Once again, thank you for the clarification.  I had forgotten that LMP was 
location specific (despite it being in the name).

From: [email protected] 
[mailto:[email protected]] On Behalf Of Ray Zimmerman
Sent: Tuesday, July 16, 2013 1:04 PM
To: MATPOWER discussion forum
Subject: Re: Smartmarket clearing price

Hi Trevor,

I think you are missing one important point. The output.co refers to "cleared 
offers", so output.co.P.prc contains, not the offer price, but the market 
clearing price. In the case of a uniform price auction, it will correspond to 
the lambda.

In response to your last question, *all* of the values of LAM_P correspond to 
the marginal unit. That is, each represents a location-specific (i.e. nodal) 
price. If there is no congestion or losses, the LAM_P will all be equal 
(uniform). You can think of LAM_P as "the cost at which a generator at this 
location would be marginal". With losses and congestion, you can have multiple 
marginal units at different prices depending on their location.

--
Ray Zimmerman
Senior Research Associate
B30 Warren Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645





On Jul 15, 2013, at 9:55 AM, "Hardy, Trevor" 
<[email protected]<mailto:[email protected]>> wrote:


The printed results from the smartmarket module produces an output that shows 
the revenue, costs, and net profit from the operation of the generators for 
that hour.  I have found that when I calculate the review using the formulas 
below, I get value that match the smartmarket results.

gen_revenue = sum(output.co.P.prc .* output.co.P.qty,2);

In thinking about this more, though, it seems this would only be the case if 
the generators were paid what they bid.  I'm running the market with uniform 
pricing set by the last marginal unit which I take to mean that all accepted 
generation is paid the same rate regardless of their offer price.

My questions:

1 - Is my understanding of uniform pricing in this context correct?
2 - If my understanding is correct, it seems like the smartmarket prices are 
not being correctly calculated in the printed summary; is this true?  It seems 
the revenue for each generator should be something like:

gen_revenue = sum(marginal_lambda * output.co.P.qty,2);
where marginal_lambda is the price offered/bid by the marginal unit.

3 - If this new revenue equation is correct for markets with uniform pricing, 
how do I determine which of the values of LAM_P in the results are for the 
marginal unit?  Is it the highest value?


Trevor


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