Wind Generation in New Zealand

1
Wind Generation in New Zealand

• Kieran Devine, Doug Goodwin
• System Operations
• Transpower New Zealand Limited

2
Overview

• New Zealand and the Power System
• New Zealands Energy Strategy
• The Electricity Market
• Wind Generation in New Zealand
• Wind Integration Investigations

3
New Zealands Place in the World
No opportunity for interconnection Have to meet
all our own electricity needs
4
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

5
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
  plant allowed for 10 years
• Emissions trading regime has been introduced

6
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

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Wind resource
Hawkes Bay Wind Farm (225 MW) Titiokura (48
MW) Te Waka (102 MW)
Te Uku (84 MW) Taharoa (100 MW)
Te Apiti (91 MW) Tararua (161 MW) Te Rere Hau (48
MW)
Waverley (135 MW)
Mill Creek (71 MW)
Motorimu (110 MW)
White Hill (57 MW)
West Wind (143 MW)from 2009
Project Hayes (630 MW) Kaiwera Downs (240
MW) Mahinerangi (200 MW)
Mount Cass (69 MW)
Existing 357MW Imminent 143MW Proposed
2014MW
8
Transmission and Demand
3,500
50,000
45,000
3,000
40,000
2,500
35,000
30,000
2,000
length of transmission lines built (km)
mid-decade
electricity generation (GWh)
25,000
1,500
20,000
15,000
1,000
10,000
500
5,000
0
0
1920s
1930s
1940s
1950s
1960s
1970s
1980s
1990s
since
2000
length built
Generated
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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.

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Constrained wind generation
11
As variable as ever
12
Low output in first half of 2008
Hydro Inflows 38 0f average
13
Correlation of wind generation
Correlation over 3 years, r20.68
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Correlation of wind generation
Correlation over 12 months, r20.17
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Wind Generation Investigation Project (WGIP)

• Four phases

Wind Generation Development Scenarios
Implications
Possible Options
Preferred options
What may happen with wind generation
development in NZ
What can we do?
What are the preferred options
What will the effects be?
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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

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Critical
Unpredictability - Market outcomes - Security
Effect
Variability - Increased frequency
regulation costs
Lack of voltage support - Increased costs - More
transmission reactive devices
Lack of frequency support - Increased reserves
costs
Noticeable
1000 MW
100 MW
10000 MW
Amount of wind generation
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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

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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.

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Thanks for your attention