7Table of contents
Foreword ............................................................................................. 3Acknowledgements .................................................................................... 5Executive summary ....................................................................................15Part 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 ● Introduction ...................................................................................... 25 What is in this book? ............................................................................ 272 ● Why is variability a challenge? ................................................................. 31 Fluctuating supply ............................................................................... 31 Uncertainty ...................................................................................... 32 When is the balancing challenge greatest? ................................................... 333 ● Greater flexibility is the right response ....................................................... 35 What is flexibility? ............................................................................... 354 ● Key distinguishing features of power systems ................................................ 375 ● The Flexibility Assessment Method ............................................................ 416 ● Identifying the flexible resource ...............................................................43 Dispatchable power plants ..................................................................... 43 Energy storage ...................................................................................45 Interconnection for trade with adjacent areas ............................................... 46 Demand side management and response ..................................................... 47 Comparing areas using the Flexibility Index ..................................................487 ● How much of the flexible resource is available? ............................................. 51 Dispatchable power plant availability .........................................................51 Energy storage availability ..................................................................... 52 Interconnection availability .................................................................... 53 Demand side availability ........................................................................ 54 Grid strength and intelligence ................................................................. 55 Potential market and operational constraints ................................................588 ● What are the needs for flexibility? ............................................................. 69 Existing flexibility requirement ................................................................69 Additional requirements of VRE ................................................................ 719 ● Identifying the Present VRE Penetration Potential ........................................... 7710 ● What is the cost of balancing variable renewable energy? .................................. 81 Key drivers of balancing costs ..................................................................82 Methodology for estimating balancing costs ..................................................84 Estimates of balancing costs . (84)
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811 ●Conclusions, recommendations to policy makers and next steps (87)
Conclusions (87)
Recommendations to policy makers (88)
Next steps and further research (90)
Part 2 (93)
12 ●Case study methodology (95)
The balancing timeframe (95)
Flexibility requirement of VRE (96)
T reatment of flexible resources (99)
Flexibility Index and Present VRE Penetration Potential (102)
Scoring and weighting of area attributes (104)
Case study results (105)
13 ●Great Britain and Ireland area (British Isles) (107)
Flexibility requirement of VRE (107)
Flexible
resources (109)
Flexibility Index and Present VRE Penetration Potential (111)
Area
constraints (113)
14 ●Spain and Portugal area (Iberian Peninsula) (119)
Flexibility requirement of VRE (119)
Flexible
resources (120)
Flexibility Index and Present VRE Penetration Potential (123)
Area
constraints (125)
15 ● Mexico (129)
Flexibility requirement of VRE (129)
Flexible
resources (130)
Flexibility Index and Present VRE Penetration Potential (133)
Area
constraints (134)
16 ● Nordic (137)
Flexibility requirement of VRE (137)
Flexible
resources (138)
Flexibility Index and Present VRE Penetration Potential (141)
Area
constraints (143)
17 ● Denmark (147)
Flexibility requirement of VRE (147)
Flexible
resources (149)
Flexibility Index and Present VRE Penetration Potential (151)
Area
constraints (152)
18 ● Japan (157)
Flexibility requirement of VRE (157)
Flexible
resources (159)
Flexibility Index and Present VRE Penetration Potential (161)
Area
constraints (162)
19 ●US West 2017 (167)
Flexibility requirement of VRE (167)
Flexible
resources (169)
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9 Flexibility Index and Present VRE Penetration Potential .................................... 171 Area constraints ................................................................................. 17320 ● Canada Maritime: the NBSO area ...............................................................
