Electricity bill without solar (year 1)

Hello- I have loaded my utility rate file from SAM, eg., Pacific Gas & Elec, E1 (non time-of-use) residential. The tiered prices look correct.

Next, I loaded my actual monthly loads. However, when I run the simulation, the estimated electrical cost without solar is almost exactly 2x my actual cost. What do I need to change? I do have my actual kWh consumption by tier and month.

Also, a little off topic, but is there a way to change the sales tax rate? Thanks

Sales Tax Rate can be changed on the Financial Parameters page.

My understanding is that SAM expects the load data to be in kW, not kWh. You can approximate the relationship between the two based on the periodicity of the data load set by the Edit Data "Change time step" (60 minutes, 30 minutes, 15 minutes). In my case, the utility provided the data in kWh and 15-minute increments so I multiplied kWh's by 4.

I'm not sure if your utility could provide the data in kW instead of kWh but mine could not.

Hi "dklip,"

Did that answer your question? Please follow up if you need any clarification.

Best regards,
Paul.

Hello Paul,

The consumption data I receive from Pacific Gas & Electric is in kWh/hour so I am assuming that the scale factor is 1. When I go to 'Electric Load' and enter my monthly loads, the application (SAM 2016) automatically calculates peak kW. I am not entering any Load information here except for my 12 monthly consumption records in kWh.

Here is where I am not clear; Under 'Electricity Rates' > 'Energy Charges' my rate file displays 5 tiers. How does the application know what tier I am pulling from? For example, I never use tiers 4 or 5, and rarely enter tier 3. Do I need to edit the table 'Rate Structure for Energy Rates'? I'm not sure what the 'Max Useage' header in this table refers to. Thanks, -Dave

Thanks to lwkerber for direction on sales tax.

On the Electric Load page in SAM, when you enter monthly data, SAM scales the data in the underlying hourly data set to match the monthly values you enter. The peak values result from the scaled data. You can see what SAM is doing by clicking the "View load data" button, and displaying both the "user-intered load power" and the "scaled load power" values in the graph. The "user-entered" data is the underlying hourly data, and the "scaled" data is that data adjusted to match the monthly bill totals you entered.

When you use a rate structure with tiered rates on the Electricity Rates page, SAM determines what rate ($/kWh) to apply to each block of kWh by month by looking at the tiered rate structure. For example, suppose the rate structure looks like this:

Tier 1: Max Usage = 100 kWh, Buy Rate = $0.05/kWh
Tier 2: Max Usage = 150 kWh, Buy Rate = $0.08/kWh
Tier 3: Max Usage = 1e+38 kWh, Buy Rate = $0.10/kWh

And, for January the total monthly consumption is 140 kWh. The resulting energy charge for January would be:

100 kWh * $0.05/kWh + 40 kWh * $0.08/kWh kWh = $8.2

Note that Tier 3 is never reached in January because the total consumption is below 150 kWh.

Best regards,
Paul.