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Online Solar Resource Tools


    Solar Time Series Tools

     Solar Time Series Tools

    Vaisala has made it easier than ever to access high-quality global solar data for resource assessment.

    The Solar Time Series provides access to five global datasets, updated monthly, for one low annual price. Use our online Solar Time Series Tools to quickly visualize and order time series.

    • Minimize development risk - Rapidly compare weather resource data from multiple high-quality datasets to hedge against later resource answer changes by understanding the spread of answers up front
    • Improve energy estimates - Reducing the cost of solar resource data allows better-quality energy estimates to be prepared earlier in the development process
    • Data When You Need It - Moving at the speed of solar development long-term time series and TMY data are delivered to you in less than 24 hours so you can meet your tight deadlines
    • Fast Subscription Access - Access to hundreds of data files with all the weather variables you need for a single annual fee means never settling for low quality data. Get instant access! Click for more information or to purchase online.
    Solar Prospecting Tools

     Solar Prospecting Tools

    Gain quick and easy access to critical information using our Solar Prospecting Tools. This product enables developers, manufacturers, and installers to quickly explore solar potential worldwide with a user-friendly point and click interface. Now you can make more informed early-stage decisions before visiting sites or collecting observational data.

    • Unlimited Access
      With the click of your mouse you have access to solar irradiance data at any location across the globe. And you can share resource maps and data with colleagues and clients by printing professional reports directly from your browser.
    • Solar Variability
      View both annual and monthly mean values of GHI (Global Horizontal Irradiance), DNI (Direct Normal Irradiance), and DIF (Diffuse Horizontal Irradiance) from a 3 km resolution dataset based on over a decade of satellite data.
    • Access to 3TIER Dashboard tools
      Tailor the way you see information to the specific needs and demands of your work all within a seamless, drag and drop interface featuring customizable page layout options, scalable graphics, and multiple page views.
    Solar API Data Feeds

     Solar API Data Feeds

    Vaisala's solar and wind datasets provide in-depth resource data for any location worldwide. Our online maps and data products are the 'go-to' tools for utility-scale developers needing to quickly vet potential project locations. Our long-term average and time series datasets as well as the maps are available through APIs and can be used for internal tools or an external webpage for your clients.

    Solar Resource API (Application Programming Interface) enables you to integrate our scientifically derived, third party resource data into your own internal applications and customer experiences. You can use the API to build revenue-generating applications and mash-ups including:

    • Web-based lead generation programs
    • Internal and customer-facing sales tools
    • Product selection tools
    • Project design and financial modeling tools

    Our Solar Resource API's access Vaisala's data using simple REST calls. It is an open, standards based, XML programming interface. To make integration simple and quick, Vaisala provides detailed developer documentation, programming examples, and sample code.

    Technical Overview

     Technical Overview

    Product Highlights

    • Global coverage
    • Spatial resolution of 2 arc minutes (approximately 3km)
    • Based on over a decade of satellite data with continual updates
    • Validated and developed using widely recognized datasets worldwide
    • Online delivery for web tools
    • REST API delivery for data feeds


    Vaisala produced the first high-resolution global solar irradiance map and time series dataset at roughly Based on over a decade of satellite imagery and cutting-edge technology, our uniform methodology is supported by a large scientific and research community and results in a consistent map and dataset, enabling more accurate point-to-point comparisons.

    The dataset is based on visible satellite imagery observations via the broadband visible wavelength channel at a 2 arc minute resolution. These data have been processed to hourly GHI, DNI, and DIF values. Vaisala processes the satellite images based on a combination of in-house research and algorithms published in peer- reviewed scientific literature. These algorithms contain parameters and coefficients that are based on empirical fits to observational data. The specific satellites and length of time varies slightly by region due to differences in the availability of data from region to region. See the chart below for more details.

    RegionsSatellitesTemporal Coverage
    Western HemisphereGOES 8 - 14January 1997 – last month
    South Asia & Middle East          Meteosat 5, Meteosat 7January 1999 – last month
    East Asia & OceaniaGMS 5, GOES 9, MTSAT 1-2, Himari-8          December 1998 – last month          
    Europe & AfricaMeteosat 7, Meteosat 9-10July 1998 – last month

    To validate our model, Vaisala used independent observations from:

    • SurfRad
    • Baseline Surface Radiation Networks
    • National Solar Radiation Database
    • Bureau of Meteorology (Australia)
    • National Institute of Water and Atmospheric Research (New Zealand)
    • Indian Meteorology Department
    • NREL Annex II

    Find our validation paper here.