all hourly data - but an error

Niels,

The error you are seeing is because of the buy rates array in the UI which shows 8760 zeros.
However, the array that is used for the simulation is a single element array with one zero.

To fix the issue, either enter your own array of 8760 buy rates, or:

1. On the Electricity Rates page, click Edit array for hourly/subhourly buy rates.



2. In the Edit Array (Data Array) window, click Change time step.



3. Click OK in the Edit Table and Edit Array (Data Array) windows.

5. Click Simulate, and your case should run without error.



We will fix this issue in the next update to SAM and you can track progress at  github.com/NREL/SAM/issues/343

Thank you!

One question, I entered the site's electricity purchase rate by first selecting the rate that was in the U.S. Utility rate database.. but it was wrong and did not include sales tax, so I edited the rates and the on and off-peak periods.  Do the steps you noted above, have SAM use those purchase rates?

Thank you!

n

Hi Niels,

When you check Use hourly (subhourly) buy/sell rates instead of TOU rates, SAM uses the time series buy and sell rates that you enter in the tables (by clicking Edit array) instead of the buy and sell rates shown in the table under "Energy Charges."

If you want to change rates that originally came from the URDB, you can change them in the Energy Charges table rather than replacing them with time series rates.

Best regards,
Paul.

Thanks Paul! 



But I am still not getting it.

So when the PV project puts power on to the grid, according to the utility's parallel generation tariff, that power is valued on a specific MISO node at its Day-Ahead Hourly Locational Marginal Price (LMP). So I entered the LMPs as the Net Billing Sell Rate.  Initially, I did not enter anything for the Net Billing Buy Rate.  

Instead, I updated the site's electric rate - in the grids provided -  for usage rates and demand charges. You can see this in the attached file.

That did not work, I believe because I did not enter Net Billing Buy Rates.

Sjanzou, had me make some changes/clicks, but I am not sure what really happened. You can see his message above.  I think it put all the Net Billing LMP Sell Rates into the Net Billing Buy Rate  - but I am really not sure.  

If I enter the site's electric rate as the Net Billing Buy Rate - than I miss the demand kW savings value.. as only kWh costs are included in the Buy Rate.

Hi Niels,

When you choose the "Net billing" option,



and check Use hourly (subhourly) buy/sell rates instead of TOU rate,



the energy charge table is disabled, which is why the buy and sell rate columns disappear from the table when you check the box.



So, for your application, you need to click Edit array under "Metering and Billing" for both sell and buy rates to specify the rates using the column of time series values instead of the tables under "Energy Charges."

For demand charges, you can specify those under "Demand Charges." SAM calculates the energy charge and demand charge separately, so you should see the effect of the energy charge buy and sell and demand rates in the monthly bill.



Best regards,
Paul.

For the next update to SAM 2020.2.29, we have added separate check boxes to enable time series buy and sell rates. This will make it possible to specify time series sell rates while using time-of-use buy rates from the energy charges rate table:

github.com/NREL/SAM/issues/343

We hope to release this update to Revision 3 of SAM 2020.2.29 by the end of July 2020.

Best regards,
Paul.