The Value of Wind -> Electrical Energy  from the Breamlea Wind Generator
(update: February 1996)

Accurate data logging has now been in progress continuously for six months at the Breamlea wind generator. With the benefit of additional data from the Victorian Power Exchange, it is quite feasible to correlate the two data sets for each half-hour interval of the electricity trading pool. The results are set out in the table below:


Month 		July95	Aug95	Sep95	Oct95	Nov95	Dec95	TOTALS
Export kWh	7661	7156	8297	11159	10362	9937	54572
Vic. Demand MW	4845	4695	4613	4459	4384	4182	4530*
S M P  $/MW	$62.44	$38.17	$29.35	$40.67	$37.15	$50.25	$43.01*
Avoided cost #	$500	$260	$268	$460	$414	$480	$2382
(by Powercor)
                                                               (*averages)




Notes: 
*	Demand and pool prices have been moderately low, but are not unexpected, considering new market structure with competition from generators, while retail prices are yet to experience discounting for the majority of users.

*	# The avoided cost is not simply the product of kWh x SMP figures in the table, but rather the TRUE value calculated on a half-hourly basis.  In this case the difference is hardly significant, and for the 6-month period is only 2.5% greater than a simple multiplication of the monthly averages. The main point is to demonstrate that  Breamlea energy is worth AT LEAST the time-weighted SMP to the local distribution business, and is sometimes of greater value than the volume-weighted SMP.  The savings to Powercor (above) do not take into account TUOS/DUOS charges or transmission losses, which would increase the worth of the savings to 6 to 8% above the values in the table.

*	For larger wind installations/farms there would be the additional benefits for the "poles & wires" side of the business in delaying or cancelling the costly upgrading of the distribution feeder in which the wind power is embedded. This assumes that the feeder would never be required to export to the rest of the network higher power levels than it was importing prior to the installation of the wind farm. Times of peak demand with no wind would obviously constitute a problem that may be addressable by demand management.

*	I have confirmed with VPX that all their data published in Excel spreadsheet format (on the Internet) uses Eastern Australian Standard Time throughout the year, as does the DataTaker data logger at Breamlea. The logger, made by Data Electronics, gains about 10 seconds per month and is regularly recalibrated. It is assumed that the demand figures as published by VPX are an average of demand (expressed in megawatt units of power) during the PRECEDING half-hour, as this is the way data loggers usually record any parameter they are measuring over extended time intervals.

*	Feedback, comments and criticisms of this document would be appreciated. 

                Michael Gunter   Breamlea Operations Group
				Alternative Technology Assocation
  Phone:(03)9376 7515  Fax: (03)9419 1678  Email: mickgg@suburbia.net

Internet: http://suburbia.net/~ata/breamlea.htm
(or try http://www.suburbia.net/~ata/breamlea.htm  
   or   http://suburbia.apana.org.au/~ata/breamlea.htm)