177 Flexibility requirement of VRE ................................................................. 177 Flexible resources ............................................................................... 178 Flexibility Index and Present VRE Penetration Potential .................................... 181 Area constraints ................................................................................. 182Annexes
A ● Other integration costs (189)
B ● Additional information on VRE technologies (203)
C ● Assumptions relating to dispatchable power plants in case-study areas (207)
D ● Defining the power area for analysis with the FAST tool .................................... 211
E ● The role of CCS in flexible power generation ................................................. 213
F ● The role of CHP in flexible power generation ................................................. 215
G ● Treatment of fundamental area attributes in the case-studies ............................. 217
H ● Acronyms ......................................................................................... 221
I ● References ....................................................................................... 225List of figures
ES.1. The FAST Method ................................................................................. 17ES.2. VRE deployment potentials today , from the balancing perspective (18)
1. Variable renewable energy shares in ETP BLUE Scenarios (2050) (27)
2. System integration challenges (28)
3. Variability in demand (upper line), and in net load (lower line) in a challenging week (31)
4. Overview of flexibility needs and resources (36)
5. Key distinguishing attributes of power areas assessed ............................................. 386. The FAST Method in a nutshell . (41)
7. T echnical ramping capabilities of power plants in the Nordic power area (44)
8. Flexible resource in dispatchable power plants (45)
9. Flexible resource in storage facilities (46)
10. Flexible resource in interconnections (46)
11. Flexible resource on the demand side (48)
12. Flexibility Index calculated for eight case study areas (49)
13. A fairly generic load curve example (51)
14. Availability of dispatchable power plants to provide flexibility (52)
15. Availability of storage facilities (53)
16. Availability of interconnection capacity (54)
17. Availability of the demand side (55)
18. Constraints on availability represented by the grid (56)
19. Power system interaction through an intelligent grid (57)
20. Operational and market constraints on availability (58)
21. Balancing areas in the eastern United States in 2007 (left), and assumed in 2024 (right) (59)
22. Effect of incentive on available flexible resources in the market place (61)
23. Effect of 35% variable renewables in the West Connect area of the United States (62)
24. Managing uncertainty in the net load (66)
25. Existing and additional needs for flexibility (69)
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1026. Hourly up-ramping in load (top) and net load (bottom) in the western United States (MW) (70)
27. Assessing the flexibility requirement of the VRE portfolio (71)
28. Impact of geographical spread, smoothing PV variability (73)
29. Impact of complementary VRE output on variability in California, July 2003 (73)
30. Solar and wind resource on a typical December day in the state of Victoria, Australia (74)
31. VRE potentials today, from the balancing perspective (78)
32. Global sample of VRE integration studies (81)
33. Balancing cost savings through operational and market measures (83)
34. Estimates of wind energy balancing costs (85)
35. Calculating net technical flexible resource (NTR) (102)
36. Attributes relating to VRE flexibility requirement (British Isles) (108)
37. Dispatchable plant portfolio (British Isles) (109)
38. T echnical flexibility of dispatchable plant (British Isles) (109)
39. L ikely operation of dispatchable plant (British Isles) at minimum demand (top figure), and peak
(bottom figure) (110)
40. Attributes relating to storage availability (British Isles) (113)
41. Attributes relating to demand-side resource availability (British Isles) (114)
42. Attributes relating to interconnection availability (British Isles) (115)
43. Availability of total flexible resource (British Isles) (116)
44. Attributes relating to VRE flexibility requirement (Iberian Peninsula) (120)
45. Dispatchable plant portfolio (Iberian Peninsula) (121)
46. T echnical flexibility of dispatchable plant (Iberian Peninsula) (121)
