Simply More Energy
SAM How-To
SAM Version 2016.3.14
Revolutionary Solar Energy Systems
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Overview
• In this How To guide you will be walked through the key assumptions necessary to
model the energy output of a Ten K Solar PV array using the US National Renewable
Energy Lab’s (NREL) System Advisor Model (SAM).
• SAM is a complex program that incorporates many options for modelling renewable
energy. What is shown here are the necessary variables to model estimated energy
production for Ten K Solar PV systems without storage.
• SAM also provides the ability for financial modelling, but that subject is not
addressed here.
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Why SAM?
• Various tools, such as PV Watts or PVSyst are used to model the energy production
of PV systems, taking into account the climate where the system is installed, the size
of the system and the technology used.
• The Ten K Solar PV systems cannot be accurately modelled with these tools for two
reasons:
 The Ten K Solar REFLECT system uses static reflection in a way unlike any
other PV product. Attempting to generate energy production estimates from
tools like PVWatts or PVSyst using standard PV assumptions will yield
inaccurate results.
 Both the Ten K Solar REFLECT system and DUO system employ modules with
independent cell architecture and do not use bypass diodes. Additionally the
modules include power electronics that perform MPPT internally at the cell
level. Modelling tools other than SAM cannot accurately reflect these
differences from conventional PV.
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Background on SAM
• SAM promotes the use of a consistent methodology for analysis across all solar
technologies
• SAM allows users to investigate the impact of variations in physical, cost, and
financial parameters to better understand their impact on key figures of merit.
Figures of merit related to the cost and performance of these systems include, but
aren't limited to:
 System output
 Hourly system production
 Peak and annual system efficiency
 Levelized cost of electricity
 System capital and operating and maintenance (O&M) costs
• More information about SAM can be found at https://sam.nrel.gov/
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SAM version
• NREL typically releases an updated version of SAM twice per year.
• To maintain synchronization with assumptions and practices of Ten K Solar’s system
design, Ten K Solar currently uses SAM version 2016.3.14
 This can be downloaded from https://sam.nrel.gov/content/downloads
 You will be required to create a user account at NREL to download the
program.
• Ten K Solar will issue an update to this document when the qualification of any
newer version of SAM is completed.
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Benefit of Using NREL’s SAM
• Provides for consistent comparison between differing technologies
• Use of a 3rd party software
• Ability to model practically unlimited locations
• Maintains pace with other developments in solar industry modeling
• Provides an equivalent energy estimate to other leading PV energy modeling tools
• Note: You can easily model conventional PV systems in SAM as well. See SAM Help
for the straightforward steps to do this.
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System Applicability
• This guide describes how to model the energy output for the Ten K Solar DUO
utilizing Ten K Solar’s XT-A 440W (Titan) module, and REFLECT PV systems
utilizing Ten K Solar’s XT-A 410W (Titan) module.
REFLECT - More Energy
Per Watt
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DUO - Ultra High Power Density;
Most Energy Per Roof
Ready made templates
• Ten K Solar has created SAM templates for your use. There are sets for each of the
REFLECT 26, REFLECT 28, and DUO systems.
 Each set includes templates for array azimuths varying from 135° to 225° in 5°
increments.
 DUO template sets also include templates for array azimuths from 230° to
270°.
• It is highly recommended you start by using these templates to model your system
output, and use them as a guide to understand the operation of the models and
how to make appropriate changes for your specific projects.
• These templates are available at TenKSolar.com > Support > System Design > SAM
Templates
• These templates are guidelines. You need to ensure the assumptions used in them
are relevant for your project.
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Modeling your array
• Select the template that corresponds to:
 The Ten K Solar system type you will be modelling:
 REFLECT 26
 REFLECT 28
 DUO; and
 The azimuth of your array.
 If your array azimuth is not an exact multiple of 5°, use the template for
the next increment of 5° further away from due south. Thus if your array
azimuth is 197°, select the template for 200°.
• If you have already downloaded the 2016.3.14 version of SAM, just double click on
the template you select and it will open in SAM. (Note: These templates will not
open in SAM 2015.6.30, or earlier versions.)
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SAM Template Inputs
• Most of the input values for the Ten K Solar PV systems are pre-loaded in the SAM
templates. For reasons behind these values, see Appendix.
• The next section of this presentation will focus on the values you will need to input
in order to model your particular array.
• When you first open the template you have selected, it will open to the Location and
Resource page – see next slide.
