Impact of Microgeneration Systems on the Low-Voltage Electricity Grid Energy in Buildings and Communities Programme October 2014 A Report of Annex 54 “Integration of Micro- Generation and Related Energy Technologies in Buildings” Edited by M. Sasso (Università degli Studi del Sannio, Italy) – Subtask B Leader Evgueniy Entchev (National Resources Canada, Canada) – Operating Agent Peter Tzscheutschler (Technische Universität München, Germany) – Operating Agent On behalf of IEA EBC Annex 54 © Copyright: Copying with reference to “IEA EBC Annex 54 Integration of Micro-Generation and Related Energy Technologies in Buildings” permitted. Technische Universität München, Germany 2014 All property rights, including copyright, are vested in Technische Universität München, Operating Agent for EBC Annex 54, on behalf of the Contracting Parties of the International Energy Agency Implementing Agreement for a Programme of Research and Development on Energy in Buildings and Communities. Published by Technische Universität München, Germany, 2014 Disclaimer Notice: This publication has been compiled with reasonable skill and care. However, neither Technische Universität München nor the EBC Contracting Parties (of the International Energy Agency Implementing Agreement for a Programme of Research and Development on Energy in Buildings and Communities) make any representation as to the adequacy or accuracy of the information contained herein, or as to its suitability for any particular application, and accept no responsibility or liability arising out of the use of this publication. The information contained herein does not supersede the requirements given in any national codes, regulations or standards, and should not be regarded as a substitute for the need to obtain specific professional advice for any particular application. Citation: Ken Darcovich, Evgueniy Entchev, et.al: “An International Survey of Electrical and Domestic Hot Water Load Profiles for Micro-cogeneration Performance Simulations”, published by Technische Universität München, Germany, 10/2014 Participating countries in EBC: Australia, Austria, Belgium, Canada, P.R. China, Czech Republic, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Japan, Republic of Korea, the Netherlands, New Zealand, Norway, Poland, Portugal, Spain, Sweden, Switzerland, Turkey, United Kingdom and the United States of America. This document may be downloaded from: www.iea-ebc.org 2 Impact of Microgeneration Systems on the Low-Voltage Electricity Grid Energy in Buildings and Communities Programme October 2014 A Report of Annex 54 “Integration of Micro- Generation and Related Energy Technologies in Buildings” Authored by: Nick Kelly (University of Strathclyde, UK) M. Sasso (Università degli Studi del Sannio, Italy) G. Angrisani (Università degli Studi del Sannio, Italy) C. Roselli (Università degli Studi del Sannio, Italy) 3 Acknowledgements This report is the result of an international project performed within Annex 54 of the IEA/EBC programme. We would like to express our great appreciation to the participants of Annex 54 for their contribution as well as for the support given by different national bodies. The guidance of the EBC Executive Committee is gratefully acknowledged. Ken Darcovich (Subtask A Leader), Evgueniy Entchev, Peter Tzscheutschler (Operating Agents) 4 Table of Contents Acknowledgements ......................................................................................... 4 Table of Contents ............................................................................................ 5 1 Overview ................................................................................................... 6 2 Microgeneration and the Grid ................................................................... 7 2.1 Characteristics of Contemporary Electricity Generation ........................................................................ 8 2.2 The Challenge Posed By Microgeneration .............................................................................................. 9 3 Impact of Microgeneration on Existing Networks .................................... 13 3.1 Power Flows .......................................................................................................................................... 13 3.2 Voltage Variation .................................................................................................................................. 14 3.3 Harmonics ............................................................................................................................................. 15 4 Accommodating Microgeneration in Current Networks ........................... 17 4.1 Mitigating Microgeneration Impacts in Networks ................................................................................ 17 5 Microgeneration and Future Networks .................................................... 19 5.1 Smart Grids and Virtual Power Plant .................................................................................................... 19 5.2 Control and Communication Mechanisms ............................................................................................ 22 5.3 The Role of Storage in Future Networks ............................................................................................... 23 5.4 Electric Vehicles .................................................................................................................................... 26 6 Conclusions ............................................................................................. 29 6.1 Microgeneration within the Context of Existing Networks ................................................................... 29 6.2 Microgeneration Impacts and Mitigation ............................................................................................. 30 6.3 Microgeneration and Future Networks ................................................................................................ 30 References .................................................................................................... 32 Background Information ............................................................................... 37 Annex 54 ........................................................................................................................................................... 40 5 1 Overview The primary function of Annex 54 is the analysis of microgeneration performance in buildings. Within the context of Annex 54, the term ‘microgeneration’ relates to a broad range of low-carbon technologies that can provide heating, cooling and/or power to buildings and communities. These include fuel cells and engine-based polygeneration systems, heat pumps, PV, micro wind power and biomass. Microgeneration technologies can be deployed individually or in combination (so-called hybrid systems). Whilst the primary use of microgeneration is to service the energy demands of a building or a community, microgeneration technologies could also play a role in wider energy networks such as communal heating schemes or (more typically) local electrical networks. However, the widespread participation of microgeneration in an energy network presupposes that those networks have evolved to accommodate and best utilise the microgeneration resources. Currently, this is rarely the case and microgeneration technologies tend to be connected piecemeal to existing networks, which have been designed to transport power, in one direction, from large central generators to the end user at the end of the network. The role of this report is to set the operation of microgeneration in buildings within this wider operational context. The report therefore focuses on connection into electrical networks and develops two main themes. First, the impact of microgeneration on existing electrical systems is explored. Second, the report looks ahead as to how microgeneration could be best utilised in energy networks – this will encompass approaches to control, related technologies such as energy storage (including hybrid vehicles) and demand-side control. The report draws on studies undertaken by Annex 54 partner organizations, papers presented at recent Microgen conferences [1,2] – organized by Annex members – and work done within the Highly Distributed Energy Futures (HIDEF, 2013) consortium, a group of University partners who were the UK representatives on the Annex. 6 2 Microgeneration and the Grid Building-integrated microgeneration is an emergent technology and as such does not yet make a significant contribution to the overall energy supply. However, the deployment of a range of microgeneration technologies is proceeding apace, though unevenly, throughout the developed world. For example, the most widely deployed microgeneration technology is currently PV; in the EU it is estimated that approximately 70 GW of photovoltaic capacity has been installed to date [3], of which almost half has been installed in Germany [4]. Micro-wind is also rapidly expanding where there is a viable resource. For example 22 MW of micro wind turbine capacity [5] is now installed in the UK as part as a rapid upsurge in microgeneration. In Japan, micro-CHP has gained a foothold in the domestic market with approximately 100,000 residential engine-based units installed and approximately 30,000 PEM fuel-cell-based units installed since 2009 [6]. However, the deployment of micro-CHP and polygeneration in other countries has been less spectacular.