"Driving Investment in Renewable Energy in Victoria"
- Extract from submission by Origin Energy to the Victorian Government - 1 February 2006
(The full document can be downloaded from this Victorian Department of Infrastructure website.)Start quote:
5. Impact of wind generation on the wider energy market
While wind energy represents a steadily growing component of renewable generation in Australia, and therefore a valid part of the sector’s capacity to abate GHG, its cost impact outside on the broader energy market needs to be considered.
Unreliable capacity requires additional generation support
Additional wind capacity will require two forms of generation support because of the intermittent nature of the underlying energy source:
- variability outside 5 minute dispatch intervals - gas turbine generation, which can take between 15 and 30 minutes to reach maximum output, is either required to run to adjust for wind generation variability or to stand idle as back up support6; and
- variability inside 5 minute dispatch intervals - ancillary services generation is required, sometimes at significant extra cost, to cater for wind generation variability.
The costs of both forms of generation support are ultimately borne by energy consumers. Moreover, these costs are magnified as greater amounts of wind generation are connected to the system and more generation support is required.7 This is compounded by inter-connector constraints from time to time as more generation support is required from other regions in the NEM.
- If the NEM is short of generation capacity to cover this variability, NEMMCO must contract additional reserves from outside the market, adding to the cost for market participants.
- It is realised that in countries where a substantial proportion of their energy supply mix is wind generation (such as Denmark and Germany) the effects of intermittency can be minimised as the number and spread of wind-farms increases. Australia’s wind industry is not of a comparable diversity and magnitude, nor is the interconnectedness of the NEM as advanced as it is in Europe.
"The chart below plots total half hourly Victorian demand (on the 5 highest peak load days between September 2003 and January 2006) against the total wind production for Victorian wind generation per half hour. Significant generation support was required to account for variable wind generation output during peak periods on these 5 days."
Source: Origin Energy.