High Performance Vacuum Flat Plate Solar Thermal Collectors for Hot Water and Process Heat

Lead Research Organisation: University of Warwick
Department Name: Sch of Engineering

Abstract

The aim of the proposed research is to provide the necessary knowledge to allow the development of a pre-prototype High Performance Vacuum Flat Plate Solar Thermal Collector with minimal materials content. The development of a thin evacuated solar collector offers new and exciting prospects for integrating solar collectors into building designs and for their use in medium temperature (100-200 Celsius) applications such as air conditioning or low temperature process heat. The research planned will develop technology for the effective utilisation of the solar energy resource and fits within EPSRC's Energy theme. Solar thermal energy is predicted to be a significant growth market with the potential to make a significant contribution to reducing fossil fuel use in the building energy sector. The research is targeted at providing new knowledge and techniques that will enable the advances in technology necessary for a step change in solar thermal collector performance to be realised and a range of new products and application areas developed. Such new products will encourage inward investment and lead to the creation of new companies that can contribute significantly to the transition to a low carbon society whilst maintaining and improving quality of life.

Planned Impact

The proposed research will provide the necessary knowledge to allow the development of a pre-prototype High Performance Vacuum Flat Plate Solar Thermal Collector with minimal materials content. The development of a thin evacuated solar collector offers new and exciting prospects for integrating solar collectors into building designs and for their use in medium temperature (100-200 Celsius) applications such as air conditioning or low temperature process heat.

A 2008 UK survey found that each household consumes on average 122 litres of hot water each day. In 2009, hot water accounted for 18% of all delivered energy consumed in the domestic sector. A growth in the UK solar thermal market is predicted as a result of the target set by DEFRA in 2008 of reducing the energy use for conventional domestic heating and hot water systems. Solar thermal heating for domestic hot water is the fastest growing renewable technology across Europe; the UK solar thermal market grew by 24% to £25M in 2010. This project is particularly timely as a renewable heat incentive tariff is planned for implementation in the UK in summer 2013. The scheme is intended to increase the contribution of renewable heat generation technologies from 1.5% (in 2011) to a level of 12% by 2020. The research planned will develop technology for the effective utilisation of the solar energy resource and fits within EPSRC's Energy theme. Solar thermal energy is predicted to be a significant growth market with the potential to make a significant contribution to reducing fossil fuel use in the building energy sector.

Across Europe, there is clear interest in and demand for technology that allows production of low and medium temperature heat from systems that are simple to install, have good aesthetics and can be adapted for effective building integration. Low temperature process heat constituted over 30% of UK industrial energy use in 2009. Advanced solar thermal systems have a huge potential market both in the UK and overseas and can play a significant part in meeting our CO2 emission reduction targets both in the near term and to 2050. This project will build on current UK world leading research into technology for vacuum glazing and develop a new research area in solar energy that will be crucial to our transition to a low carbon society. The planned research is targeted at providing new knowledge and techniques that will enable the advances in technology necessary for a step change in solar thermal collector performance to be realised and a range of new products and application areas developed. Such new products will encourage inward investment and lead to the creation of new companies that can contribute significantly to the transition to a low carbon society whilst maintaining and improving quality of life.

Publications

10 25 50
 
Description Vacuum enclosures suitable for flat plate absorber solar collectors have been designed with systems fabricated and characterised.
Progress was in accordance with the original workplan.
Detailed analysis of absorber design, heat transfer and stress were performed both theoretically and experimentally.
The key issues associated with achieving excellent long term performance have been identified.
Exploitation Route The Vacuum flat plate solar collector systems require further research and development to improve long term durability and optimise performance for different applications prior to having a system that can be commercialised.
The compact thin nature of the prototypes will make them suitable for building facade integration. The high optical and thermal efficiency and high temperatures possible make vacuum flat plate solar collectors suitable for combination with solar cooling systems and potentially thermochemical heat storage systems.
Sectors Energy

 
Description The prototype systems developed have been used to demonstrate to MSc students the potential of improving solar thermal system performance for climates similar to the UK and that thin planer solar thermal system suitable for building envelope integration are possible. PhD students and RAs have incorporated vacuum flat plate performance data generated from the project into models to predict the feasibility and efficiency of charging thermochemical heat storage systems for inter-seasonal heat storage for space heating, and phase change heat storage systems for daily hot water provision. In subsequent research an array of compound parabolic concentrators with selectively coated tubular absorbers was successfully enclosed within a thin planer vacuum panel system achieving low rates of heat losses, the ability to concentrate both direct and a significant fraction of the diffuse solar radiation within the collector acceptance angle and to achieve higher operational temperatures with good efficiency.
First Year Of Impact 2020
Sector Education,Energy
Impact Types Societal

 
Description Cranfield Solar thermal workshop 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Talk given to industry professionals which prompted discussion and further collaboration on coating technologies.
Year(s) Of Engagement Activity 2015
URL http://www.ultraprecision.org/news/events/uk-solar-thermal-manufacturing/
 
Description SolarFest 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact On 22nd September 2017, SolarFest brought around 165 school children and families from around the area to the Warwick campus to learn about the science of the sun through interactive displays, workshops and encounters with University of Warwick researchers. Not only did they go away with new knowledge about the sun as our nearest star and an incredible source of energy, they also saw how research conducted within universities is advancing our understanding of the universe and driving new technologies. Through meeting with researchers from diverse backgrounds and identities, they were all encouraged to think of themselves as the next generation of scientists and innovators.
Year(s) Of Engagement Activity 2017
URL https://warwick.ac.uk/research/priorities/energy/news/solarfest/
 
Description Sustainble Thermal Energy Technologies for the Future 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Support for Innovation and Growth from the universities, a Conference for Industry on Sustainable Thermal Energy Technologies for the Future - with keynote contributions from Delta-ee, the Industrial and Commercial Energy Association (ICOM), the Heating and Hotwater Industry Council (HHIC), Baxi, National Grid and the Knowledge Transfer Network, and more.
Key topics:
? Policy and future energy scenarios
? The future - what does industry need to deliver
sustainable, secure and low carbon heating and cooling for homes and business?
? Funding of research and development to support growth, innovation and the development of new products and services
? Future technologies - how can the universities support the needs of industry?
The conference presented an opportunity for networking with policy makers, senior representatives from the energy sector and researchers from the universities.
There was a tour of the Sustainable Thermal Energy Technologies Laboratory at the University of Warwick where new heating and cooling technologies are being developed. The facilities include our large scale solar simulator for solar module testing.
Year(s) Of Engagement Activity 2016
URL http://www2.warwick.ac.uk/newsandevents/events/thermal/
 
Description Warwick solar energy systems workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact A collaborative workshop in partnership between the University of Warwick, Freeths and the Knowledge Transfer Network (KTN) that aims to highlight current and future possibilities for engaging solar energy research and industry through innovation partnerships and projects.
Warwick's research team were contracted to carry out testing for 3 companies.
A link was made with Cranfield University and another talk was subsequently given at an event in Cranfield.
Year(s) Of Engagement Activity 2015
URL http://www2.warwick.ac.uk/newsandevents/events/solarenergy/