47. L ikely operation of dispatchable plant (Iberian Peninsula) at minimum demand (top figure), and
peak (bottom figure). (122)
48. Attributes relating to storage availability (Iberian Peninsula) (125)
49. Attributes relating to demand-side resource availability (Iberian Peninsula) (126)
50. Attributes relating to interconnection availability (Iberian Peninsula) (127)
51. Availability of total flexible resource (Iberian Peninsula) (127)
52. Attributes relating to VRE flexibility requirement (Mexico) (130)
53. Dispatchable plant portfolio (Mexico) (131)
54. T echnical flexibility of dispatchable plant (Mexico) (131)
55. L ikely operation of dispatchable plant (Mexico) at minimum demand (top figure), and peak
(bottom figure) (132)
56. Attributes relating to interconnection availability (Mexico) (135)
57. Availability of total flexible resource (Mexico) (136)
58. Attributes relating to VRE flexibility requirement (Nordic) (138)
59. Dispatchable plant portfolio (Nordic) (139)
60. T echnical flexibility of dispatchable plant (Nordic) (139)
61. L ikely operation of dispatchable plant (Nordic) at minimum demand (top figure), and peak
(bottom figure) (140)
62. Attributes relating to demand-side resource availability (Nordic) (143)
63. Attributes relating to interconnection availability (Nordic) (144)
64. Availability of total flexible resource (Nordic) (145)
65. Attributes relating to VRE flexibility requirement (Denmark) (148)
66. Dispatchable plant portfolio (Denmark) (149)
67. T echnical flexibility of dispatchable plant (Denmark) (149)
68. L ikely operation of dispatchable plant (Denmark) at minimum demand (top figure), and peak
(bottom figure) (150)
69. Attributes relating to demand-side resource availability (Denmark) (153)
70. Attributes relating to interconnection availability (Denmark) (153)
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1171. Availability of total flexible resource (Denmark) (154)
72. Attributes relating to VRE flexibility requirement (Japan) (158)
73. Dispatchable plant portfolio (Japan) (159)
74. T echnical flexibility of dispatchable plant (Japan) (159)
75. L ikely operation of dispatchable plant (Japan) at minimum demand (top figure), and peak
(bottom figure) (160)
76. Attributes relating to storage availability (Japan) (163)
77. Attributes relating to demand-side resource availability (Japan) (164)
78. Availability of total flexible resource (Japan). (164)
79. Attributes relating to VRE flexibility requirement (US West 2017) (168)
80. Dispatchable plant portfolio (US West 2017) (169)
81. T echnical flexibility of dispatchable plant (US West 2017) (169)
82. L ikely operation of dispatchable plant (US West 2017) at minimum demand (top figure), and
peak (bottom figure) (170)
83. Attributes relating to storage availability (US West 2017) (173)
84. Attributes relating to demand-side resource availability (US West 2017) (174)
85. Attributes relating to interconnection availability (US West 2017) (175)
86. Availability of total flexible resource (US West 2017) (175)
87. Attributes relating to VRE flexibility requirement (NBSO) (178)
88. Dispatchable plant portfolio (NBSO) (179)
89. T echnical flexibility of dispatchable plant (NBSO) (179)
90. L ikely operation of dispatchable plant types (NBSO) at minimum demand (top figure), and
peak demand (bottom figure) (180)
91. Attributes relating to demand-side resource availability (NBSO) (183)
92. Attributes relating to interconnection availability (NBSO) (184)
93. Availability of total flexible resource (NBSO) ..................................................... 184A1. An example of a scenario approach to integration cost analysis ................................ 190A2. Capacity credit for wind in selected regions ..................................................... 191A3. Capacity credit for solar technologies in the Western United States ............................ 192A4. Adequacy costs of wind by region (energy normalised approach) ............................... 193A5. Breakeven distances by capacity factor and electricity value ................................... 196A6. Scale economies in transmission assuming fixed capacity and distance ........................ 197A7. Transmission costs of wind and system optimisation in the Eastern US ......................... 198A8. Economies of scale (voltage) in EWITS 2010 ...................................................... 198A9. Transmission costs of wind in Europe ............................................................. 199A10. T otal transmission investment in Europe (EWIS) ................................................ 199A11. Transmission costs in Europe (GreenNet) ........................................................ 199A12. Cost of wind transmission in Ireland ............................................................. 200B1. Variability of wind power over different time scales (Ireland, 2005) ............................ 203B2. Maximum up-ramps of wind (MW/hour) in Finland, 2005-2007 .................................. 204B3. Variability of solar PV output over eight sites in California ...................................... 205B4. Wind and wave variability correlation ............................................................ 206D1. Power areas and power systems . (211)
