Simple winddiesel concept with high wind penetration in Cape Verde

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Simple wind-diesel conceptwith high wind
penetrationin Cape Verde

• Per Nørgård, Risø DTU, Denmark, pern_at_risoe.dtu.dk
• João Fonseca, Electra, Cabo Verde,
  j.fonseca_at_electra.cv

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Cabo Verde

• Independent (from Portugal) in 1955
• Population 500 000 at 10 islands
• Islands in study
• Santiago
• São Vicente
• Sal
• (Boa Vista)

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Cabo Verde

• Risø DTU as Technical Consultant
• for InfraCo (international project developer)
• in collaboration with Electra (local power
  utility company)

• Power generation based on diesel generation
• Excellent wind conditions
• High average wind speeds most of the year
• Very constant wind
• Low extreme wind speed

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Growing demand
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IPSYSan energy system simulation tool

• Characteristics
• Semi-static time series simulation (minutes time
  steps)
• Includes storage and memory functionalities
• Designed for mixed energy systems
• Performs energy balances and load flow analysis
  (power systems)
• Handles advanced and distributed control
• Developed by Risø DTU

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Simplified single line diagrams
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Operation strategy

• Minimum continuous diesel load
• Minimum instantaneous diesel load
• Minimum spinning reserve diesel capacity
• Minimum diesel capacity
• Minimum number of diesel generator units
• Minimum diesel operation time

• Minimum continuous load of the diesel engines
  30 (optional 50).
• To prevent the diesel engines from sooting up at
  low load.
• The wind power generation may be limited to
  fulfil this condition.

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Operation strategy

• Minimum continuous diesel load
• Minimum instantaneous diesel load
• Minimum spinning reserve diesel capacity
• Minimum diesel capacity
• Minimum number of diesel generator units
• Minimum diesel operation time

• Minimum instantaneous load of the diesel engines
  10.
• To prevent for negative load of the diesel
  generators.

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Operation strategy

• Minimum continuous diesel load
• Minimum instantaneous diesel load
• Minimum spinning reserve diesel capacity
• Minimum diesel capacity
• Minimum number of diesel generator units
• Minimum diesel operation time

• Minimum spinning reserve diesel capacity
  connected to the grid
• 200 of the observed fluctuation of the diesel
  load within the last hour and
• minimum 50 of the actual diesel load (if
  possible).
• To be prepared for the fluctuations in the wind
  power and in the load.

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Operation strategy

• Minimum continuous diesel load
• Minimum instantaneous diesel load
• Minimum spinning reserve diesel capacity
• Minimum diesel capacity
• Minimum number of diesel generator units
• Minimum diesel operation time

• Minimum diesel capacity connected to the grid
• 2 times the wind capacity connected to the grid.
• To ensure dynamic stability of the system.
• _at_ low load high wind
• wind turbines are shut down
• -gt diesel generators shut down

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Operation strategy

• Minimum continuous diesel load
• Minimum instantaneous diesel load
• Minimum spinning reserve diesel capacity
• Minimum diesel capacity
• Minimum number of diesel generator units
• Minimum diesel operation time

• Minimum number of diesel generator units
  connected to the grid
• 2
• Not to rely on a single diesel generator unit.

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Operation strategy

• Minimum continuous diesel load
• Minimum instantaneous diesel load
• Minimum spinning reserve diesel capacity
• Minimum diesel capacity
• Minimum number of diesel generator units
• Minimum diesel operation time

• Minimum operation time of a diesel engine
• 4 hours.
• To limit the number of start / stop of the diesel
  engines.

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Load profiles(3x3 days)
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Seasonal variation of wind
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IPSYS results (Sao Vicente)
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Summary of results
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Not utilised wind energy
1 p.u. 20 wind energy penetration
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Avoided diesel fuel
1 p.u. 20 wind energy penetration
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Minimum diesel load (2012)
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PPA Power Purchase Agreement

• Minimum wind energy leveltake pay _at_ high
  tariff
• Motivates wind power operatorto maximise
  production

• Additional wind energy_at_ low tariff
• Motivates diesel operatorto optimise operation

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Conclusions

• The most critical operation parameter is the
  minimum diesel load.
• Even at 40 wind energy penetration, the not
  utilised wind energy is only 10.
• 20 overinvestment in wind power capacity is
  proposed
• 22 MW -gt 28 MW -gt 0..10 not utilised wind
  energy.
• This seems economically feasible at 5 reduced
  generation cost (/kWh), with the expected demand
  growth.

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Thanks!Seeing you atStand 2463 (Hall 2)
Hall 2

• Per Nørgård
• Risø DTU, Denmark
• pern_at_risoe.dtu.dk