{"id":311,"date":"2018-11-06T09:53:21","date_gmt":"2018-11-06T09:53:21","guid":{"rendered":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/?p=311"},"modified":"2018-12-05T15:35:12","modified_gmt":"2018-12-05T15:35:12","slug":"one-stone-two-bird-synergies-next-generation-solar-technologies","status":"publish","type":"post","link":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/2018\/11\/06\/one-stone-two-bird-synergies-next-generation-solar-technologies\/","title":{"rendered":"One-Stone, Two-Bird Synergies: Next-generation solar technologies"},"content":{"rendered":"

The solar sector is experiencing by far the highest global growth and new investment in renewable technologies. Solar energy is the world\u2019s most abundant permanent energy source: one hour of solar radiation is equivalent to more than the world\u2019s total\u00a0annual energy need. It is projected that solar energy will cover one-third of the world\u2019s energy consumption by 2060 under favourable conditions. Solar energy can be converted into other energy forms that are\u00a0useful in sustaining society; in particular, it can be converted to electricity by solar photovoltaic (PV) systems or into thermal energy by solar-thermal (ST) systems.<\/strong><\/p>\n

Christos Markides, Professor of Clean Energy Technologies at the Department of Chemical Engineering, Imperial College London and Head of the Clean Energy Processes (CEP) Laboratory, recently won the Institution of Chemical Engineers (IChemE) Global Award for Best Research Project for the lab\u2019s work developing a promising emerging hybrid PV-T\u00a0solar-energy technology, which synergistically\u00a0integrates\u00a0PV and ST technologies, and is capable of delivering both electricity and heat.<\/strong><\/p>\n

<\/p>\n

The CEP Laboratory has been active in researching hybrid solar-energy systems by considering solutions for improving the performance and reducing the costs of such technologies, as well as developing advanced thermodynamic, economic and environmental models to assess their potential for use in a variety of applications. In this article he explains how the technology works, and presents the state-of-the-art and future\u00a0research that is\u00a0ongoing in the\u00a0CEP\u00a0Laboratory and beyond,\u00a0aimed at\u00a0advancing this\u00a0technology.<\/strong><\/p>\n

\n

PV panels are the best-known technology for generating renewable electricity based on the conversion of sunlight into\u00a0electricity by a variety of semiconductor materials. In\u00a0this conversion process,\u00a0only about 15% of the absorbed sunlight is converted to useful electricity, while the rest is partially stored as heat and ultimately lost to the environment. The accumulated heat causes the temperature\u00a0of the panels to rise, with temperatures reaching up to 60-80\u00b0C on hot days, leading to a decrease in their efficiency and overall lifetime.<\/p>\n

\"\"
Solar panels are one of the most recognisable forms of solar photovoltaic systems<\/figcaption><\/figure>\n

In contrast to PV systems where heat is an unfavourable by-product, ST systems aim to\u00a0deliver useful heat by effectively absorbing solar energy at a much higher efficiency and transferring this to a\u00a0stream of\u00a0air, water or another fluid. You may have used a traditional immersion heater, where water is heated and stored until it\u2019s needed, perhaps for a shower or for washing up. ST systems work similarly, except the water is heated by solar energy.<\/p>\n

ST heating has the potential to make a significant impact in transforming the renewable energy landscape, given that half of the global energy demand is used for heating purposes: hot water for cooking and washing, central heating, and industrial and manufacturing processes. Harnessing a renewable source of primary energy to provide this heat, reduces the consumption of fossil fuels, reduces emissions and the impact on the environment.<\/p>\n

Hybrid PV-T systems combine PV and ST technologies, allowing for electrical and thermal outputs to be obtained simultaneously from the same installed area, and reducing the losses in the electrical efficiency of solar panels caused by excessive operating temperatures.<\/p>\n

This is achieved by using a cooling flow of either air or water through or over the PV module, which can lower the temperature of the equipment whilst producing a hot stream of air of water as a thermal output that can be used for hot-water provision, space heating or cooling. Hybrid PV-T technology provides a particularly promising energy solution when roof space is limited, at a premium or when heat and electricity are required at the same time.<\/p>\n

\"\"<\/a>
Solar-Thermal and Hybrid Photovoltaic-Thermal Systems for Renewable Heating from Grantham Institute Briefing Paper, page 14.<\/figcaption><\/figure>\n

Results from both experimental tests and models developed by the CEP Laboratory suggest that with an appropriate installation area and operation strategy, hybrid PV-T systems are capable of\u00a0significantly reducing fossil-fuel consumption for power, heating and\/or cooling provision in residential or commercial buildings. The decarbonisation potential of hybrid systems exceeds that of singular systems, either in use on their own or side-by-side, and the cost of energy is competitive or even lower than stand-alone systems in optimal conditions.<\/p>\n

In recent work funded by EPSRC<\/a>, the CEP group has proposed a roadmap for next-generation PV-T technology capable of delivering electricity more efficiently while simultaneously providing higher-grade heat, broadening the applications for this sustainable, low-carbon technology. CEP researchers have identified systematic strategies for reducing the thermal and electrical losses that can lead to hybrid systems with a 70% improvement in thermal efficiency and a 20% improvement in carbon savings and financial payback compared to present commercial collectors.<\/p>\n

