THE POTENTIAL IMPACTS OF MICRO- GENERATION AND LOW-CARBON HEATING ON DISTRIBUTION NETWORKS Owain Jones A thesis submitted for the degree of Master of Philosophy University College London March 2018 1 DECLARATION I, Owain Jones, confirm that the work presented in this thesis is my own. Where information has been derived from other sources, I confirm that this has been indicated in the thesis. 2 ABSTRACT Micro-generation and low-carbon heat could potentially form part of the UK's decarbonisation strategy. This study examines the potential impacts of micro-CHP, solar PV and air-source heat pumps on distribution networks, using minute-scale electricity generation and demand data from field studies. These data are augmented by simulated data for a fuel cell micro-CHP profile, based on the heat demand of an average UK household. The value of using minute-scale rather than lower frequency data is more accurate information on peaks in household demand. An analysis of the economic implications of micro-CHP concludes that micro-CHP would have to fall in price for it to be economically viable for the household. Moreover, emissions benefits are limited and prone to decline. The supply and demand profiles of the various technologies were used with network design software (IPSA-Power), and models of real world distribution networks, to understand their potential impacts on distribution networks. Two sub-urban networks were analysed, with similar results, indicating the results can be generalised. For each minute of data, a steady state load flow analysis was performed in order to approximate a dynamic power system analysis. Stirling engine micro-CHP has only minor impacts on the distribution network, principally through reducing power losses. Fuel cell micro-CHP can have considerable benefits through reducing losses and power flows, however one more than 60% of homes install fuel cell micro-CHP these benefits will be reduced. The other technologies tend to have greater detrimental impacts on networks through less frequent but greater voltage rise (solar PV), increased power flows (heat pumps) and increased losses (both solar PV and heat pumps). Micro-CHP can worsen the effects of solar PV and mitigate the effects of heat pumps if the technologies are deployed on the same network. 3 DEDICATION This thesis is dedicated to my parents, for encouraging my curiosity and bookishness, and for all the support they have given me through the years. 5 ACKNOWLEDGEMENTS I would first like to thank my supervisors, Paul Dodds and Paul Ekins, for their support. They have been there to provide me with advice and guidance throughout the process, and have provided me with much useful feedback on drafts of my thesis. As well as introducing me to contacts, and helping me to find useful data. The thesis would not have been possible without the aid of colleagues at Durham University and Northern Powergrid, especially Robin Wardle and Peter Matthews. I spent three months at Durham University working with data from the CLNR project, which I was subsequently able to use in my thesis. Robin introduced me to, and provided me with guidance on, network modelling software, without which I could not have conducted much of the research in this thesis. They also provided me with the network models used within this thesis. I would also like to thank TNEI for providing the IPSA-Power software, and for the training courses that they run on how to use it, both of which were of great aid to this thesis. I would like to thank E.On for providing funding for this research. Finally, I would like to thank my parents for providing me with support (and accommodation) through the final stages of this study. 7 CONTENTS 1 Introduction ..................................................................................... 23 1.1 Background of micro-CHP ........................................................................ 24 1.1.1 Stirling engines .............................................................................. 24 1.1.2 Internal Combustion Engines ........................................................ 25 1.1.3 Fuel cell micro-CHP ...................................................................... 26 1.2 Other micro-generation or low-carbon heat technologies .......................... 29 1.2.1 Solar PV ......................................................................................... 29 1.2.2 Heat pumps .................................................................................... 29 1.3 Electricity distribution networks ................................................................ 29 1.4 Research questions ..................................................................................... 30 1.5 Novel contribution of this study................................................................. 32 1.6 Thesis Outline ............................................................................................ 33 2 Literature Review ........................................................................... 35 2.1 Fuel sources for micro-CHP and its contributions to decarbonisation ...... 35 2.1.1 Natural Gas .................................................................................... 35 2.1.2 Bioenergy ....................................................................................... 37 2.1.3 Hydrogen ....................................................................................... 38 2.1.4 Areas of uncertainty ....................................................................... 39 2.2 Economics of micro-CHP .......................................................................... 39 2.2.1 Broad factors affecting the economics and expected energy cost savings of micro-CHP .................................................................... 39 2.2.2 Current and future costs of micro-CHP ......................................... 41 2.2.3 Areas of uncertainty ....................................................................... 43 9 2.3 Other low-carbon heating and micro-generation options .......................... 43 2.3.1 Heat Pumps .................................................................................... 43 2.3.2 Solar PV ......................................................................................... 44 2.4 Challenges and opportunities facing electricity networks ......................... 44 2.4.1 The challenge of electrifying heat provision ................................. 45 2.4.2 Advantages and issues of micro-CHP ........................................... 46 2.4.3 Previous studies involving micro-generation and networks .......... 46 2.4.4 Areas of uncertainty....................................................................... 48 2.5 Chapter Summary ...................................................................................... 49 3 Initial data analysis ......................................................................... 51 3.1 Chapter Introduction .................................................................................. 51 3.2 Chapter methodologies .............................................................................. 52 3.2.1 Comparing different resolution data .............................................. 52 3.2.2 Correlation of generation to demand ............................................. 52 3.2.3 Calculation of economic and emissions savings ........................... 53 3.3 Summary of the Data ................................................................................. 54 3.3.1 Development of fuel cell micro-CHP profiles ............................... 59 3.4 The benefits of using minute-scale data .................................................... 61 3.5 Correlation and export ............................................................................... 63 3.6 Energy use and emissions savings ............................................................. 68 3.7 Economic savings ...................................................................................... 73 3.8 Comparison with previous micro-CHP research ....................................... 75 3.9 Chapter Summary ...................................................................................... 76 4 Methodology of network analysis .................................................. 79 4.1 Chapter Introduction .................................................................................. 79 10 4.2 The IPSA modelling environment ............................................................. 80 4.3 Development of an IPSA model ................................................................ 81 4.3.1 Representing micro-generation and heat pumps on the network ... 81 4.3.2 Parameters to be monitored ........................................................... 83 4.3.3 Model data ..................................................................................... 84 4.4 Developing a system to run load flow analysis.......................................... 84 4.4.1 Outputs generated by the Python scripts ....................................... 86 4.4.2 The scenarios that were tested ....................................................... 87 4.4.3 Determining voltage limits ............................................................ 89 4.4.4 Extracting specific results from the model output data ................. 89 4.5 Evaluating the network model ................................................................... 90 4.5.1 Evaluating whether micro-generation can affect neighbouring