Micro-generation for UK Households: Thermodynamic and Related Analysis

Student thesis: Doctoral ThesisPhD


Micro- generation is the small-scale and localised provision of heat or electricity. Micro-generators have the potential to reduce greenhouse-gas emissions and enhance energy security by providing heat or electricity from either renewable sources, or via the more efficient use of fossil fuels. But this potential is often unquantified or unclear, and hence quantitative information is required concerning both the energetic performance of micro-generators and their ability to provide net reductions in carbon emissions. In the context of household energy provision in the UK, thermodynamic and related carbon analyses of three micro-generation technologies have been carried out. These studies contribute to the research of the SUPERGEN ‘Highly Distributed Power Systems’ Consortium, which has been addressing a broad range of issues regarding micro-generation. The technologies analysed here are a grid-tied micro-wind turbine (rotor diameter 1.7m, rated power 600 W at 12 m/s), a grid-tied solar photovoltaic array (15 m2, 2.1 kWp mono-crystalline silicon), and a solar hot-water system (2.8 m2 flat-plate collector, direct-feed system). Annual energy outputs were estimated and contextualised against the demands of representative UK households. The overall energy-resource and carbon savings provided by the micro-generators were assessed on the basis that they (partially) displace the established supply systems. Savings were then compared with the energy-resource and carbon ‘debts’ of the micro-generators to determine their net performance. The displaced energy or carbon payback periods of the micro-generators were estimated to be well within their estimated lifetimes: a maximum 2.5 years for the SHW system, 3.1 years for the micro-wind turbine installed in an ‘open’ environment, and 7.4 years for the solar PV system. After payback, net energy-resource and carbon savings accrue. This thesis thus demonstrates that, given appropriate UK installations, all three micro-generators can reduce carbon emissions and enhance energy security by reducing use of, and dependence upon, fossil fuels.
Date of Award1 Jun 2009
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorGeoff Hammond (Supervisor)


  • microgeneration
  • energy analysis
  • net carbon analysis
  • Net energy analysis
  • household energy use

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