Led by CEP group\u00a0member\u00a0Dr Kai Wang, the team is now developing novel PV-T collector designs based on an innovative principle in which the solar\u00a0spectrum is split\u00a0into\u00a0separate portions, one that is well-suited to conversion into electricity and that is\u00a0directed directly\u00a0to the\u00a0PV cells, and a second that is\u00a0absorbed as thermal energy. This decoupling of the\u00a0thermal and electrical elements of the collector\u00a0reduces the PV cell temperatures and\u00a0allows higher electrical conversion efficiencies, while at the same time\u00a0supplying a thermal output at temperatures considerably higher than the PV operation temperature. Novel\u00a0materials and fluids are being developed and tested to identify optimal\u00a0designs.<\/p>\n

The group believes that\u00a0innovations such as these can unlock the potential of\u00a0PV-T technology by\u00a0allowing\u00a0step-changes in\u00a0performance\u00a0and\u00a0cost\u00a0competitiveness,\u00a0and promoting but also\u00a0enabling further application possibilities. A recent Imperial College\u00a0spin-out company, Solar\u00a0Flow Limited<\/a>, has been founded to further develop and\u00a0commercialise the technology \u2013 for further\u00a0information, please contact: c.markides@imperial.ac.uk<\/u><\/a>.<\/p>\n

 <\/p>\n

References:<\/strong><\/p>\n

    \n
  1. Roadmap for the next-generation of hybrid photovoltaic-thermal solar energy collectors\u00a0<\/em>in\u00a0Solar Energy\u00a0<\/strong>(https:\/\/doi.org\/10.1016\/j.solener.2018.09.004<\/u><\/a>).<\/li>\n
  2. Solar-Thermal and Hybrid Photovoltaic-Thermal Systems for Renewable Heating\u00a0<\/em>in\u00a0Grantham Institute Briefing Paper Publications\u00a0<\/strong>(https:\/\/www.imperial.ac.uk\/media\/imperial-college\/grantham-institute\/public\/publications\/briefing-papers\/2679_Briefing-P-22-Solar-heat_web.pdf<\/u><\/a>).<\/li>\n
  3. Technoeconomic modelling and optimisation of solar combined heat and power systems based on flat-box PVT collectors for domestic applications\u00a0<\/em>in\u00a0Energy Conversion and Management\u00a0<\/strong>(https:\/\/doi.org\/10.1016\/j.enconman.2018.07.045<\/u><\/a>).<\/li>\n
  4. Thermoeconomic assessment of a PV\/T combined heating and power system for University Sport Centre of Bari\u00a0<\/em>in\u00a0Energy Procedia\u00a0<\/strong>(https:\/\/www.researchgate.net\/publication\/327285663_Thermoeconomic_assessment_of_a_PVT_combined_heating_and_power_system_for_University_Sport_Centre_of_Bari<\/u><\/a>).<\/li>\n
  5. Thermodynamic and Economic Assessments of a Hybrid PVT-ORC Combined Heating and Power System for Swimming Pools\u00a0<\/em>in\u00a0Heat Powered Cycles Conference Proceedings\u00a02018\u00a0<\/strong>(https:\/\/www.researchgate.net\/publication\/327285587_Thermodynamic_and_Economic_Assessments_of_a_Hybrid_PVT-ORC_Combined_Heating_and_Power_System_for_Swimming_Pools<\/u><\/a>).<\/li>\n
  6. Hybrid photovoltaic-thermal solar systems for combined heating, cooling and power provision in the urban environment\u00a0<\/em>in\u00a0Energy Conversion and Management\u00a0<\/strong>(https:\/\/doi.org\/10.1016\/j.enconman.2017.03.024<\/u><\/a>).<\/li>\n
  7. A UK-based assessment of hybrid PV and solar-thermal systems for domestic heating and power: System performance\u00a0<\/em>in\u00a0Applied Energy\u00a0<\/strong>(https:\/\/doi.org\/10.1016\/j.apenergy.2014.01.061<\/u><\/a>).<\/li>\n
  8. Hybrid PV and solar-thermal systems for domestic heat and power provision in the UK: Techno-economic considerations\u00a0<\/em>in\u00a0Applied Energy\u00a0<\/strong>(https:\/\/doi.org\/10.1016\/j.apenergy.2015.09.025<\/u><\/a>).<\/li>\n
  9. Dynamic coupled thermal-and-electrical modelling of sheet-and-tube hybrid photovoltaic\/thermal (PVT) collectors\u00a0<\/em>in\u00a0Applied Thermal Engineering\u00a0<\/strong>(https:\/\/doi.org\/10.1016\/j.applthermaleng.2016.02.056<\/u><\/a>).<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"

    The solar sector is experiencing by far the highest global growth and new investment in renewable technologies. Solar energy is the world\u2019s most abundant permanent energy source: one hour of solar radiation is equivalent to more than the world\u2019s total\u00a0annual energy need. It is projected that solar energy will cover one-third of the world\u2019s energy […]<\/p>\n","protected":false},"author":1225,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[294272,81],"tags":[13021,365,294274,294273],"class_list":["post-311","post","type-post","status-publish","format-standard","hentry","category-clean-energy","category-research","tag-emissions","tag-energy","tag-renewables","tag-solar"],"_links":{"self":[{"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/posts\/311","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/users\/1225"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/comments?post=311"}],"version-history":[{"count":9,"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/posts\/311\/revisions"}],"predecessor-version":[{"id":340,"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/posts\/311\/revisions\/340"}],"wp:attachment":[{"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/media?parent=311"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/categories?post=311"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs-staging.imperial.ac.uk\/chemical-engineering\/wp-json\/wp\/v2\/tags?post=311"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}