Merge pull request #8275 from NREL/sam_pvwatts

Update PVWatts using SAM Simulation Core library

CMakeLists.txt

@@ -188,6 +188,7 @@ INCLUDE_DIRECTORIES( ${PROJECT_SOURCE_DIR}/third_party/Windows-CalcEngine/src/Si
 INCLUDE_DIRECTORIES( ${PROJECT_SOURCE_DIR}/third_party/Windows-CalcEngine/src/SpectralAveraging/include)
 INCLUDE_DIRECTORIES( ${PROJECT_SOURCE_DIR}/third_party/Windows-CalcEngine/src/Tarcog/include)
 INCLUDE_DIRECTORIES( ${PROJECT_SOURCE_DIR}/third_party/Windows-CalcEngine/src/Viewer/include)
+INCLUDE_DIRECTORIES( ${PROJECT_SOURCE_DIR}/third_party/ssc )
 if( OPENGL_FOUND )
     INCLUDE_DIRECTORIES( ${PROJECT_SOURCE_DIR}/third_party/penumbra/include )
 endif()
@@ -249,6 +250,37 @@ ENDIF()
 ADD_SUBDIRECTORY(third_party/Windows-CalcEngine)
 set_target_properties(Windows-CalcEngine PROPERTIES FOLDER ThirdParty/Windows-CalcEngine)
 
+# SAM Simulation Core (SSC)
+mark_as_advanced(FORCE JSONCPP_USE_SECURE_MEMORY)
+mark_as_advanced(FORCE JSONCPP_WITH_CMAKE_PACKAGE)
+mark_as_advanced(FORCE JSONCPP_WITH_EXAMPLE)
+mark_as_advanced(FORCE JSONCPP_WITH_PKGCONFIG_SUPPORT)
+mark_as_advanced(FORCE JSONCPP_WITH_STRICT_ISO)
+mark_as_advanced(FORCE JSONCPP_WITH_TESTS)
+set(JSONCPP_WITH_TESTS OFF CACHE BOOL "Compile and (for jsoncpp_check) run JsonCpp test executables" FORCE)
+mark_as_advanced(FORCE JSONCPP_WITH_WARNING_AS_ERROR)
+mark_as_advanced(FORCE DEBUG_LIBNAME_SUFFIX)
+mark_as_advanced(FORCE JSONCPP_WITH_POST_BUILD_UNITTEST)
+set(JSONCPP_WITH_POST_BUILD_UNITTEST OFF CACHE BOOL "Automatically run unit-tests as a post build step" FORCE)
+mark_as_advanced(FORCE CCACHE_FOUND)
+set(SAM_SKIP_TOOLS ON CACHE BOOL "Skips the sdktool and tcsconsole builds" FORCE)
+mark_as_advanced(FORCE SAM_SKIP_TOOLS)
+set(SAM_SKIP_TESTS ON CACHE BOOL "Skips building tests" FORCE)
+mark_as_advanced(FORCE SAM_SKIP_TESTS)
+set(SAMAPI_EXPORT OFF CACHE BOOL "Export of ssc binaries to the SAM_api directory; for Unix, compile ssc libraries for SAM_api" FORCE)
+mark_as_advanced(FORCE SAMAPI_EXPORT)
+ADD_SUBDIRECTORY(third_party/ssc)
+set_target_properties(ssc PROPERTIES FOLDER ThirdParty/ssc)
+IF ( CMAKE_COMPILER_IS_GNUCXX OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "AppleClang"  ) # g++/Clang
+  target_compile_options(splinter PUBLIC -Wno-error -w)
+  target_compile_options(shared PUBLIC -Wno-error -w)
+  target_compile_options(ssc PUBLIC -Wno-error -w)
+ELSEIF( MSVC ) # VisualStudio
+  target_compile_options(splinter PUBLIC /W0)
+  target_compile_options(shared PUBLIC /W0)
+  target_compile_options(ssc PUBLIC /W0)
+ENDIF()
+
 # Btwxt
 INCLUDE_DIRECTORIES( ${gtest_SOURCE_DIR}/include/ SYSTEM )
 set(BUILD_BTWXT_TESTING ${BUILD_TESTING} CACHE BOOL "" FORCE)

