PhD thesisThis study addresses the global technical challenges of resource depletion and climate change
by developing the first demonstration of incorporating smart energy storage (super-capacitors
and batteries) with bio-fuel micro-tri-generation (BMT-HEES) for domestic applications. The
developed system is capable of producing required heat, electricity and refrigeration from
renewable bio-fuels for an average British household usage, and dynamically regulating the
energy distribution within the system by using a novel energy storage system and a following
electric load (FEL) energy management method.
In this study, an extensive literature review has been carried out to investigate previous trigeneration
and hybrid energy storage systems with a particular focus on their features,
advantages and challenges which provide a basis for further improvements. The research
work started with a preliminary investigation to fully understand the dynamic characteristics
of lead acid batteries and super-capacitors used in combination to provide the desirable
electrical output. The test results suggested that the super capacitors performed better than
batteries in meeting transient electrical demands.
In order to develop a complete BMT-HEES system, computational modeling and simulation
was then conducted in the Dymola simulation environment, where the complete BMT-HEES
system with advanced operational strategies has been implemented followed by case studies.
System performance was assessed by evaluating key performance indicators including fuel
consumption, dynamic response of each power sources, operational durations and energy
efficiencies.
A full experimental setup of the proposed system was also developed. Experimental tests on
individual components and the BMT-HEES system as a whole have validated the
effectiveness of the developed methodologies and techniques. Specific case studies have
proved that the system can improve over the existing ones in terms of energy efficiency (with
47.86% improvement compared to one tri-generation system without HEES) and dynamic
response for selected days as reported in the case studies. Test results from both simulation
and physical experiments show that BMT-HEES can satisfy the fluctuating energy demands
faithfully and instantly with high system efficiency for domestic applications.
In addition, the predicted performance based on the developed methodologies has a good
agreement with actual measurements. The low error of each assessment indicator provides
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the confidence that the system models can predict the system performance with good
accuracy (all of the errors were within 3%).
The developed technologies in this study can help cut down the carbon footprint in domestic
environments, facilitate a shift towards an environment-friendly lifestyle, and in the long run,
improve the quality of human life. Moreover, the established system is flexible, scalable and
inter-connectable. That is, the system can incorporate other types of bio-fuels or other sources
of new and renewable energy (wind, solar, geothermal, biomass etc.), depending on the
availability of the energy and location of the system used. In addition to the small-scale
domestic environment, the physical system can be scaled up to be used in larger commercial
and industrial environments. It may be used as a stand-alone energy system or it can be interconnected
with neighboring energy systems or connected with the power grid as a distributed
generation set if there is a need (or a surplus) of generated electricity. Without doubt, this will
require further work on this inter-disciplinary topic as well as new innovations in the fields of
energy networks and smart grids