Merge pull request #5 from NREL/1axis_tracking

1axis tracking critical update
NREL · Mar 21, 2018 · ea1f0be · ea1f0be
2 parents fac4591 + a1d63d8
commit ea1f0be
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Showing 4 changed files with 68 additions and 28 deletions.
diff --git a/bifacial_radiance/bifacial_radiance.py b/bifacial_radiance/bifacial_radiance.py
@@ -633,7 +633,7 @@ def makeOct(self,filelist=None,octname = None):
                     raise Exception, err[7:]
 
         #use rvu to see if everything looks good. use cmd for this since it locks out the terminal.
-        #'rvu -vf views\CUside.vp -e .01 monopanel_test.oct'
+        #'rvu -vf views\side.vp -e .01 monopanel_test.oct'
         print("created %s.oct" % (octname)),
         self.octfile = '%s.oct' % (octname)
         return '%s.oct' % (octname)
@@ -810,8 +810,8 @@ def makeScene1axis(self, trackerdict=None, moduletype=None, sceneDict=None, nMod
                 module_y = scene.y
             elif sceneDict['orientation'] == 'landscape':
                 module_y = scene.x
-            # Calculate the ground clearance height based on the hub height
-            height = hubheight - 0.5* math.sin(theta * math.pi / 180) * module_y
+            # Calculate the ground clearance height based on the hub height. Add abs(theta) to avoid negative tilt angle errors
+            height = hubheight - 0.5* math.sin(abs(theta) * math.pi / 180) * module_y
             radfile = scene.makeSceneNxR(surf_tilt, height,sceneDict['pitch'],orientation = sceneDict['orientation'], azimuth = surf_azm, nMods = nMods, nRows = nRows, radname = radname)
             trackerdict[theta]['radfile'] = radfile
             trackerdict[theta]['scene'] = scene
@@ -1521,7 +1521,7 @@ def analysis(self, octfile, basename, frontscan, backscan, plotflag = False):
 
 if __name__ == "__main__":
     '''
-    Example of how to run a Radiance routine for a simple bifacial system
+    Example of how to run a Radiance routine for a simple rooftop bifacial system
 
     '''
 
@@ -1551,4 +1551,45 @@ def analysis(self, octfile, basename, frontscan, backscan, plotflag = False):
     analysis.analysis(octfile, demo.basename, scene.frontscan, scene.backscan)  # compare the back vs front irradiance  
     print('Annual bifacial ratio: %0.3f - %0.3f' %(min(analysis.backRatio), np.mean(analysis.backRatio)) )
 
+    ''' 
+    Single Axis Tracking example
+    Note: this takes significantly longer than a single simulation!
+    
+    '''
+    print('\n******\nStarting 1-axis tracking example \n********\n' )
+    # tracker geometry options:
+    module_height = 1.7  # module portrait dimension in meters
+    gcr = 0.33   # ground cover ratio,  = module_height / pitch
+    albedo = 0.3     # ground albedo
+    hub_height = 2   # tracker height at 0 tilt in meters (hub height)
+    limit_angle = 45 # tracker rotation limit angle
 