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Location and Resource Page
SAM will open to
the Location and
Resource Page.
You can
download a TMY
file for any
location by
name, zip code,
or coordinates.
Or, type the
name of the
desired city into
the search box.
And select the
weather file you
want to use.
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Module Page
Click on the
Module Page.
It comes preloaded with the
correct values to
model the Ten K
Solar module for
the template you
have selected (In
this case the 440W
Apex module, as
indicated in the
title of the
template).
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Inverter Page
Click on the Inverter
Page.
Type the name of
the inverter
manufacturer into
the search box.
Select the inverter
that is used on the
inverter buses in
your array.
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System Design Page (1)
Click on the System
Design Page.
Because Ten K Solar
modules are wired in
parallel, “Modules per
string” will always be 1.
Enter the total number
of modules in your array
in the “Strings in
parallel” box.
Enter the total number
of inverters on all of the
inverter buses in your
array into the “Number
of inverters” box.
Typically Ten K Solar
inverter buses have
either 6 or 12 inverters
on each inverter bus.
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System Design Page (2)
Stay on the System
Design Page.
Enter a value into the
Strings allocated to
Subarray 2 box.
The value to enter will
depend on whether your
system is DUO or
REFLECT.
If it is a DUO system,
enter half of the number
you entered in “Strings in
parallel.”
If it is a REFLECT 26 or
REFLECT 28 system, enter
the number of modules in
your array that have
another module directly
in front of them.
SAM will calculate the
Strings allocated to
Subarray 1.
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Shading and Snow Page (1)
Click on the
Shading and
Snow Page.
For most arrays,
you will not have
to enter any
data on this
page.
However, if you
have any serious
shading on part
of your array,
you can click on
the “Open 3D
shade
calculator…”
button.
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Shading and Snow Page (2)
This will open SAM’s
3D shading calculator
tool.
It allows you to draw
representations of
your array and of
shading obstacles
nearby.
SAM will then create a
table of shading values
that will be added to
the shading values
already in the Ten K
Solar SAM templates.
SAM will use these
shading tables in its
energy production
calculations.
See the Shading
calculator’s Help
section for instructions
on using this tool.
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Losses Page (1)
Click on the Losses
page.
The Ten K Solar SAM
templates are
preloaded with 3%
annual soiling, at 3%
each month. This may
not reflect snow or
other conditions that
are geographically
specific to your array.
To change these
values based on your
expectations for your
array, click on the Edit
Values button for
Subarray 1.
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Losses Page (2)
The Edit Values
dialog box will
open and you can
change the soiling
values on a nonuniform month by
month basis.
Or you can enter a
single value that
will be applied
uniformly to each
month. Click Apply
after entering your
value, and click OK.
Repeat the process
for Subarray 2.
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Losses Page (3)
The DC Losses
fields are prepopulated with
appropriate
values. You should
not need to alter
these. LID is
accounted for in
Nameplate.
The 2% AC losses
is a generic
assumption. Your
system may have
higher or lower AC
losses. Adjust the
values in this
section for your
specific system as
needed.
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Simulate Energy Production (1)
Once the
values in the
previously
noted pages
have been
appropriately
entered, click
Simulate.
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Simulate Energy Production (2)
SAM will bring you to
the Summary screen.
(If not, click on
Summary.) This
screen will show
basic output
simulation data.
Other top menu
selections will
provide a wide range
of calculated data.
See SAM Help to
guide you regarding
the various options.
Note that the
financial output will
not be accurate
unless you have
entered accurate data
in SAM’s financial
input pages. See
SAM’s Help pages.
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Appendix – Preloaded Values
• The various SAM parameters that characterize the Ten K Solar PV system are derived
from data from a National Renewable Energy Laboratory test array. Ten K Solar has
developed a white paper that details the conclusions. You can find it on our website
at: TenKSolar.com > Support > White Papers > Energy Model Accuracy
• The white paper shows the correlations using an earlier version of SAM. The same
parameters are in the current version, but may be located on different pages than in
the old version.
• The NREL test used an older generation of the Ten K Solar PV system (XN), so some
parameters values have been adjusted for the current generation. For example, with
the XN system’s larger reflector, there was a diffuse light gain of 8%. With today’s
system with a smaller reflector (REFLECT systems) or no reflector (DUO systems),
there is no diffuse light gain, and that is reflected in the Sky Diffuse Shading Factor
values in the current templates.
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Simply More Energy
Thank You
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