance, Cost and Life-Cycle Assessment Study of Hybrid PVT-Air Solar Systems 2006[edit | edit source]
The paper is about the research into improving PVT/AIR systems based on low-cost modifications. Areas of research include; improved air heat extraction by circulating air, reducing the PV module temperature and insulating the back surfaces and edges to reduct heat losses. Several different systems (with or without the following) were analyzed; diffuse reflectors, tilt, glazed thin film metalic sheet, just PV and combinations of the above. The test was done for 6 month and 12 months. The PVT-thin film metal sheet with a diffuse reflector produced the best results and was not the most expensive system eirther coming in at 29100 Euros. The energy payback, cost payback and CO2 payback were calculated. The lowest environmnental impact was the PVT with glaze and the best economic choice is the PVT/ thin film metal sheet. Note, both have reflectors added.
Prog. Photovolt: Res. Appl. 2006; 14:65–76. Performance, Cost and Life-cycle Assessment Study of Hybrid PVT/AIR Solar Systems. Y. Tripanagnostopoulos1,y, M. Souliotis, R. Battisti and A. Corrado. http://www3.interscience.wiley.com/journal/111081755/abstract?CRETRY=1&SRETRY=0
5mjmp 18:12, 11 June 2009 (UTC)
Double-Pass Photovoltaic-Thermal Solar Collector 2006[edit | edit source]
In this experiement monocrystalline silicon cells were pasted on to the absorber plate with fins. It was found that the fill factor decrease as radiation intenisty increased with constant mass flow rate. The fill factor decreased from.48 to.27 when the light intensity increased from 400 to 700 W/. This experiment used halogen lights to create the light intensities. The theorectical calculations followed the same tread as the experimental results, however, the experiemental results produced slightly higher efficiencies for thermal but lower efficiencies for electrical.
JOURNAL OF ENERGY ENGINEERING © ASCE / DECEMBER 2006. Double-Pass Photovoltaic-Thermal Solar Collector. M. Y. Othman1, B. Yatim, K. Sopian, and M. N. A. Bakar. http://cedb.asce.org/cgi/WWWdisplay.cgi?0613063
5mjmp 20:23, 5 June 2009 (UTC)
Energy performance of water hybrid PVT collectors applied to combisystems of Direct Solar type 2007[edit | edit source]
This article is about comparing several PVT system set ups and comparing it to the traditional PV + T system. It was concluded that due to the system heating up, the the PV panels produced less electricity when in a PVT system. The PV modules would get over 100 C (as much as 135 C) and at this temperature, one can not use Ethylene Vinyl Acetate (EVA) due to high degradation. The solution was to use Amorphous silicon or use an uncovered PVT system. Further research is required.
5mjmp 13:58, 8 September 2009 (UTC)
09_06_16_Energy performance of water hybrid PVT collectors applied to combisystems of Direct Solar type
Solar Energy 81 (2007) 1426–1438. Energy performance of water hybrid PV/T collectors applied to combisystems of Direct Solar Floor type. G. Fraisse, C. Me´ne´zo and K. Johannes. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V50-4N4YTKF-1&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=3b4311f17640d872eacc96f6d0c7e591 5mjmp 18:59, 16 June 2009 (UTC)
Transient Mathematical Model of Both Side Single Pass Photovoltaic Thermal Air Collector 2007[edit | edit source]
"A number of theoretical as well as experimental studies have been made on (PV/T) systems with air and liquid as working fluid. Kern and Russell  are the first who give main concept of PV/T collector using water or air as the heat removal fluid. Hendrie and Raghuraman  have made a comparative experimental study on photovoltaic thermal collectors with liquid and air as working fluid. Raghuraman  presented numerical methods predicting the performance of liquid and air PV/T collector. Sopian et al.  have successfully demonstrated the improved performance of a steady state double pass collector over the single pass collector due to efficient cooling of the photovoltaic cell. Garg and Adhikari  reported the performance analysis of hybrid photovoltaic thermal collector with integrated compound parabolic concentrator (CPC) troughs; this case indicated that the total efficiency with CPC is higher than system without CPC. Zondag et al.  compared the efficiency of seven different design types of photovoltaic thermal collectors. Mohd.Y.Hj.Othman et al.  design a new model of double pass PV/T air collector with CPC and fins and they studied its performance over range of operating conditions." -paper
This paper explains the theorectical calculations for a single pass air PVT. It has a flow chart of how the FORTRAN code works and the equations it uses. The theorectical calculations state the higher the mass flow rate the better the electrical and thermal efficiency. The total efficiency ranged from 26.6 to 39.13% with mass flow rates of 0.0316 to 0.09 kg/s. These calculations have not been experimentally tested.
