Ability to undertake simulations to determine the impact of photovoltaic facades on a building.

Task

Instructions

1. Access a simple exemplar and explore the model.

Return to your home folder and start up ESP-r. From the top level menu, choose open existing and then exemplar options. Select the base case cellular model with PV integrated facade from the technical features category. The model should be copied into your home directory.

In this model, PV modules have been added to the area below the window in the manager a office.

2. Review PV module datasheet.

In another window open up the manufacturer's data sheet (in pdf format). The file is /usr/esru/esp-r/training/cellular_pv/cfg/BP_Solar_380.pdf (or similar file in c:\ESRU\esp-r on Windows machines). Of most interest are the size of the modules and:

• V_oc (open circuit voltage)
• I_sc (short circuit current)
• V_mpp (max power point voltage)
• I_mpp (max power point current)

3. Review the information specific for modelling building integrated photovoltaics.

From the Project Manager menu go to browse/edit/simulate then to composition and then to integrated renewables. The PV modules have already been defined so say yes to the special materials file and accept the default name. Click on the BP380 entry and edit the component. Choose crystalline PV and the BP380 module. Step through the values entered without changing them. When you are asked to select the zone in which to locate the special component (i.e. the PV module), select manager_a, then surface PVmod then layer 2 EVA (node 4) which indicates where in the construction the PV cells are located and generating electrical power. Note how the different specifications in the manufacturer's data sheet are defined in the special materials file and that 5 modules are mounted in the available space under the window.

4. Review the corresponding material and optical properties for the PV module.

In the top level menu for the Project Manager, go to database maintenance. View the entries for the PV modules mounted on the existing wall in the material, construction and optical databases. Note the PV module is a glass, EVA, glass construction.

5. Review the electrical network for the model.

Select networks: electrical from the browse/edit/simulate menu. List the contents of this simple network which links the output from the PV modules to the grid and to the lights in the corridor. Read the help message for basic information on the electrical network definition.

6. Run a simulation for one week and view results.

Run a simulation for the period 6 - 12 February. Choose to look at the electrical results and enter the electrical results database name (/tmp/cellular_pv_win1.libe by default). Graphically display the results. Toggle the Focus >> Nodes to Focus >> Whole network and then select and display Total generation. This will show the power output from the PV modules. To view the total electrical loading select and display Total loading. This will show the loading from the lights (note power draw is negative). Finally look at the interaction between the two by clearing previous selections, then selecting and displaying Total grid import to show the power that needs to be imported from the grid to supply loads after the PV output has been accounted for. To view only the real power flows select Hide/show output and switch off all entries with VAR (the reactive power) in the resulting list, exit and draw the graph again. Notice that in the evenings real power import is +ve indicating power draw from the grid. However, in the middle of the day the value is -ve indicating that there is surplus real power which can be exported.

7. Change the lighting loads.

In the Project Manager, edit the operations file for the corridor zone. At present the lights are 100W on weekdays in working hours (8:00 to 20:00) and 50W at other times. Change the lighting load by, for example, switching off the lights outside working hours, and reduce the lighting load to 50W. Repeat the simulation and results analysis and observe how the imported power from the network has changed.