Research and development in novel alternative renewable energy technology.

Abstract

Fossil fuels have become the main energy source for human after the Industrial Revolution. However, with ever-increasing energy consumption, they are not sustainable in terms of their finite reserves, pollutions to the environment and contributions to climate change. Driven by these problems, the EU and UK have together set a mutual objective to generate renewable energy as 20% of the total energy supply by 2020. This research project, fully funded by Future Energy Source Ltd, is a direct response to the needs of developing novel alternative renewable energy technologies. This project concerns about the research and development of a large scale flat plate solar collector (LSFPSC) with serpentine tubing that can be fully integrated into building envelops. The project work focuses on design improvements for increasing thermal performance, enhancing reliability and minimising costs of the LSFPSC. This is accomplished by employing a three-stage approach combining both experimental testing and simulation studies. An experimental facility was designed and built for testing the LSFPSC prototype with comprehensive monitoring equipment for collecting important data such as temperature and flow rates. The 1st stage experimental results and mathematical analyses showed that the unglazed LSFPSC prototype has an operating efficiency of 28.55%. In the 2nd stage, research was done to propose suitable improvements which were then tested experimentally. These improvements include changing the heat transfer mechanism between the absorber and the circulation system, enhancing the bond conductivity and minimising convective losses. The improved prototype showed increased operating efficiencies of 43.50% (unglazed configuration) and 46.07% (glazed configuration). In the 3rd stage, the experimental and analysis data from the 2nd stage were employed to design TRNSYS simulation that was used to simulate the LSFPSC’s performance using weather data from 36 different locations in 22 countries. The simulation results showed the LSFPSC is capable of producing mean useful output of 1.29 GJ/m2/year (glazed) and 1.00 GJ/m2/year (unglazed). Further economic evaluation showed the LSFPSC has much shorter payback period (2.4 to 6.5 years) than the typical commercial flat plate collectors (8 to 12 years) indicating that the LSFPSC is an economical solution for low/medium temperature applications.