Model Results

2 posts / 0 new
Last post
Variation in power output on a PV system

I have downloaded SAM and work on design in India.
When i make a selection for PV commercial model, what i want is :
1 I use TMY files. I am not able to do 1:1 AC to DC ratio. if i do, it obviously tells the inverter power is under utilized. what to do if i want 1:1 ratio ??
2 What is the general ball park variation in output between SAM, PVSyst and Actual for a specific location ??

2 posts / 0 new
Last post
Run SAM simulation from command line

I have a use case to run batch SAM simulations. To do this I have an external controller to change parameters that will either interface with the SAM scripts, or command line args.
I want to be able to run my simulation after I have generated the code from the SAM UI and interfaced the code with my parametric controller software. I have a few questions:

2 posts / 0 new
Last post
3D Shade Calculator with microinverters/many strings

Hi there,

I'm often modelling microinverter Solar PV arrays and therefore have many strings associated with each subarray. E.g. 20 module system with 2 subarrays, each with 10 strings in parallel (1 module and 1 micro per string) for a total of 20 strings.

To properly model this with the 3D Shade Calculator, would I have to create 36 uniquely placed (x,y) active surfaces? Due to the limit of 8 strings per subarray, to do this, I would have to break the main array into 3 subarrays: 2x8 strings and 1x4 strings or something similar.

2 posts / 0 new
Last post
Extrapolating coefficients from other power classes

I'm currently using the IEC61853 Single Diode Model in SAM to simulate solar systems, and I'm using laboratory test data from different manufacturers to calculate the coefficients, e.g. C1, C2, C3, Diode factor, etc. Some of the manufacturers I'm working with haven't done the IEC 61853 multi-irradiance testing on every power class, so they'll give me results for 320W panels when we'd also like to simulate 315W, and 325W panels from the same product line.

2 posts / 0 new
Last post
The AC inverter power(W) is 0

Hi everyone,

I tried the PVWatts(Residential) module to produce solar generation data using 1-minute time resolution weather data. PVWatts did not remind me of any error. However, the AC inverter power is 0. The default parameters in System Design was selected. I tried to attach weather data but failed. Part of the data is as follows. Did you encounter this problem?

2 posts / 0 new
Last post
Basics of the solar profile

In the "normalized shape" column I don't understand how the formulas lead to the values in the column. For example, in row 20, it has a value of .24. I don't understand from the formula how it actually calculates that from the INDEX and MATCH functions included within the formula. I've looked up same in Excel but I don't see how/why it grabbed that value of .24.

Also, I don't know why the normalized shape section, only lists 1,235 kWhs and the rooftop shape lists 4,941 kWhs. I understand the value in the CDG shape column.

2 posts / 0 new
Last post
Location and Interval Load Data Errors

Hi Guys,

I've gone through your webinars and followed your steps pretty closely. I'm getting a bunch of errors when I go to run a simple PVWatts, commercial simulation. I believe the errors are caused by two of my own inputs, as when I use the inbuilt inputs I do not get the same errors.

2 posts / 0 new
Last post
Data Table (SAM UX) and the SDK variables


what's the SDK's variable name for 'Array DC power'(hourly Data)?

Is there any table that's linked between the Data Table (SAM UX) and the SDK variables?


3 posts / 0 new
Last post
Possible bug with net billing

I'm wondering if there's a bug in net billing.

I'm trying to verify that SAM is modeling my electricity bill correctly, but I haven't been successful yet. Particularly I'm seeing surprising results with the monthly "Excess generation credit $ earned" value. I thought I could verify that the credit $ earned is being calculated correctly by comparing it to "Excess generation kWh credit earned" x sell rate, and indeed it matches perfectly, for any month in which "Electricity to/from grid" is negative, but not if it's positive. See the attached screenshot.

2 posts / 0 new
Last post
LCOE inconsistency, Cash Flow

Hi, I'm simulating a 100 MW central receiver CSP plant (without TES). In the "Summary" of results, SAM tells me that the resulting nominal LCOE is 26.02 cents / kwh, which coincides with the information shown in the "Cash Flow" tab. However, if I check the detail of the cash flow with the "Send to Excel with Equations" tool, it turns out that the nominal LCOE shown is 29.44 cents / kwh.

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer