Waterfall graphs (CSP only) |  |  |  |

| This topic describes SAM 3.0 and has not been revised for SAM 2009 Beta. You may find useful information, especially if you are new to SAM, but some of the information may be inconsistent with the new version.

A waterfall graph displays groups of related variables for comparison. For concentrating solar power systems (parabolic trough, dish-Stirling, and power tower), the data viewer displays a set of variables designed for creating water fall graphs on the Hourly, Daily, and Monthly tabs.

To create a waterfall graph:

1. | Open a file containing results for a concentrating solar power (CSP) system.

2. | In the results area of the navigation menu, click Time Series Graphs. If necessary, click Run Analysis first.

3. | In the data viewer, click either the Hourly, Daily, or Monthly tab.

4. | Clear the TIME check box and any other check boxes that might be checked.

5. | Click the down arrow below the list of check boxes to scroll to the bottom of the list of variables.

6. | For parabolic trough systems, there are four groups of related variables that are suitable for waterfall graphs. Each of the four groups has a primary variable: Sol_Rad_Inc_on_Coll(Qdni), ThermalEnergy_Del_by_SF, ThermEnergytoPB, and EPGS_Losses. The first and second of these are followed by a series of "Less" variables, whose value is subtracted from its associated primary variable. For example, Less_SF_Inc_Ang_Losses is the Sol_Rad_Inc_on_Coll(Qdni) minus the solar field incident angle losses.

For dish-Stirling systems, there is one group of related variables suitable for a waterfall graph. The primary variable is Power_in_Receiver_Field, which is followed by a series of three variables whose names start with "Less" that can be used to construct the graph.

7. | Check the boxes for the variables that you want to appear in the waterfall graph. If you are on either the Hourly or Daily tab, zoom in or out to a suitable level of detail. (The zoom buttons are below the graph, to the right of the horizontal scroll bar.)

8. | Experiment with the graph by selecting and clearing check boxes.

Tip. You can change the properties of the graph by right-clicking the graph and selecting Properties in the pop-up menu.

Table 35. Waterfall variable names for parabolic trough systems in DView. Primary variables are shown in bold font.

Waterfall variable name | Description
--- | ---
Sol_Rad_Inc_on_Coll(Qdni) | solar radiation incident on collectors (Qdni)
Less_SF_Inc_Ang_Losses | minus Incidence angle for solar field (QSFnipCosTh)
Less_SF_Availability_Losses | minus solar field availability (QnipCosTh*SFAvail)
Less_SF_Opt_Eff_Losses | minus solar field optical efficiency (QSfAbs)
Less_Receiver_Thermal_Losses | minus receiver thermal losses (24hrs) (above - QsfHceHl)
Less_Piping_Thermal_Losses | minus piping thermal losses (24hrs) (above - QsfPipeHl)
Less_No_Operation(Low_Insol) | minus no op. low Insolation (Qsf - QhtfFpTES) Note: Qsf=Qcoll - Rec.HL - PipeHL
ThermalEnergy_Del_by_SF | thermal energy Delivered by solar field (QSF)
Less_TES_Full_Losses | minus TES full losses (above - QTSFULL)
Less_TES_Thermal_Losses | minus TES Thermal losses (above - QTSHL)
Less_Turbine_StartLess_Up_Losses | minus turbine start-Up (above - QturSU)
Less_Excess_above_PowBlck&TES | minus excess to power block / thermal energy storage
Less_Below_Turb_Min | minus the energy below turbine min (above Less_ Qmin)
ThermEnergytoPB-solar | thermenergy to power block from solar (Q_to_PB)
ThermEnergytoPB-fossil | thermenergy to the power block from fossil
ThermEnergytoPB-Total | thermal energy to the power block - total
EPGS_Losses | losses in conversion from thermal energy to electrical output from the power block
Gross_Electric_Generation | gross electric generation (E_gross)
Parasitic_OnLine_SelfGen | parasitics (on-line self generated)
Parasitic_OffLine_SelfGen | parasitic losses (off-line self generated)
Net_Electricity_Generated | net electricity produced (E_net)