+    # Example 1-axis tracking system using Radiance.  This takes 5-10 minutes to complete, depending on computer.
+
+    demo2 = RadianceObj(path = testfolder)  # Create a RadianceObj 'object' named 'demo'
+    demo2.setGround(albedo) # input albedo number or material name like 'concrete'.  To see options, run this without any input.
+    epwfile = demo2.getEPW(37.5,-77.6) #Pull TMY weather data for any global lat/lon.  In this case, Richmond, VA
+    metdata = demo2.readEPW(epwfile) # read in the weather data
+
+    ## Begin 1-axis SAT specific functions
+    # create separate metdata files for each 1-axis tracker angle (5 degree resolution).  
+    trackerdict = demo2.set1axis(metdata, limit_angle = limit_angle, backtrack = True, gcr = gcr)
+    # create cumulativesky functions for each tracker angle: demo.genCumSky1axis
+    trackerdict = demo2.genCumSky1axis(trackerdict)
+    # Create a new moduletype: Prism Solar Bi60. width = .984m height = 1.695m. 
+    demo2.makeModule(name='Prism Solar Bi60',x=0.984,y=module_height)
+    # print available module types
+    demo2.printModules()
+
+    # create a 1-axis scene using panels in portrait, 2m hub height, 0.33 GCR. NOTE: clearance is calculated at each step. hub height is constant
+    sceneDict = {'pitch': module_height / gcr,'height':hub_height,'orientation':'portrait'}  
+    module_type = 'Prism Solar Bi60'
+    trackerdict = demo2.makeScene1axis(trackerdict,module_type,sceneDict, nMods = 20, nRows = 7) #makeScene creates a .rad file with 20 modules per row, 7 rows.
+    # TODO:  can this 20x7 scene be reduced in size without encountering edge effects?
+    trackerdict = demo2.makeOct1axis(trackerdict)
+    # Now we need to run analysis and combine the results into an annual total.  This can be done by calling scene.frontscan and scene.backscan
+    trackerdict = demo2.analysis1axis(trackerdict)
+
+    # the frontscan and backscan include a linescan along a chord of the module, both on the front and back.  
+    # Return the minimum of the irradiance ratio, and the average of the irradiance ratio along a chord of the module.
+    print('Annual RADIANCE bifacial ratio for 1-axis tracking: %0.3f - %0.3f' %(min(demo2.backRatio), np.mean(demo2.backRatio)) )
diff --git a/bifacial_radiance/data/module.json b/bifacial_radiance/data/module.json
@@ -1 +1 @@
-{"mini_panel": {"orientation": "landscape", "text": "!genbox black PVmodule 0.6096 0.9144 0.012192 | xform -t -0.3048 0 0 ", "bifi": 1, "modulefile": "objects\\mini_panel.rad", "y": 0.9144, "x": 0.6096}, "simple_panel": {"orientation": "portrait", "text": "! genbox black PVmodule 0.95 1.59 0.02 | xform -t -0.475 0 0", "bifi": 1, "modulefile": "objects\\simple_panel.rad", "y": 1.59, "x": 0.95}, "monopanel": {"orientation": "portrait", "text": "", "bifi": 1, "modulefile": "objects\\monopanel_1.rad", "y": 1.59, "x": 0.95}, "Prism Solar Bi60": {"orientation": "portrait", "text": "! genbox black PVmodule 0.984 1.695 0.02 | xform -t -0.492 0 0", "bifi": 0.9, "modulefile": "objects\\Prism_Solar_Bi60.rad", "y": 1.695, "x": 0.984}}
+{"mini_panel": {"orientation": "landscape", "text": "!genbox black PVmodule 0.6096 0.9144 0.012192 | xform -t -0.3048 0 0 ", "bifi": 1, "modulefile": "objects\\mini_panel.rad", "y": 0.9144, "x": 0.6096}, "simple_panel": {"orientation": "portrait", "text": "! genbox black PVmodule 0.95 1.59 0.02 | xform -t -0.475 0 0", "bifi": 1, "modulefile": "objects\\simple_panel.rad", "y": 1.59, "x": 0.95}, "monopanel": {"orientation": "portrait", "text": "", "bifi": 1, "modulefile": "objects\\monopanel_1.rad", "y": 1.59, "x": 0.95}, "Prism Solar Bi60": {"orientation": "portrait", "text": "! genbox black PVmodule 0.984 1.7 0.02 | xform -t -0.492 0 0", "bifi": 0.9, "modulefile": "objects\\Prism_Solar_Bi60.rad", "y": 1.7, "x": 0.984}}
diff --git a/docs/1Axis_tracking_example.ipynb b/docs/1Axis_tracking_example.ipynb
@@ -42,15 +42,19 @@
    },
    "outputs": [],
    "source": [
-    "testfolder = r'E:\\Documents\\Python Scripts\\Test1axisFolder'  #point to an empty directory or existing Radiance directory"
+    "#testfolder = r'E:\\Documents\\Python Scripts\\Test1axisFolder'  #point to an empty directory or existing Radiance directory\n",
+    "# tracker geometry options:\n",
+    "module_height = 1.7  # module portrait dimension in meters\n",
+    "gcr = 0.33   # ground cover ratio,  = module_height / pitch\n",
+    "albedo = 0.3     # ground albedo\n",
+    "hub_height = 2   # tracker height at 0 tilt in meters (hub height)\n",
+    "limit_angle = 45 # tracker rotation limit angle"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "name": "stdout",
@@ -159,34 +163,29 @@
     "except ImportError:\n",
     "    raise RuntimeError('bifacial_radiance is required. download distribution')\n",
     "    # Simple example system using Radiance.\n",
-    "#import easygui  # this is only required if you want a graphical directory picker.  Note:  easygui sometimes opens in the background forcing you to hunt for the window!  \n",
