Merchant Plant - Generating Revenue

Hi everyone,

I am new to SAM and trying to execute a solar PV "Merchant Plant," but I am uncertain how to generate revenues from electricity sales. I am trying to sell total production through the "Energy Market Revenue" option and none through the Ancillary Service Market Revenue option. 

Can someone explain how I would do that? Currently, no matter how I manipulate the Cleared Capacity and $/Mwh, I get the same error:  The generation is not sufficient to meet the ancillary markets requirements.  Specifically, sum of cleared capacity [X] MW exceeds system capacity 0 MW at timestep 0.

I appreciate all your input and advice!

Hi Hamilton,

There is a bug in the Merchant Plant model that we are working to fix for the next update to SAM 2020.2.29, which we hope to release by the end of this month (July 2020).

github.com/NREL/SAM/issues/346

Best regards,
Paul.

Thank you very much for your quick reply! How much different is the PPA option? Could I have the PPA price set at retail electricity rates to create comparable revenue results to a plant under the "Merchant" option? 

Hi Hamilton,

The PPA financial models calculate revenue based on a fixed PPA price with optional time-of-delivery (TOD) multipliers. The Merchant plant calculates revenue based on a time series of power prices with options to model revenue from both energy and ancillary service market revenue, and for capacity payments.

You could use the TOD multipliers to approximate the varying power price of a Merchant Plant for energy market revenue.

For PPA projects with battery storage, you also provide retail electricity rates to account for the cost of electricity that charges the battery, but this is considered a cost, not a source of revenue.

Best regards,
Paul.

Hi,

I'm having a similar problem, using the Generic Battery, Merchant option. I get various versions of the message below, depending on the values I put in the Cleared Capacity column of the Lifetime Data matrix in the Energy Market Revenue section. I haven't selected any ancillary service revenue options, and using manual dispatch, with five selected charging hours followed by four selected discharge hours each day. The system is oversized, so that shouldn't be the problem. Can you help me understand how the Cleared Capacity column works? Please let me know if you would like more info.

thanks, Bob

Hi Bob,

There is an extensive discussion on the topic of using the Battery  model with the Merchant Plant here: sam.nrel.gov/forum/forum-general/3108-bi-directional-inverter-for-battery-systems.html?start=6#8598 .

Please follow up on that thread if you have any additional questions or comments.

Best regards,
Paul.