2026-09-23T02:03:25Zhttps://api.repository.cam.ac.uk/server/oai/requestoai:www.repository.cam.ac.uk:1810/3061342026-04-16T13:01:09Zcom_1810_213729com_1810_256065col_1810_219485
The role of end-use energy conversion efficiency as a climate mitigation tool
10.17863/CAM.53213
Paoli, Leonardo
0000000187678073
Cullen, Jonathan
Historically, conversion efficiency improvements have revolutionised the energy system, yet
to reach climate targets, the scientific community agrees that even higher levels of energy
efficiency improvement are required. When focusing on technical options there are two
classes of technologies: conversion devices and passive systems. This thesis explores the
role that the former can have in reducing energy demand with the aim of providing advice on
the prioritisation and differentiation of policy action among these devices. The analysis is
divided into three main chapters.
First, issues with data quality were identified a cause for the marginalisation of end-use
efficiency measures compared to supply-side ones. For the first time, the uncertainty of
end-use statistics is quantified by drawing from methods developed in the field of Material
Flow Analysis using the United Kingdom as a case study. The majority (85%) of the Useful
energy balance uncertainties are below an acceptable (±25%) threshold. Therefore, end-use
statistics are deemed sufficiently reliable for the development of policy-relevant indicators.
Second, the technical efficiency limits for six widely used conversion devices are determined
stochastically based on a combination of engineering models and review of the technical
literature. The resulting limits are used to calculate the energy saving potential of each
conversion device, and each design parameter for the United Kingdom. It is shown that 25%
of the UK’s Final energy demand could be avoided if all conversion devices reached their
technical limit. On the other hand, 15% savings could be achieved by applying available
technology. Nonetheless, improvement margins vary substantially among devices meaning
that strategies involving different balances of R&D and technology adoption incentives are
required for each technology.
Third, the International Energy Agency’s Energy Technology Perspective’s modelling results
are used to assess the saving potential of seven conversion devices in three emission scenarios.
Between 3.2% and 4.2% of cumulative energy demand between 2014 and 2060 can be saved thanks to improvements in conversion efficiency. Most savings come from improved internal
combustion engines in all scenarios. Carbon emission savings from conversion efficiency
are highest in the baseline scenario and lowest in the most ambitious climate scenario due
to negative emissions in electricity generation nullifying the effect of improvements in
electricity-using devices. No technology was found to breach the technical efficiency limit in
the IEA’s assessment meaning that expected efficiency improvements technically realistic.
Current innovation activity in energy conversion devices is quantified by means of patent
counts and it’s compared to the distribution of saving potentials. It is found that innovation
in air coolers and heat pumps is low when compared to the expected efficiency savings from
these technologies.
The thesis results are useful for directing policy and investment priorities for conversion devices
as function of the ambition of the climate scenario. The analysis of technical efficiency
limits for conversion devices, help improve energy system models. The novel uncertainty
method provides a powerful tool for supporting energy planning and decision making.
University of Cambridge
2019-09-28
Thesis
Doctoral
Doctor of Philosophy (PhD)
eng
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energy efficiency
climate change
energy statistics
uncertainty