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Wind Generation in New Zealand. Kieran Devine, Doug Goodwin System Operations Transpower New Zealand Limited. Overview. New Zealand and the Power System New Zealand’s Energy Strategy The Electricity Market Wind Generation in New Zealand Wind Integration Investigations. - PowerPoint PPT Presentation
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Wind Generation in New Zealand
Kieran Devine, Doug Goodwin
System Operations
Transpower New Zealand Limited
Overview
• New Zealand and the Power System
• New Zealand’s Energy Strategy
• The Electricity Market
• Wind Generation in New Zealand
• Wind Integration Investigations
New Zealand’s Place in the World
No opportunity for interconnection
Have to meet all our own electricity needs
New Zealand power system• Two AC island power systems
connected by an HVDC link
• Peak/Minimum demand– North Island 4500/1680 MW (37%)
– South Island 2250/1300 MW (58%)
• Installed capacity (generation)– North Island 5300 MW
– South Island 3400 MW
• Total Energy, 42,000 GWhr
NZ Energy Strategy (2008)
• Generation will be 90% renewable by 2025
• Currently 65% renewable: 54% hydro, 8% geothermal, 3% wind
• Wind is expected to be the main contributor to achieving the 90% target
• No new baseload thermal (coal or gas) generating plantallowed for 10 years
• Emissions trading regime has been introduced
New Zealand Electricity Market
• Security constrained economic dispatch– Gross pool, energy market, no capacity payments– Compulsory market, but no compulsion to offer– Locational nodal prices, no price caps– Energy and reserves co-optimised– No rights to transmission capacity
Te Apiti (91 MW)Tararua (161 MW)Te Rere Hau (48 MW)
White Hill (57 MW)West Wind (143 MW)from 2009
Wind resource
Existing 357MWImminent 143MWProposed 2014MW
Hawkes Bay Wind Farm (225 MW)Titiokura (48 MW)Te Waka (102 MW)
Mill Creek (71 MW)
Mount Cass (69 MW)
Project Hayes (630 MW)Kaiwera Downs (240 MW)Mahinerangi (200 MW)
Motorimu (110 MW)
Waverley (135 MW)
Te Uku (84 MW)Taharoa (100 MW)
Transmission and Demand
0
500
1,000
1,500
2,000
2,500
3,000
3,500
1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s since2000
leng
th o
f tr
ansm
issi
on li
nes
built
(km
)
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
length built Generated
elec
tric
ity g
ener
atio
n (G
Wh)
mid
-dec
ade
Wind in the Market
• Electricity market and ancillary service market rules are based around
non-intermittent generation• Wind Offers into the market for next day• Currently there is no national wind forecast• Persistence Offer within 2 hour gate closure:
– Offer for next 5 minutes is current output• Wind is occasionally constrained off for
system security reasons.
Te Apiti Constraint - 4 August 2007
-400
-300
-200
-100
0
100
200
20:24:00 21:36:00 22:48:00 00:00:00
Time
Ou
tpu
t o
r tr
ansf
er (
MW
)
Te Apiti HVDC Te Apiti potential
Constrained wind generation
Total NZ Wind Generation (MW)
0
50
100
150
200
250
300
19-Jul-2007 00:00 21-Jul-2007 00:00 23-Jul-2007 00:00 25-Jul-2007 00:00 27-Jul-2007 00:00 29-Jul-2007 00:00 31-Jul-2007 00:00
Date
Ou
tpu
t (M
W)
As variable as ever
Daily NZ wind generation production
0
1000
2000
3000
4000
5000
6000
7000
1/07/2007 31/07/2007 30/08/2007 29/09/2007 29/10/2007 28/11/2007 28/12/2007 27/01/2008 26/02/2008 27/03/2008 26/04/2008 26/05/2008 25/06/2008
Day
Pro
du
cti
on
(M
Wh
)
MWh 30 per. Mov. Avg. (MWh)
Low output in first half of 2008
Hydro Inflows 38% 0f average
28 December 2007
0
10
20
30
40
50
60
70
80
90
100
00:00:00 04:48:00 09:36:00 14:24:00 19:12:00 00:00:00
Time
Ou
tpu
t (M
W)
Te Apiti Tararua III
`
Correlation of wind generation
Correlation over 3 years,
r2=0.68
31 January 2008
0
50
100
150
200
250
00:00:00 06:00:00 12:00:00 18:00:00 00:00:00
Time
Win
d g
en
era
tio
n o
utp
ut
(MW
)
Manawatu wind generation White Hill
`
Correlation of wind generation
Correlation over 12 months, r2=0.17
Wind Generation Investigation Project (WGIP)
• Four phases
Wind Generation
Development Scenarios
ImplicationsPossible Options
Preferred options
What may happen with wind generation development in NZ
What will the effects be?
What can we do?
What are the preferred options
WGIP Recommendations
• Wind generation capability:– Review ancillary services cost allocations– Review ride through capability requirements– Need for tested wind farm models
• Pre-dispatch processes– Incorporation of wind generation forecasts– Ability to meet large sudden unpredicted changes
• Continue to monitor, currently only 3 years data
Amount of wind generation
1000 MW100 MW 10000 MW
Effect
Noticeable
Critical
Lack of frequency support:- Increased reserves costs
Lack of voltage support:- Increased costs- More transmission reactive devices
Variability:- Increased frequency regulation costs
Unpredictability:- Market outcomes- Security
Conclusions (Part 1)
• Most of the potential issues are moderate in impact or will occur 5-10+ years in the future
• No immediate need to limit the connection of wind generation
• No defined technical upper limit to wind generation
• The lack of operational experience and the initial geographic concentration of wind generation in NZ places limitations on the analysis carried out
Conclusions (Part 2)
• Main issues for immediate further attention arise from effect of variability on pre-dispatch processes
• Technical capability of wind generation much improved over last few years
• Some areas for standards and code changes:– Ride through capability– Effect of variability and capability on ancillary services
requirements
• Other issues are less urgent and may be dealt with by normal regulator processes used to develop codes.