-    "#testfolder = easygui.diropenbox(msg = 'Select or create an empty directory for the Radiance tree',title='Browse for empty Radiance directory')\n",
+    "import easygui  # this is only required if you want a graphical directory picker.  Note:  easygui sometimes opens in the background forcing you to hunt for the window!  \n",
+    "testfolder = easygui.diropenbox(msg = 'Select or create an empty directory for the Radiance tree',title='Browse for empty Radiance directory')\n",
     "\n",
     "demo = RadianceObj(path = testfolder)  # Create a RadianceObj 'object'\n",
-    "\n",
-    "demo.setGround(0.2) # input albedo number or material name like 'concrete'.  To see options, run this without any input.\n",
-    "\n",
-    "epwfile = demo.getEPW(37.5,-77.6) #Pull TMY data for any global lat/lon\n",
-    "    \n",
+    "demo.setGround(albedo) # input albedo number or material name like 'concrete'.  To see options, run this without any input.\n",
+    "epwfile = demo.getEPW(37.5,-77.6) #Pull TMY data for any global lat/lon. In this case, Richmond, VA\n",
     "metdata = demo.readEPW(epwfile) # read in the weather data\n",
     "\n",
     "# create metdata files for each condition\n",
-    "trackerdict = demo.set1axis(metdata, limit_angle = 45, backtrack = True, gcr = 1.0/3.0)\n",
+    "trackerdict = demo.set1axis(metdata, limit_angle = limit_angle, backtrack = True, gcr = gcr)\n",
     "\n",
     "# new gencumulativesky function: demo.genCumSky1axis\n",
     "trackerdict = demo.genCumSky1axis(trackerdict)\n",
     "# Create a new moduletype: Prism Solar Bi60. width = .984m height = 1.695m. Bifaciality = 0.90\n",
-    "demo.makeModule(name='Prism Solar Bi60',x=0.984,y=1.695,bifi = 0.90)\n",
+    "demo.makeModule(name='Prism Solar Bi60',x=0.984,y=module_height)\n",
     "# print available module types\n",
     "demo.printModules()\n"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": 3,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "name": "stdout",
@@ -255,7 +254,7 @@
    ],
    "source": [
     "# create a scene using panels in portrait, 2m hub height, 0.33 GCR. NOTE: clearance needs to be calculated at each step. hub height is constant\n",
-    "sceneDict = {'pitch':1.7*3,'height':2,'orientation':'portrait'}  \n",
+    "sceneDict = {'pitch':module_height / gcr,'height':hub_height,'orientation':'portrait'}  \n",
     "module_type = 'Prism Solar Bi60'\n",
     "trackerdict = demo.makeScene1axis(trackerdict,module_type,sceneDict, nMods = 20, nRows = 7) #makeScene creates a .rad file with 20 modules per row, 7 rows.\n",
     "\n",
@@ -265,7 +264,7 @@
     "\n",
     "# the frontscan and backscan include a linescan along a chord of the module, both on the front and back.  \n",
     "# Return the minimum of the irradiance ratio, and the average of the irradiance ratio along a chord of the module.\n",
-    "print('Annual bifacial ratio for 1-axis tracking: %0.3f - %0.3f' %(min(demo.backRatio), np.mean(demo.backRatio)) )\n",
+    "print('Annual RADIANCE bifacial ratio for 1-axis tracking: %0.3f - %0.3f' %(min(demo.backRatio), np.mean(demo.backRatio)) )\n",
     "\n"
    ]
   },
@@ -301,11 +300,11 @@
     "# new gencumulativesky function: demo.genCumSky1axis\n",
     "demo.genCumSky1axis()\n",
     "# Create a new moduletype: Prism Solar Bi60. x = .984 y = 1.695. Bifaciality = 0.90\n",
-    "demo.makeModule(name='Prism Solar Bi60',x=0.984,y=1.695,bifi = 0.90)\n",
+    "demo.makeModule(name='Prism Solar Bi60',x=0.984,y=1.695)\n",
     "# print available module types\n",
     "demo.printModules()\n",
     "# create a scene using panels in portrait, 2m hub height, 0.33 GCR. NOTE: clearance needs to be calculated at each step. hub height is constant\n",
-    "sceneDict = {'pitch':1.7*3,'height':2,'orientation':'portrait'}  \n",
+    "sceneDict = {'pitch':module_height / gcr,'height':hub_height,'orientation':'portrait'}  \n",
     "module_type = 'Prism Solar Bi60'\n",
     "demo.makeScene1axis(moduletype=module_type,sceneDict = sceneDict, nMods = 20, nRows = 7) #makeScene creates a .rad file with 20 modules per row, 7 rows.\n",
     "\n",
@@ -332,7 +331,7 @@
  "metadata": {
   "anaconda-cloud": {},
   "kernelspec": {
-   "display_name": "Python [default]",
+   "display_name": "Python 2",
    "language": "python",
    "name": "python2"
   },
@@ -346,7 +345,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython2",
-   "version": "2.7.12"
+   "version": "2.7.14"
   }
  },
  "nbformat": 4,

diff --git a/setup.py b/setup.py
@@ -30,7 +30,7 @@
     # Versions should comply with PEP440.  For a discussion on single-sourcing
     # the version across setup.py and the project code, see
     # https://packaging.python.org/en/latest/single_source_version.html
-    version='0.1.1',
+    version='0.2.0',
 
     description='Tools to interface with Radiance',
     long_description=long_description,