Operating Reserves and Variable Generation

TLDR: In this article, the requirements of the power system as it relates to the needs of operating reserves are generalized and a survey of operating reserve management is presented. But the focus is on variable generation.

Abstract: This report tries to first generalize the requirements of the power system as it relates to the needs of operating reserves. It also includes a survey of operating reserves and how they are managed internationally in system operations today and then how new studies and research are proposing they may be managed in the future with higher penetrations of variable generation.

Figures

Figure 21: New frequency dependent BAAL requirement.

Table IX: Comparison of different stochastic methods

Figure 34: Summary of changes in hourly maximum regulation deployments of 15,000-MW wind capacity.

Figure 20: ISO and RTO regions in North America. (www.isorto.org)

Figure 6: Wind power step-change magnitude and standard deviation for different wind turbine sets.

Figure 17: Governor droop curve with dead band.

Full text

Operating Reserves and
Variable Generation
A comprehensive review of current strategies,
studies, and fundamental research on the impact
that increased penetration of variable renewable
generation has on power system operating
reserves.
Erik Ela, Michael Milligan, and Brendan Kirby
NREL is a national laboratory of the U.S. Department of Energy, Office of Energy
Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
Technical Report
NREL/TP-5500-51978
August 2011
Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory
1617 Cole Boulevard
Golden, Colorado 80401
303-275-3000 • www.nrel.gov
Operating Reserves and
Variable Generation
A comprehensive review of current strategies,
studies, and fundamental research on the impact
that increased penetration of variable renewable
generation has on power system operating
reserves.
Erik Ela, Michael Milligan, and Brendan Kirby
Prepared under Task No. WE110920
Cover photo is NREL PIX 19498.
NREL is a national laboratory of the U.S. Department of Energy, Office of Energy
Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
Technical Report
NREL/TP-5500-51978
August 2011
Contract No. DE-AC36-08GO28308

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Table of Contents
List of Figures............................................................................................................................................... v
List of Tables ............................................................................................................................................... vi
Abstract ....................................................................................................................................................... vii
Abbreviations and Definitions ...................................................................................................................viii
Acknowledgements....................................................................................................................................... x
1 Introduction........................................................................................................................................... 1
2 Power System and Operating Reserves Overview................................................................................ 4
2.1 Regulating Reserves.................................................................................................................... 12
2.2 Following Reserves..................................................................................................................... 18
2.3 Contingency Reserves................................................................................................................. 20
2.4 Ramping Reserves ...................................................................................................................... 22
2.5 Primary Reserves (Under Contingency Reserves)...................................................................... 24
2.6 Secondary Reserves (Under Contingency Reserves and Ramping Reserves) ............................ 28
2.7 Tertiary Reserves (Under Contingency Reserves and Ramping Reserves) ................................ 28
3 Operating Reserves in Practice ........................................................................................................... 29
3.1 North America (NERC) .............................................................................................................. 29
3.1.1 Regulating Reserves............................................................................................................ 32
3.1.2 Following Reserves............................................................................................................. 36
3.1.3 Contingency Reserves......................................................................................................... 36
3.1.4 Ramping Reserves............................................................................................................... 38
3.1.5
Primary Reserves ................................................................................................................ 38
3.1.6 Secondary Reserves ............................................................................................................ 38
3.1.7 Tertiary Reserves ................................................................................................................ 39
3.2 Key North American Regional Differences................................................................................ 40
3.2.1 Regulating Reserves............................................................................................................ 40
3.2.2 Following Reserve .............................................................................................................. 45
3.2.3 Contingency Reserve .......................................................................................................... 45
3.2.4 Ramping Reserve ................................................................................................................ 46
3.2.5 Primary Reserve.................................................................................................................. 46
3.2.6 Secondary Reserves ............................................................................................................ 49
3.2.7 Tertiary Reserves ................................................................................................................ 49
3.3 Europe: ENTSO-E (UCTE) ........................................................................................................ 50
iii

3.3.1 Regulating Reserves............................................................................................................ 50
3.3.2 Following Reserves............................................................................................................. 52
3.3.3 Contingency Reserves......................................................................................................... 52
3.3.4 Ramping Reserves............................................................................................................... 54
3.3.5 Primary Reserves ................................................................................................................ 54
3.3.6 Secondary Reserves ............................................................................................................ 55
3.3.7 Tertiary Reserves ................................................................................................................ 56
3.4 Summary ..................................................................................................................................... 57
4 New Proposed Methodologies and Renewable Integration Studies.................................................... 60
4.1 Large-Scale Renewable Integration Studies ............................................................................... 60
4.2 Academic Research..................................................................................................................... 78
4.3 Summary ..................................................................................................................................... 85
5 Conclusions and Discussion................................................................................................................ 87
6 References........................................................................................................................................... 89
iv

Frequently asked questions

Q1. What contributions have the authors mentioned in the paper "Operating reserves and variable generation: a comprehensive review of current strategies, studies, and fundamental research on the impact that increased penetration of variable renewable generation has on power system operating reserves" ?

In this paper, the authors define the term active power reserve as capacity used to maintain the active power ( also referred to as real power ) balance of the system. 

Q2. What are the future works mentioned in the paper "Operating reserves and variable generation: a comprehensive review of current strategies, studies, and fundamental research on the impact that increased penetration of variable renewable generation has on power system operating reserves" ?

Studies have been performed for existing systems to estimate the needs of the future for these systems if they were to have large penetrations of VG. For example, some studies may have been required to keep the current operating or market structure as constant for the future study. Others may have not had the data available for them to study the same types of impacts or same categories of Operating Reserve. Further work will likely use a tradeoff of these two advantages.