5mjmp 20:23, 1 June 2009 (UTC)
ARPN Journal of Engineering and Applied Sciences. VOL. 2, NO. 5, OCTOBER 2007. TRANSIENT MATHEMATICAL MODEL OF BOTH SIDE SINGLE PASS PHOTOVOLTAIC THERMAL AIR COLLECTOR. Ebrahim M. Ali Alfegi, Kamaruzzaman Sopian, Mohd Yusof Hj Othman and Baharudin Bin Yatim. http://www.arpnjournals.com/jeas/research_papers/rp_2007/jeas_1007_62.pdf
Solar Hybrid Photovoltaic-Thermal Electricity 2007[edit | edit source]
"Most of these system configurations were based on the conventional flat-plate collectors with solar cells pasted on the absorber. Tripangnostopoulos et al.  have presented a summary on the work conducted by several researchers in the past in respect of PVT systems. Most of the research work and applications conducted earlier in this field  are converging on two alternate solutions: the first one, which is the most effective one, is to recover heat through natural or forced (mechanized) ventilation inside the panels; the second one, in which the heat can be transferred to another medium, such as water. The potential for architectural integration of this technology is considerable high and allows realizing a solar building envelope that produces energy to consume directly at the site. Applications of photovoltaic in built environment and its financial viability has been discussed by Bazilian et al. ." - Paper
The TIS (Integrated Solar Roof) was a tested PVT at the Politecnico di Milano. This PVT could be used on a wall or roof a building. In 2001 the CRF (Fait Research Centre) invested to add a PVT to their south wall which was financed under National Tetti fotovoltaici (Photovoltaic Roff) Programme. The PVT produced a 19.5 kWp and air was used as the coolant. The airflow as up ot 9000 m3/h and the temperature reached up to 60 C. The electrical efficiency of this system was about 9-10% and the thermal efficiency was ~30%. It was estimated that the PVT wall total primary energy savings were 185 MWh which corresponds to a CO2 reduction of 36 tons.
©2007 IEEE. Solar Hybrid Photovoltaic-Thermal (PVT) Façade for Heating, Cooling and Electricity Generation. F. Butera, R.S. Adhikari, N. Aste, and R. Bracco. http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4272471
5mjmp 18:48, 12 June 2009 (UTC)
Design, Development and Performance Monitoring of a Photovoltaic-Thermal Air Collector 2007[edit | edit source]
Written:2007 The research and development was completed at the Politecnico di Milano. The PV/T is made of a rectangle; bottom up: insulation then absorber plate then air gap for the air flow and then a glass top with checkered placed PV cells. Dimensions are included in article.
- actual efficiency
- nominal efficiency (from lab testing STC)
- Temperature correction factor
- Optical correction factor
- Absorbtion correction factor
- Spectrum correction factor
Seven sunny days were tested from march to august and the results show that the thermal efficiency was 20-40% and the electrical efficicency was 9-10%. Sunday days were chosen since there was not a way to correct for direct and diffused sunlight in this test.
In this article, there are equations to calculate the thermal balance of the PV cells, Thermal equilibrium of the glass (part of the sandwich without PV cells inside), Thermal equilibrium in the air gap, Thermal equilibrium of the absorber plate, PV thermal–spectral actual efficiency, Average temperature of the air in the gap and Thermal exchange coefficients.
The model and prototype were compared in this article and they were very similar.
Renewable Energy 33 (2008) 914–927. Design, development and performance monitoring of a photovoltaic-thermal (PVT) air collector. Niccolo` Aste�, Giancarlo Chiesa and Francesco Verri. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V4S-4PNF2KF-1&_user=1025668&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050549&_version=1&_urlVersion=0&_userid=1025668&md5=e411ef7879484c1bd205547f3c1fb8ac
5mjmp 20:07, 2 June 2009 (UTC)