Vaisala Energy Support
Why does the data not match my observations?
There are a number of reasons why values measured with ground-based instruments may not match our estimates. For example, your location may have highly reflective terrain making it difficult to distinguish from clouds in our satellite-derived values (please see “How accurate are the Solar Prospecting Tools?” for more details). Your location may also be affected by long-term climatic patterns, making your short-term observations indicate higher or lower irradiance values than our estimated average values, which take a longer period of time into consideration.
Unlike many competing products that are available, Vaisala has the ability to reprocess the satellite imagery used to create the data provided by the Solar Prospecting Tools for nearly any location worldwide. This allows Vaisala to customize and tune our processing algorithms to your solar observational data, nearly eliminating model bias, and providing a historical context for your data extending as far back as 22 years. The incorporation of your observational data results in superior accuracy and allows you to obtain a comprehensive understanding of your resource and the opportunities and risks related to solar energy development at your project location.
If you are interested in more detailed information on how Vaisala can incorporate your observational data into our modeled values, please contact us.
More Solar Online Tools 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?
- 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?
If you didn't find what you were looking for, please contact 3TIER Support for additional assistance.