Alliant Energy EPRI: Electric Power Research Institute
Madison Solar Demonstration Project
Madison Solar Demonstration Project

Site Settings

Slideshow Speed: Home Page and Image Gallery
Automatically advance to the next image:
Tip: pause a slideshow by clicking or advancing images manually.

Alternate Display Modes

Full Screen Mode
When using a desktop or laptop computer, you may be able to toggle full screen mode. Chrome, Firefox, and Internet Explorer: press [F11]. Edge: press [Shift]+[Windows key]+[Enter]. Safari: press [Control]+[Command]+[F]. Your browser may also have a menu option to enter full screen mode.
Billboard Mode
Entering this mode will automate the entire website, advancing through a predefined set of pages at specific time intervals. This mode is intended for kiosks or displays where user interaction is prohibited or not feasible. Do not use billboard mode with smartphones or tablets. Click here to enter billboard mode.

Contact Us

Contact Alliant Energy

For information about Alliant Energy or this project, call 1-800-ALLIANT (1-800-255-4268). Please contact EPRI for website support.

Contact EPRI

For website support or for information about EPRI or this project, call 1-650-855-2121, email askepri@epri.com or submit a form to contact EPRI's Customer Assistance Specialists.

About this website

This website was designed and developed by EPRI in collaboration with Alliant Energy, EPRI's Integration of Distributed Energy Resources and Solar programs, and EPRI's Power Delivery and Generation sectors.

Help: information about this page...

Component View

After reading the overview, try interacting with the comparison chart(s) to learn more about the data's characteristics and trends.

Panels

This page contains several panels: Performance Snapshot, Overview, etc. Tap or click the "?" button in the upper right corner of a panel to see more information about its content.

  1. Site Overview
  2. Weather
  3. Precip (Outdoor Conditions)

Precipitation

Performance Snapshot
Performance Snapshot

This panel may show a sampled measurement (e.g., power) and/or a cumulative measurement (e.g., energy generated).

When the sampled measurement is available, a gauge and trend chart will appear.

When the cumulative measurement is available, its value will be shown over the date range indicated.

Sampled Value (Gauge and Chart)

Precipitation rate (rainfall and/or snowmelt)

Cumulative Value

Cumulative rainfall or snowmelt

Precipitation Rate
Precipitation
---
in
Precipitation Rate (in/h)
Overview
Enlarge Image

Precipitation levels can have either a positive or negative effect on PV power output, depending on the type of precipitation. For example, studies have shown that PV systems affected by soiling typically increase their power output after a rainfall, as the rain washes debris from the solar modules. This is why PV systems in regions with regular rainfall are typically less affected by soiling losses than are those in arid regions. In contrast to rain precipitation, snow has a negative effect on power output, as its accumulation blocks the solar arrays from receiving sunlight until the snow melts.

Measurement Source

Precipitation levels are measured using a tipping-bucket rain gauge. The 8-inch diameter tipping-bucket measures cumulative rainfall. It also collects and melts frozen precipitation (snow or ice) then measures the amount of water - a technique that is not precise.

Time Series Profile
Time Series Profile

Chart (or charts) shows trends for a specific component. Each data point represents an aggregated value for the time interval indicated (e.g., 15-minute average).

Chart Navigation

Tap or click on the chart titles (if more than one shown) to switch the view between charts. The title of the displayed chart is highlighted in orange.

Zoom and Pan

To zoom in on and get a closer view of a plot area in a chart:

  • On a touchscreen: Use two fingers to spread apart (expand) the plot area, then use one finger to slide the plot area left and right.
  • Using a mouse: Click and drag to select a section of the plot area, then hold down the Shift key while dragging left and right.
  • Tap or click on the "Reset zoom" button to return the chart to its original size.

Toggle Legend Items

Tap or click on a legend item (if more than one shown) to hide or show its data in the plot area.

Measurements Plotted

Chart (or charts) includes one or more of the following measurements (indicated in the legend or title):

  • Precipitation rate (rainfall and/or snowmelt)

Preset Date Ranges

Custom Date Range

to
Data are available from 4/1/2016 through 7/26/2020. Clear the end date to view the most recent data available.
Tip: click "?" (next to the Edit button) to learn how to interact with the chart.

