SITE VARIABLES INPUTS
Module Size
 
Pole Mount Model
MT Solar LLC:
Select the number of solar panels you plan to install
 (Number of Modules)
Desired Tilt Angle in Degrees
MT Solar LLC:
90 degrees is vertical. Steeper tilts reduce snow load but increase wind load.
(90 degrees is vertical)
Front Edge Ground Clearance (ft.)
MT Solar LLC:
Higher clearance will increase your foundation depth and may increase your pole size required.
(At tilt angle)
Wind Speed
MT Solar LLC:
Wind Speed is determined by location. Most solar arrays are Risk Category 1 since they are not installed where failure would hurt people. Most local building officials refer to higher wind speeds that are Risk Category 2 (structures over people). Consult an engineer for more information.
  
Exposure Category
MT Solar LLC:
Exposure B. Shall be assumed unless the site meets the definition of another type of exposure. Urban and suburban areas, wooded areas or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger.

Exposure C. Open terrain with scattered obstructions, including surface undulations or other irregularities, having heights generally less than 30 feet (9144 mm) extending more than 1,500 feet (457.2) from the building site in any quadrant. This exposure shall also apply to any building located within Exposure B-type terrain where the building is directly adjacent to open areas of ExposureC-type terrain in any quadrant for a distance of more than 600 feet (182.9 m). This category includes flat open country, grasslands and shorelines in hurricane-prone regions.

Exposure D. Flat, unobstructed areas exposed to wind flowing over open water (excluding shorelines in hurricane-prone regions) for a distance of at least 1 mile (1.61 km). Shorelines in Exposure D include inland waterways, the Great Lakes and coastal areas of California, Oregon, Washington and Alaska. This exposure shall apply only to those buildings and other structures exposed to the wind coming from over the water. Exposure D extends inland from the shoreline a distance of 1,500 feet (460 m) or 10 times the height of the building or structure, whichever is greater.
  
Calculated Snow Load (PSF)
MT Solar LLC:
Depending on your local official, you may be allowed 50% or greater deductions off ground snow load due to snow sliding off the array. Consult an engineer for more information.
(Does not auto reduce for tilt.)
A reduction of ground snow load may be allowable due to snow sliding off of array.
Foundation Shape Desired
 
Foundation Size Desired (ft.)
Site Soil Classification Code
MT Solar LLC:
Many locations are Soil Class 3. You may be able to reduce your soil class by consulting a local Geotechnical Engineer to sample your soil instead of using the IBC classifications listed here.

1 - Crystaline Bedrock
2 - Sedimentary and Foliated Rock
3 - Sandy Gravel and/or Gravel
4 - Sand, Silty Sand, Clayey Sand, Silty Gravel, and Clayey Gravel
5 - Clay, Sandy Clay, Silty Clay, Clayey Silt, Silt, and Sandy Silt
  
Pole Size Desired
(select "Auto Calc" for best results)
OUTPUTS
Number of Poles  
Support Pole Size Required  
Mount Frame Duty  
 Spin Prevention Bolts Needed  
Foundation Depth Required (ft.) Ft. DEEP
Pole Height Above Grade Ft.
FORCES
Calculated Wind Load on Array lbs.
Force at Ground Level (Wind Load x Pole Length)
(Picture the pole as a lever arm, the wind applies the force and the pole tries to move the dirt to lean over)
Rotational Twist/Torque (Single Pole) ft-lbs.
Calculated Snow Load on Array lbs.
     
Conversational OUTPUT
Copyright 2017 MT Solar LLC, All Rights Reserved.
Calculations based on ASCE 7-10 and IBC 2012
All information for project estimation purposes only. 
         
WIND FORCE CALCULATIONS  
Array N/S Dimensions (ft.) ft    
Array E/W Dimensions (ft.) ft B  
Total Square Feet of Array sq/ft    
Tilt Angle in Radians       
Effective Vert Dimension at Tilt Angle (ft.) ft s  
Effective Horizontal Dimension at Tilt Angle (ft.) ft    
Effective Squ Ft. at Tilt Angle sq/ft As  
Total Array Height at Tilt Including Clearance (ft.) ft h  
Simple Wind PSF  psf    
Simple Wind Force Total  lb/ft    
Height/Exposure Coefficient  ASCE 7-10 29.3-1    Kz  
Terrain Coefficient 1.00   Kzt  
Wind Directionality Factor  ASCE 7-10 26.6-1 0.85   Kd  
Wind Force PSF (Qz) lb/ft Qz  
Gust Factor  ASCE 7-10 26.9.1 0.85   G  
Ratio s/h    
Ratio B/s    
Force Coefficient Cf  ASCE 7-10 29.4-1   Cf  
Effective Wind Load PSF      
Effective Wind Total Force on Array (Case A)   F  
Offset Wind Loading Force (Case B) ft-kips    
Effective Wind Total Force Per Pole (Case A)      
Snow Load Total Vertical Force on Array (lbs.)      
Snow Load Total Vertical per Pole (lbs.)      
         
FOUNDATION DEPTH CALCULATIONS  
Force Per Pole ( at Top of Pole) lbs. Pe  
Pole Height Above Grade ft H  
Site Soil Lateral Bearing Capacity psf Pba  
Site Soil Vertical Bearing Capacity psf    
Vertical Bearing Area of Hole squ. ft.   
Max Vertical Bearing Capacity lbs.    
Hole Dimension ft. b  
Allowable Lateral Soil Pressure   S1  
Variable   A  
Foundation Depth Required (ft.) ft. L  
         
         
Copyright 2017 MT Solar LLC, All Rights Reserved.
Calculations based on ASCE 7-10 and IBC 2012
All information for project estimation purposes only.