FTM PV-BESS system and ancillary market (Merchant)

Hi,

I noticed while modelling different ancillary services with different capacity percentage that SAM is calculatin the gross/net produced energy just as if it was calculating it for the energy market, in other words, usingthe produced energy form the PV system in these ancillary services and not only the BESS available capacity contribution, and then making the revenue calculations accordingly, which is inacurrate.

Is there a way to seperate these revenues? or perthaps monitor the BESS production only, and making SAM base the results of financial metrics only on that? 

Thank you!

Best Regards,
Ali

Hi Ali,

As of SAM 2025.4.16, for the PV Battery / Merchant Plant configuration, it is not possible to separate power flow to the grid from the PV System and Battery for financial model calculations.

You can use the "Electricity to grid from battery AC (kW)" and "Electricity to grid from system AC (kW)" output variables to see these power flows, and possibly to export the data for revenue calculations outside of SAM. (To export the data from SAM, display the variables on the Data Tables tab and use the buttons above the table to export the data.)

Can you provide more details or perhaps a link to a description of the arrangement you are trying to model?

Best regards,
Paul.

Thanks for replying Paul,

I'm not sure if the suggested solution is possible, since I'm using 30 years of hourly price data of energy market and multiple ancillary services.

I am doing a masters thesis about techno-economic analysis of PV-BESS systems of different size configurations and enrgy/ancillary market contributions to find out the most profitable combination of PV-BESS in the Swedish market through comparing the resulted NPV, LCOE, IRR at the end.
I'm half way through and noticed that the LCOE factor is not changing that much when I deactivate the energy market, and only use a single/multiple ancillary service market as a mean of revenue.

When using only ancillary market revenues and looking into "Electricity to grid from system AC (kW)", I can see that the PV system is generating an selling power to the grid in return for the ancillary market prices; in case of considering extracting the "Electricity to grid from battery AC (kW)" data to do exteranl calculations, it will lead to inaccuracies, since SAM has modelled the whole system which affects the O&M costs, battery cycling, and the energy yield.

Was this kind of simulation possible in older versions?

I hope I gave enough details for you to understand my simulation purposes.