In this article:
- CSV Overview
- Sample Excel Models
- International CSV Exports (Comma vs. Decimal Points)
- CSV Column Explanations
CSV Overview
HelioScope models the performance of the array for every hour of the year. When you run a simulation and open the Production Report, it will provide a summary of that data. If you want to view the hourly data that underpins the report click the gray CSV button next to the PDF button (highlighted below):
The CSV file will contain 8760 rows, one for every hour of the year. Each column represents one of the steps in the HelioScope simulation starting with the weather file data and running through each of the losses that occur in the system. If you just want to analyze the actual production of the array you'll want the last column "grid_power". Having trouble finding column labels? Just select the first row in excel and enable text wrapping to see the full title for each column.
Sample Excel Models
The 8760 CSV file is always in the same format so you can build Excel models that reference a second tab and just drop the CSV into the model. The HelioScope team has developed a few Excel models to get you started that are linked below:
- 12 x 24 spreadsheet: converts the 8760 into a monthly x hourly table so you can quickly assess when the array produces energy throughout the year.
- Comparison Spreadhseet: allows you to compare two CSV files side by side. Easily identify why one design produces more than another.
- Monthly losses: Monthly the production report summarizes the losses for the entire year. This spreadsheet breaks out each loss by month allowing you to see when the losses occur throughout the year.
- Max Day Curve: shows the production curve for the highest producing day of the year.
- 8760 with Zeros: adds a zero to empty values for easier copying & pasting.
- AC Power Limit: Recalculates ac_power and grid_power assuming a fixed maximum AC output. Can be used for modeling power factor derates by setting a proportional AC power limit.
International CSV Exports (Commas vs. Decimal Points)
Europe and America use periods and commas differently when separating between decimal points and thousands.
- American: 0.50% 150,000
- European: 0,50% 150.000
HelioScope uses the American formatting for decimal points. This can cause issues when importing HelioScope CSV files internationally if your text to column settings interpret the decimal point as a thousand separator. More information on how to update the CSV file to the European format here
CSV Column Explanations:
Quick note: everything after column Y in the CSV is in watts. Each row represents an hour so the units are equivalent to watt hours. The data is in hour-beginning format, so the hour 1/1/YY 0:00 represents midnight to 1:00am.
Column Name | Description | Units |
Weather Values | ||
hour_index | The hour of the year. Between 1 and 8760 | Integers |
timestamp | Date and time of the simulation | MM/DD/YYYY |
global_horizontal_irradiance | the total amount of sunlight available at a given moment, based on a collector that is oriented perfectly flat on the ground. This includes both the direct and diffuse components of the sunlight. | W/m^{2} |
direct_normal_irradiance | Direct Normal Irradiance (DNI) is the amount of solar radiation received per unit area by a surface that is always held perpendicular (or normal) to the rays that come in a straight line from the direction of the sun at its current position in the sky. | W/m^{2} |
diffuse_horizontal_irradiance | The indirect sunlight that is available to a collector that is oriented flat on the ground. This includes the general brightness of the sky, as well as reflected light. The best way to visualize this irradiance is to picture a person’s shadow on a sunny day. The ground under the shadow is not totally dark, even though the direct component has been removed. The remaining sunlight is the diffuse irradiance. | W/m^{2} |
dry_bulb_temperature | The air temperature at a given point in time. Note that this is not the same as the cell, temperature – that is calculated separately based on a few inputs. | ºC |
windspeed | The speed of the wind. This is used in the cell temperature calculations. | m/s |
albedo | Reflected irradiance represents sunlight that is reflected off the ground around an array. It is calculated based on an albedo coefficient (which is the portion of the incident irradiance that is reflected), and the share of the ground that is visible from the module. The albedo coefficient is typically 0.2, though it can be higher during snowy periods in cold climates. | |
Irradiance Values | ||
solar_altitude_angle | Solar Altitude Angle | Degrees |
solar_azimuth_angle | Solar Azimith Angle (0º is true North) | Degrees |
solar_incident_angle | Average solar incident angle relative to module orientation (0º is normal to module orientation) | Degrees |
horizon_elevation_angle | Elevation of horizon at solar azimuth angle (derived from Horizon file; if there is no Horizon file in the Condition Set, this will be 0) | Degrees |
adjusted_ghi | GHI value after accounting for spectral analysis(if using thin film modeling). | W/m^{2} |
poa_direct_irradiance | Average Direct (Beam) Irradiance Incident on the Plane of Array of the Modules | W/m^{2} |
poa_diffuse_irradiance | Average Diffuse Irradiance Incident on the Plane of Array of the Modules | W/m^{2} |
poa_reflected_irradiance | Average Reflected (Albedo) Irradiance Incident on the Plane of Array of the Modules | W/m^{2} |
shaded_direct_irradiance | Average Direct (Beam) Irradiance Incident on the Plane of Array after Shading effects | W/m^{2} |
shaded_diffuse_irradiance | Average Diffuse Irradiance Incident on the Plane of Array of the Modules after Shading effects | W/m^{2} |
shaded_reflected_irradiance | Average Reflected (Albedo) Irradiance Incident on the Plane of Array of the Modules after Shading effects | W/m^{2} |
effective_direct_irradiance | Average Direct (Beam) Irradiance Incident on the Plane of Array after Shading and IAM effects of the Modules | W/m^{2} |
effective_diffuse_irradiance | Average Diffuse Irradiance Incident on the Plane of Array of the Modules after Shading and IAM effects | W/m^{2} |
effective_reflected_irradiance | Average Reflected (Albedo) Irradiance Incident on the Plane of Array of the Modules after Shading and IAM effects | W/m^{2} |
soiled_irradiance | Average Irradiance available to Modules after all effects and soiling factor | W/m^{2} |
total_irradiance | Average Irradiance available to Modules after all effects, soiling factor, and any defined irradiance variation | W/m^{2} |
Power Values | ||
nameplate_power | Total nameplate power of system, Irradiance * Module Nameplate | W |
avg_cell_temp | Average Module Cell Temperature | ºC |
module_irradiance_derated_power | Total Module Power after derating for Irradiance | W |
module_mpp_power | Total Module Power after derating for Irradiance and Temperature | W |
module_power | Total Module Power under array operating conditions, e.g. including any losses due to mismatch or operation away from module MPP | W |
optimizer_input_power | Total power input into power optimizers in the array | W |
optimizer_output_power | Total power output from power optimizers in the array, ie including optimizer operational efficiency | W |
optimal_dc_power | Total DC power of the array, including DC wire losses | W |
optimal_dc_voltage | Optimal system voltage unconstrained by inverter voltage range | V |
inverter_overpower_loss | Power loss due to constraining power down to inverter max power rating | W |
inverter_underpower_loss | Power loss due to insufficient power for inverter minimum power rating | W |
inverter_overvoltage_loss | Power loss due to constraining voltage down to inverter max voltage rating | W |
inverter_undervoltage_loss | Power loss due to insufficient voltage for inverter minimum voltage rating | W |
actual_dc_power | Total DC system power after accounting for inverter operating range | W |
actual_dc_voltage | Operating system voltage after accounting for inverter operating range | V |
ac_power | Total AC System Power, after accounting for inverter efficiency, excluding AC transmission losses to interconnect | W |
grid_power | Total AC System Power, including AC transmission losses to interconnect | W |