Solar Online Tools

The Solar Online Tools are a powerful, web-based application with a simple point and click map for easily accessing renewable resource data. For help using these tools, please select from the below list of frequently asked questions. If you require additional assistance, please contact 3TIER Support.

Processing of the Vaisala solar data is delayed approximately 3 to 4 weeks behind realtime as we wait upon MERRA2 aerosol data for the version 2.1 dataset.

Currently, time series data for all regions are available through the end of February 2025.

Frequently Asked Questions

• How accurate is the data in the Solar Time Series Tools?
• The datasets give different answers. Which one is right?
• Why are there so many (5) different versions of solar data?
• Which weather data source should I pick?
• Why do the values in my TMY file change?
• What updates were applied to the datasets in November 2019?
• What's the latest month available in the solar time series tool?
• What solar values are shown on the map in solar prospecting and solar time series tool?
• How do I enter a location?
• Why does the map disappear?
• How do I interpret the graphs provided by the Monthly Mean Irradiance Tools in the Prospecting Tools?
• What do the Annual Mean Irradiance Tools in the Prospecting Tools provide?
• How can I compare sites side-by-side in the Prospecting Tools?
• How much area is covered by the Solar Prospecting Tools?
• How accurate are the Solar Prospecting Tools?
• What data is shown in the Solar Time Series Viewer?
• What data can I get from the Solar Time Series Download tool?
• What is the Vaisala 1.0 dataset?
• What is the Vaisala 1.1 dataset?
• What is the Vaisala 1.2 dataset?
• What is the Vaisala 2.0 dataset?
• What is the Vaisala 2.1 dataset?
• What are the units of irradiance?
• What is the “TMY” Data Type in the Solar Time Series Download tool?
• What is the “Long-Term” Data Type in the Solar Time Series Download tool?
• Why does the data not match my observations?
• How do I input CSV files into PVSyst?
• How can I input time series data into PVSyst?
• What is Global Horizontal Irradiance?
• What is Direct Normal Irradiance?
• What is Diffuse Horizontal Irradiance?
• What affects solar radiation at a given site?