Subject: Re: Consumption for for GE1.5
From: [email-masked]
To: [email-masked]
Cc: [email-masked], [email-masked], [email-masked]
Date: Wed, 15 May 2002 01:15:00 -0700 (PDT)

Kevin,

We routinely prepare that data and it is available for all our turbines.  The 
problem is that the consumption/production is a net number for a 5.5 minute 
period so we do not know what the turbine loads are, only what they are 
netting.

This leaves two questions:

1. What is the turbine consuming during normal operation (including standby, 
full power, etc) and
2. What is the potential financial liability a particular site has for 
consumed power.

The first question we cannot answer with the SCADA data because the SCADA 
data is a net number.  This one will require actual measurement of data to 
ascertain.

The second question we cannot answer with the SCADA data unless the frequency 
of the measurement coincides with the 5.5 minute SCADA periodicity.

Regarding the second question:

Since we will be charged a different rate for consumed power (a "retail" 
rate) versus the rate we are paid for produced power (the "wholesale" rate) 
we cannot depend on a net metering solution with an arbitrary frequency.  
Taking a look at extremes by way of example:  If we are netting on a monthly 
basis then we will never owe anything under a net metering solution.  This is 
because in normal operation the turbine always produces more power than it 
consumes on a monthly basis.  On the other hand if the frequency is based on 
a 1 minute periodicity then we will have 2 instances of individual minutes.  
One would be a minute in which we produced power and sold it at the retail 
rate and the other would be a minute where we consumed power and purchased it 
at the retail rate.  This is because the turbine is not producing power 
during every minute of the month.   There are an infinite number of 
permutations because you can set the time interval to an infinite number of 
values.

Our current value is a net number, based on a 5.5 minute interval.  If the 
utility is basing their measurement on a different frequency then we will 
certainly get a different total for power consumed,

The other issue is the location of the measurement.  If the measurement is at 
the substation then the net number is an aggregate of the wind turbines which 
dampens the impact of a particular turbine (good for us).  If the measurement 
is with our SCADA system at the individual turbine then we maximize the 
impact if a particular turbine is down for any reason while the remaining 
turbines are operating (bad for us).

Therefore to more fully understand the 2nd question from Mark we also need to 
know 2 additional points:

1.  What is the proposed frequency for the metering?
2.  Where is the measurement going to take place?

As mentioned earlier, we can provide the net production/consumption for each 
5.5 minute interval.  However, I think the only way we can fully address this 
question is to run a test program based on the answers to these two last 
questions.

Regards,
Hollis

Kevin Cousineau
05/15/2002 07:25 AM
To: Mark Ratekin/EWC/Enron@ENRON
cc: Mark Fisher/EWC/Enron@Enron, Mark Eilers/EWC/Enron@ENRON, Hollis 
Kimbrough/EWC/Enron@ENRON 

Subject: Re: Consumption for for GE1.5  

Mark, Mark and Mark: 

I have reviewed the attached power curve and clearly it will not help in 
formulating an answer to your question. 

I would like to ask Mark Fisher to look at a typical installation (any one of 
our field sites) and give us data on kWh consumed by several turbines over a 
multi-month period with data arranged month by month. Perhaps one or two 
turbines at Monfort would be the best because we can look at a whole year of 
data. This would tell us what was produced and what was consumed in energy. 

Mark Eilers, what do you think? 

Regards 

KLC 

Mark Ratekin
05/14/2002 04:24 PM
To: Kevin Cousineau/EWC/Enron@ENRON
cc: Mark Fisher/EWC/Enron@Enron, Mark Eilers/EWC/Enron@ENRON, Hollis 
Kimbrough/EWC/Enron@ENRON 

Subject: Re: Consumption for for GE1.5  

Attached is the final power curve results from the Tehachapi 1.5 Prototype, 
which includes the power consumption.  The page was scanned from the NREL 
Test Report.  If you have any questions or need the entire document feel free 
to contact me.

Best Regards,

Mark