doc/input-output-reference/src/overview/group-electric-load-center-generator.tex

@@ -4762,7 +4762,7 @@ \subsubsection{Inputs}\label{inputs-22}
 
 \subsection{Generator:PVWatts}\label{generatorpvwatts}
 
-PVWatts is a web application and module in NREL's System Advisor Model (SAM) software that estimates the electricity production of a grid-connected photovoltaic system based on a few simple inputs. This object brings the same calculations from PVWatts into an EnergyPlus whole building simulation without the need to call the web application API or SAM SDK. It provides a good alternative to the \hyperref[generatorphotovoltaic-000]{Generator:Photovoltaic} object when detailed information about the PV array is not available such as in a first pass analysis or when the desire is to achieve comparable results to PVWatts outside of EnergyPlus. To get comparable results to PVWatts, it should be used with the \hyperref[electricloadcenterinverterpvwatts]{ElectricLoadCenter:Inverter:PVWatts}.
+PVWatts is a web application and module in NREL's System Advisor Model (SAM) software that estimates the electricity production of a grid-connected photovoltaic system based on a few simple inputs. This object brings the same calculations from PVWatts into an EnergyPlus whole building simulation without the need to call the web application API or SAM SDK. It provides a good alternative to the \hyperref[generatorphotovoltaic-000]{Generator:Photovoltaic} object when detailed information about the PV array is not available such as in a first pass analysis or when the desire is to achieve comparable results to PVWatts outside of EnergyPlus. To get comparable results to PVWatts, it should be used with the \hyperref[electricloadcenterinverterpvwatts]{ElectricLoadCenter:Inverter:PVWatts}. The PVWatts:Generator uses SAM 2020.11.29 Revision 0, SSC Revision 250.
 
 \subsubsection{Inputs}\label{input-description}
 
@@ -4908,6 +4908,8 @@ \subsubsection{Outputs Description}\label{outputs-description}
   HVAC,Average,Plane of Array Irradiance $\left [\frac{\text{W}}{\text{m}^2} \right ]$
 \item
   HVAC,Average,Generator PV Cell Temperature {[}C{]}
+\item
+  HVAC,Average,Shaded Percent {[}\%{]}
 \end{itemize}
 
 

src/EnergyPlus/CMakeLists.txt

@@ -452,8 +452,6 @@ SET( SRC
   OutsideEnergySources.hh
   PVWatts.cc
   PVWatts.hh
-  PVWattsSSC.cc
-  PVWattsSSC.hh
   PackagedTerminalHeatPump.cc
   PackagedTerminalHeatPump.hh
   PackagedThermalStorageCoil.cc
@@ -778,7 +776,7 @@ endif()
 # first we will create a static library of EnergyPlus
 # this will be linked statically to create the DLL and also the unit tests
 add_library( energypluslib STATIC ${SRC} )
-target_link_libraries( energypluslib fmt::fmt objexx sqlite bcvtb epexpat epfmiimport re2 DElight libkiva btwxt Windows-CalcEngine airflownetworklib )
+target_link_libraries( energypluslib fmt::fmt objexx sqlite bcvtb epexpat epfmiimport re2 DElight libkiva btwxt Windows-CalcEngine airflownetworklib ssc )
 if (OPENGL_FOUND)
   target_link_libraries( energypluslib penumbra )
 endif()

src/EnergyPlus/ElectricPowerServiceManager.cc

@@ -943,6 +943,10 @@ ElectPowerLoadCenter::ElectPowerLoadCenter(EnergyPlusData &state, int const obje
                 } else {
                     PVWatts::PVWattsGenerator &pvwGen = PVWatts::GetOrCreatePVWattsGenerator(state, generatorController->name);
                     totalDCCapacity += pvwGen.getDCSystemCapacity();
+
+                    // Pass the inverter properties to the PVWatts generator class
+                    pvwGen.setDCtoACRatio(inverterObj->pvWattsDCtoACSizeRatio());
+                    pvwGen.setInverterEfficiency(inverterObj->pvWattsInverterEfficiency());
                 }
             }
             if (!errorsFound) {
@@ -2503,6 +2507,16 @@ Real64 DCtoACInverter::pvWattsDCCapacity()
     return ratedPower_ * pvWattsDCtoACSizeRatio_;
 }
 
+Real64 DCtoACInverter::pvWattsInverterEfficiency()
+{
+    return pvWattsInverterEfficiency_;
+}
+
+Real64 DCtoACInverter::pvWattsDCtoACSizeRatio()
+{
+    return pvWattsDCtoACSizeRatio_;
+}
+
 Real64 DCtoACInverter::thermLossRate() const
 {
     return thermLossRate_;
@@ -2601,6 +2615,9 @@ void DCtoACInverter::calcEfficiency(EnergyPlusData &state)
         break;
     }
     case InverterModelType::pvWatts: {
+        // This code is lifted from ssc cmod_pvwatts5.cpp:powerout() method.
+        // It was easier to do this calculation here because we have a many to one relationship between inverter
+        // and generator whereas theirs is one to one.
         Real64 const etaref = 0.9637;
         Real64 const A = -0.0162;
         Real64 const B = -0.0059;
@@ -2617,6 +2634,8 @@ void DCtoACInverter::calcEfficiency(EnergyPlusData &state)
                 // clipping
                 ac = ratedPower_;
             }
+            // make sure no negative AC values (no parasitic nighttime losses calculated)
+            if (ac < 0) ac = 0;
             efficiency_ = ac / dCPowerIn_;
         } else {
             efficiency_ = 0.0;

src/EnergyPlus/ElectricPowerServiceManager.hh

@@ -113,6 +113,10 @@ public: // Methods
 
     Real64 pvWattsDCCapacity();
 
+    Real64 pvWattsInverterEfficiency();
+
+    Real64 pvWattsDCtoACSizeRatio();
+
     Real64 thermLossRate() const;
 
     Real64 getLossRateForOutputPower(EnergyPlusData &state, Real64 const powerOutOfInverter);