Hourly Sales Not Reporting Correctly?

Hi Paul,

It appears that the variables "Year 1 hourly sales/purchases with system ($)" and "Year 1 hourly sales/purchases without system ($)" are not working as anticipated when Net Metering is enabled. I would expect these variables to report how much the utility it charging a customer for each hour (regardless of whether that customer is importing or exporting electricity). Rather, it seems that SAM is zeroing out all variables within the month and reporting the sum (the monthly bill) in the final hour within each month when Net Metering is enabled.

Is this how those variables are supposed to function? If so, are there other variables that can be used in the way I originally thought these ones should have behaved?

Thanks,

Nathan Clark

Dear Nathan,

Your observation is correct. When you enable Net Metering on the Utility Rate page, SAM does the accounting calculations on a monthly basis, and shows the monthly sales/purchases with and without system values in the hourly results as monthly totals in the last hour of each month.

The "Year 1 electricity to/from grid (kWh)" output variable shows the hourly flow of kWh to and from the grid. Because the value of electricity depends on the relationship between the total monthly load and the total monthly system output, the model does not know what the value of electricity is as it steps through the hourly simulations.

Best regards,
Paul.