Download Chart Data

Save chart data as a comma-separated values (CSV) file:
Note: timestamps (first column in the CSV file) are adjusted to your computer's time zone and represent the beginning of each interval.
Warning: downloading data is intended for desktop and laptop computers. This feature may not work for smartphones or tablets.
PRECIPITATION RATE
Daily Performance
Daily Performance

Chart (or charts) shows trends for a specific component. Each data point represents an aggregated value for the date indicated.

Chart Navigation

Tap or click on the chart titles (if more than one shown) to switch the view between charts. The title of the displayed chart is highlighted in orange.

Zoom and Pan

To zoom in on and get a closer view of a plot area in a chart:

  • On a touchscreen: Use two fingers to spread apart (expand) the plot area, then use one finger to slide the plot area left and right.
  • Using a mouse: Click and drag to select a section of the plot area, then hold down the Shift key while dragging left and right.
  • Tap or click on the "Reset zoom" button to return the chart to its original size.

Toggle Legend Items

Tap or click on a legend item (if more than one shown) to hide or show its data in the plot area.

Measurements Plotted

Chart (or charts) includes one or more of the following measurements (indicated in the legend or title):

  • Cumulative rainfall or snowmelt

Preset Date Ranges

Custom Date Range

to
Data are available from 4/1/2016 through 7/26/2020. Clear the end date to view the most recent data available.
Tip: click "?" (next to the Edit button) to learn how to interact with the chart.

Download Chart Data

Save chart data as a comma-separated values (CSV) file:
Note: dates (first column in the CSV file) are based on the site's geographic location, which may be different from your computer's time zone.
Warning: downloading data is intended for desktop and laptop computers. This feature may not work for smartphones or tablets.
CUMULATIVE PRECIPITATION
Monthly Performance
Monthly Performance

Chart (or charts) shows trends for a specific component. Each data point represents an aggregated value for the month indicated.

Chart Navigation

Tap or click on the chart titles (if more than one shown) to switch the view between charts. The title of the displayed chart is highlighted in orange.

Zoom and Pan

To zoom in on and get a closer view of a plot area in a chart:

  • On a touchscreen: Use two fingers to spread apart (expand) the plot area, then use one finger to slide the plot area left and right.
  • Using a mouse: Click and drag to select a section of the plot area, then hold down the Shift key while dragging left and right.
  • Tap or click on the "Reset zoom" button to return the chart to its original size.

Toggle Legend Items

Tap or click on a legend item (if more than one shown) to hide or show its data in the plot area.

Measurements Plotted

Chart (or charts) includes one or more of the following measurements (indicated in the legend or title):

  • Cumulative rainfall or snowmelt

Preset Date Ranges

Custom Date Range

to
Data are available from 4/1/2016 through 7/26/2020. Clear the end date to view the most recent data available.
Tip: click "?" (next to the Edit button) to learn how to interact with the chart.

Download Chart Data

Save chart data as a comma-separated values (CSV) file:
Note: dates (first column in the CSV file) are based on the site's geographic location, which may be different from your computer's time zone.
Warning: downloading data is intended for desktop and laptop computers. This feature may not work for smartphones or tablets.
CUMULATIVE PRECIPITATION
Cumulative Performance
Cumulative Performance

Chart (or charts) shows aggregated values for the date range indicated.

Chart Navigation

Tap or click on the chart titles (if more than one shown) to switch the view between charts. The title of the displayed chart is highlighted in orange.

Zoom and Pan

To zoom in on and get a closer view of a plot area in a chart:

  • On a touchscreen: Use two fingers to spread apart (expand) the plot area, then use one finger to slide the plot area left and right.
  • Using a mouse: Click and drag to select a section of the plot area, then hold down the Shift key while dragging left and right.
  • Tap or click on the "Reset zoom" button to return the chart to its original size.

Toggle Legend Items

Tap or click on a legend item (if more than one shown) to hide or show its data in the plot area.

Measurements Plotted

Chart (or charts) includes one or more of the following measurements (indicated in the legend or title):

  • Cumulative rainfall or snowmelt

Preset Date Ranges

Custom Date Range

to
Data are available from 4/1/2016 through 7/26/2020. Clear the end date to view the most recent data available.
Tip: click "?" (next to the Edit button) to learn how to interact with the chart.

Download Chart Data

Save chart data as a comma-separated values (CSV) file:
Note: timestamps (first column in the CSV file) are adjusted to your computer's time zone and represent the beginning of each interval.
Warning: downloading data is intended for desktop and laptop computers. This feature may not work for smartphones or tablets.
CUMULATIVE PRECIPITATION
Image for Precipitation