List of tables
1. Average penetrations of wind energy in leading areas, 2009 (26)
2. Flexible resources in the Iberian Peninsula (49)
3. Mean errors in wind power forecasts (% of installed wind capacity) (65)
4. Scope of integration cost studies (82)
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125. T echnical flexible resource from dispatchable power plants in the British Isles (101)
6. FIX values for up-ramping (103)
7. FIX values for down-ramping (103)
8. VRE portfolio assumptions (British Isles) (107)
9. VRE flexibility requirement (British Isles) (107)
10. T echnical flexible resource from dispatchable power plants (British Isles) (111)
11. T echnical flexible resources (British Isles) (112)
12. Existing flexibility requirement and Flexibility Index (British Isles) (112)
13. Present VRE Penetration Potential (British Isles) (112)
14. VRE portfolio assumptions (Iberian Peninsula) (119)
15. VRE flexibility requirement (Iberian Peninsula) (119)
16. T echnical flexible resource from dispatchable power plants (Iberian Peninsula) (123)
17. T echnical flexible resources (Iberian Peninsula) (123)
18. Existing flexibility requirement and Flexibility Index (Iberian Peninsula) (124)
19. Present VRE Penetration Potential (Iberian Peninsula) (124)
20. VRE portfolio assumptions (Mexico) (129)
21. VRE flexibility requirement (Mexico) (129)
22. T echnical flexible resource from dispatchable power plants (Mexico) (133)
23. T echnical flexible resources (Mexico) (133)
24. Existing flexibility requirement and Flexibility Index (Mexico) (134)
25. Present VRE Penetration Potential (Mexico) (134)
26. VRE portfolio assumptions (Nordic) (137)
27. VRE flexibility requirement (Nordic) (137)
28. T echnical flexible resource from dispatchable power plants (Nordic) (141)
29. T echnical flexible resources (Nordic) (141)
30. Existing flexibility requirement and Flexibility Index (Nordic)v (142)
31. Present VRE Penetration Potential (Nordic) (142)
32. VRE portfolio assumptions (Denmark) (147)
33. VRE flexibility requirement (Denmark) (147)
34. T echnical flexible resource from dispatchable power plants (Denmark) (150)
35. T echnical flexible resources (Denmark) (151)
36. Existing flexibility requirement and Flexibility Index (Denmark) (151)
37. Present VRE Penetration Potential (Denmark) (152)
38. VRE portfolio assumptions (Japan) (157)
39. VRE flexibility requirement (Japan) (158)
40. T echnical flexible resource from dispatchable power plants (Japan) (161)
41. T echnical flexible resources (Japan) (161)
42. Existing flexibility requirement and Flexibility Index (Japan) (162)
43. Present VRE Penetration Potential (Japan) (162)
44. VRE portfolio assumptions (US West 2017) (167)
45. VRE flexibility requirement (US West 2017) (168)
46. T echnical flexible resource from dispatchable power plants (US West 2017) (171)
47. T echnical flexible resources (US West 2017) (171)
48. Existing flexibility requirement and Flexibility Index (US West 2017) (172)
49. Present VRE Penetration Potential (US West 2017) (172)
50. VRE portfolio assumptions (NBSO) (177)
51. VRE flexibility requirement (NBSO) (177)
52. T echnical flexible resource from dispatchable power plants (NBSO) (181)
53. T echnical flexible resources (NBSO) (181)
54. Existing flexibility requirement and Flexibility Index (NBSO) (182)
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55. Present VRE Penetration Potential (NBSO) (182)
A1. Key drivers of adequacy costs (193)
A2. Issues requiring regulation (200)
A3. Stakeholders in transmission projects (201)
G1. Summary of fundamental attributes (220)
List of boxes
1. Distributed variable renewables (28)
2. Other integration challenges (29)
3. Curtailing variable output (35)
4. How flexible is nuclear power? (43)
5. Dynamic line rating (57)
6. Balancing areas (59)
7. Power exchanges (60)
8. Spanish PV experiences (65)
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