The concept of an evacuated flat plate collector was proposed over 40 years ago but, despite its professed advantages, very few manufacturers have developed commercial versions. This paper demonstrates the reduction in heat loss coefficient and increase in efficiency resulting from evacuating a flat plate collector: it is hoped that these results will stimulate interest in the concept. Evacuated tubes are now mass-produced in large numbers; evacuated flat plate collectors could in principle replace these tubes if the technical difficulties in creating extended metal-glass seals can be overcome. The experimental experiences described here should indicate targets for future research.Two different designs of evacuated flat plate solar thermal collector, each with a 0.5×0.5m flooded panel black chrome plated absorber, were tested under a solar simulator. The cover glasses were supported by an array of 6mm diameter pillars. Inlet and outlet temperatures were monitored via PT100 RTDs and glass temperatures were measured using thermocouples. Inlet temperature was controlled by a fluid circulator connected to a header tank with a Coriolis mass flow meter to measure fluid flow rate. Testing was conducted indoors with and without the use of a fan to cool the top cover glass. The test conditions spanned the range 200
Bibliographical noteReference text: Abbate, P., 2012. Presentation on the TVP evacuated panel at InterSolar, https://www.
youtube.com/watch?v=z_4FD4Zxwew (Accessed 12/7/2017).
Alam, M., Singh, H., Suresh, S., Redpath, D.A.G., 2017. Energy and economic analysis of
Vacuum Insulation Panels (VIPs) used in non-domestic buildings. Appl. Energy
Alobaid, M., Hughes, B., Calautit, J.K., O’Connor, D., Heyes, A., 2017. A review of solar
driven absorption cooling with photovoltaic thermal systems. Renew. Sustain. Energy
Rev. 76, 728–742.
Beikircher, T., Goldemund, G., Benz, N., 1996. Gas heat conduction in an evacuated tube
solar collector. Sol. Energy 58 (4–6), 213–217.
Beikircher, T., Möckl, M., Osgyan, P., Streib, G., 2015. Advanced solar flat plate collectors
with full area absorber, front side film and rear side vacuum superinsulation. Sol.
Energy Mater. Sol. Cells 141, 308–406.
Benvenuti, C., Ruzinov, V., 2010. The SRB evacuated flat solar panel, Proceedings of
ECOS, pp. 2–429 to 434, http://infoscience.epfl.ch/record/165003/files/Ecos2010-
Benvenuti, C., 2013a. The SRB solar thermal panel. Europhys News 16–18. http://dx.doi.
Benvenuti, C., 2013b. Particle accelerators and solar panels. Fisica E 29 (1–2), 31–38.
Benz, N., Beikircher, T., 1999. High efficiency evacuated flat-plate solar collector for
process steam production. Sol. Energy 65 (2), 111–118.
Bouvier, J.-L., Michaux, G., Salagnac, P., Kientz, T., Rochier, D., 2016. Experimental study
of a micro combined heat and power system with a solar parabolic trough collector
coupled to a steam Rankine cycle expander. Sol. Energy 134, 180–192.
Brunold, S., Frey, R., Frei, U., A comparison of three different collectors for process heat
applications. SPF publication. http://spf.ch/fileadmin/daten/publ/procheat.pdf.
Buttinger, F., Beikircher, T., Proll, M., Scholkopf, W., 2010. Development of a new flat
stationary evacuated CPC-collect or for process heat applications. Sol. Energy 84,
Caër, V.H.-L., De Chambriera, E., Mertina, S., Jolya, M., Schaerb, M., Scartezzinia, J.-L.,
2013. Optical and morphological characterisation of low refractive index materials
for coatings on solar collector glazing. Renew. Energy 53, 27–34.
Colangelo, G., Favale, E., Miglietta, P., de Risi, A., 2016. Innovation in flat solar thermal
collectors: A review of the last ten years experimental results. Renew. Sustain. Energy
Rev. 57, 1141–1159.
Collins, R.E., Turner, G.M., Fischer-Cripps, A.C., Tang, J.Z., Simko, T.M., Dey, C.J.,
Clugston, D.A., Zhang, Q.C., Garrison, J.D., 1995. Vacuum glazing – a new component
for insulating windows. Build. Environ. 30 (4), 459–492.
Ehrmann, N., Reineke-Koch, R., 2012. Selectively coated high efficiency glazing for solarthermal
flat-plate collectors. Thin Solid Films 520, 4214–4218.
ETSAP, 2015. Solar Heat for Industrial Processes (IEA-ETSAP and IRENA Technology
Brief E21), http://www.irena.org/DocumentDownloads/Publications/IRENA_
Freeman, J., Hellgardt, K., Markides, C.N., 2015. An assessment of solar-thermal collector
designs for small-scale combined heating and power applications in the United
Kingdom. Heat Transfer Eng. 36 (14–15). http://dx.doi.org/10.1080/01457632.
Gao, X.-H., Theiss, W., Shen, Y.-Q., Ma, P.-J., Liu, G., 2017. Optical simulation, corrosion
behavior and long term thermal stability of TiC-based spectrally selective solar absorbers.
Sol. Energy Mater. Sol. Cells 167, 150–156.
Helsch, G., Deubener, J., 2012. Compatibility of antireflective coatings on glass for solar
applications with photocatalytic properties. Sol. Energy 86, 831–836.
Henshall, P., Moss, R., Arya, F., Eames, P.C, Shires, S., Hyde, T., 2014. An evacuated
enclosure design for solar thermal energy applications. Grand Renewable Energy
2014 (GRE2014) International Conference and Exhibition, Tokyo, Japan, 27 July – 1
August 2014, https://dspace.lboro.ac.uk/2134/16098.
Henshall, P., Eames, P., Arya, F., Hyde, T., Moss, R., Shire, S., 2016. Constant temperature
induced stresses in evacuated enclosures for high performance flat plate solar thermal
collectors. Sol. Energy 127, 250–261.
Incropera, F.P., DeWitt, D.P., 2002. Introduction to Heat Transfer, fourth ed. Wiley.
Joly, M., Antonetti, Y., Python, M., Gonzalez, M., Gascou, T., Scartezzini, J.-L., Schuler,
A., 2013. Novel black selective coating for tubular solar absorbers based on a sol–gel
method. Sol. Energy 94, 233–239.
Kalogirou, S.A., 2014. Solar Energy Engineering, second ed. Academic Press.
Kennedy, C.E., 2002. Review of mid- to high-temperature solar selective absorber materials
Leone, G., Beccali, M., 2016. Use of finite element models for estimating thermal performance
of façade-integrated solar thermal collectors. Appl. Energy 171, 392–404.
Lira-Cantú, M., Sabio, A.M., Brustenga, A., Gómez-Romero, P., 2005. Electrochemical
deposition of black nickel solar absorber coatings on stainless steel AISI316L for
thermal solar cells. Sol. Energy Mater. Sol. Cells 87, 685–694.
Lizama-Tzec, F.I., Macías, J.D., Estrella-Gutiérrez, M.A., Cahue-López, A.C., Arés, O., de
Coss, R., Alvarado-Gil, J.J., Oskam, G., 2015. Electrodeposition and characterization
of nanostructured black nickel selective absorber coatings for solar–thermal energy
conversion. J. Mater. Sci.: Mater. Electron. 26, 5553–5561. http://dx.doi.org/10.
Martın, R.H., Perez-Garcıa, J., Garcıa-Soto, F.J., Lopez-Galiana, E., 2011. Simulation of an
enhanced flat-plate solar liquid collector with wire-coil insert devices. Sol. Energy 85,
McDonald, G.E., 1975. Spectral reflectance properties of black chrome for use as a solar
selective coating. Sol. Energy 17, 119–122.
Moss, R., Shire, S., 2014. Design and performance of evacuated solar collector microchannel
plates. In: Conference Proceedings: EuroSun 2014, Aix-les-Bains (France),
16–19 September 2014, http://proceedings.ises.org/paper/eurosun2014/
Moss, R.W., Shire, G.S.F., Henshall, P., Eames, P.C., Arya, F., Hyde, T., 2017. Optimal
passage size for solar collector micro-channel and tube-on-plate absorbers. Sol.
Energy 153, 718–731. http://dx.doi.org/10.1016/j.solener.2017.05.030.
Moss, R.W., Henshall, P., Arya, F., Shire, G.S.F., Hyde, T., Eames, P.C., 2018a.
Performance and operational effectiveness of evacuated flat plate solar collectors
compared with conventional thermal, PVT and PV panels. Appl. Energy 216,
Moss, R.W., Shire, G.S.F., Henshall, P., Eames, P.C., Arya, F., Hyde, T., 2018b. Design and
fabrication of a hydro-formed absorber for an evacuated solar collector. Appl. Therm.
Moss, R.W., Shire, G.S.F., Eames, P.C., Henshall, P., Hyde, T., Arya, F., 2018c. Design and
commissioning of a virtual image solar simulator for testing thermal collectors. Sol.
Energy 159, 234–242. http://dx.doi.org/10.1016/j.solener.2017.10.044.
Nkwetta, D.N., Smythe, M., 2012. The potential applications and advantages of powering
solar air-conditioning systems using concentrator augmented solar collectors. Appl.
Energy 89, 380–386.
O’Hegarty, R., Kinnane, O., McCormack, S.J., 2017. Concrete solar collectors for façade
integration: An experimental and numerical investigation. Appl. Energy 206,
Purohit, I., Purohit, P., 2017. Technical and economic potential of concentrating solar
thermal power generation in India. Renew. Sustain. Energy Rev. 78, 648–666.
Riggs, B.C., Biedenharn, R., Dougher, C., Ji, Y.V., Xu, Q., Romanin, V., Codd, D.S., Zahler,
J.M., Escarra, M.D., 2017. Techno-economic analysis of hybrid PV/T systems for
process heat using electricity to subsidize the cost of heat. Appl. Energy 208,
Selvakumar, N., Barshilia, H.C., 2012. Review of physical vapor deposited (PVD) spectrally
selective coatings for mid- and high-temperature solar thermal applications.
Sol. Energy Mater. Sol. Cells 98, 1–23.
Sharma, N., Diaz, G., 2011. Performance model of a novel evacuated-tube solar collector
based on minichannels. Sol. Energy 85, 881–890.
SPF catalogue of solar collector test results http://www.spf.ch/index.php?id=111&L=6
accessed August 2017.
TVP Solar, MT-30 datasheet, http://www.tvpsolar.com/files/pagine/1464011780_MTPower%
20Datasheet%20(v4.2x)(ver5).pdf (Accessed 12/7/2017).
Suman, S., Khan, M.K., Pathak, M., 2015. Performance enhancement of solar collectors –
a review. Renew. Sustain. Energy Rev. 49, 192–210.
Simko, T.M., Fischer-Crips, A.C., Collins, R.E., 1998. Temperature-induced stresses in
vacuum-glazing: modelling and experimental validation. Sol. Energy 63 (1), 1–21.
Zambolin, E., Col, D.D., 2010. Experimental analysis of thermal performance of flat plate
and evacuated tube solar collectors in stationary standard and daily conditions. Sol.
Energy 84, 1382–1396.
- Flat plate