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How SolarAnywhere Data compares with other data sources

Is the Perez model used to generate SolarAnywhere Data new or different from the one used by the NREL NSRDB?

SolarAnywhere Data is generated using a more recent version of the Perez model than that used to generate the NSRDB 2005 and 2010 updated datasets. SolarAnywhere also provides more recent data through the last hour, forecasts and other features that are not available from the NSRDB.

How does SolarAnywhere Data compare with NREL TMY data?

Typical Meteorological Year irradiance data available from NREL is synthesized from historical sources to represent a “typical” year for a fixed number of sites in the U.S. SolarAnywhere represents actual hourly estimates of irradiance for each specific location based on satellite imagery and atmospheric conditions at the site. Visit Typical Year Files for more detail.

Learn more in this paper, “How Misuse of Solar Resource Datasets Is Reducing Solar Industry Profits.

How do satellite-derived irradiation sources compare with output from ground-based measurement instruments?

If properly calibrated and maintained, ground-based instruments can be very accurate for the immediate area around the equipment. As the area of interest is located further from the unit, the accuracy declines, increasing the usefulness of satellite-based observations. The cost of equipment, inaccuracies from calibration and long setup times can favor satellite over ground-based measurements. Satellite irradiance is also often used in conjunction with ground-based instruments, and is particularly useful for detecting ground device calibration drift and for filling in missing data.


SolarAnywhere Methodology

What data sources are used when generating SolarAnywhere Data?

Cloud, albedo, elevation, temperature and wind speed data are used in conjunction with satellite imagery collected from geosynchronous satellite networks. Visit Historical Model for more detail.

How often is new SolarAnywhere Data made available?

SolarAnywhere real-time data is collected, processed and available for use within approximately one hour. When the forecast option is licensed, a continuous dataset extending from January 1, 1998 through the present, and up to 168 hours into the future is available.

Why are different models used when forecasting days-ahead and hours-ahead data periods?

Short-term SolarAnywhere forecasts utilize a vector-based cloud model. Longer-term forecasts rely on numerical analysis. The bifurcated approach utilizes the method expected to give the best results for the time interval requested. Visit the Forecast page for more detail.

What happens when the SolarAnywhere model changes?

SolarAnywhere modeling algorithms and input data sources are occasionally updated to improve accuracy, consistency and availability. Updates to the modeling algorithms are released as new SolarAnywhere versions. Within each new data version, historical data is reprocessed using the updated algorithm to take advantage of the improved accuracy. Data versioning is a key factor of solar resource data bankability as it allows investors, independent engineers, etc., to reproduce results. See the release notes for a summary of model improvements.

To provide continuity for users of older SolarAnywhere datasets, and allow comparisons between data versions, prior versions are also available. Support back to SolarAnywhere version 3.2 is available via data.solaranywhere.comContact us for information on prior datasets.

There are periods of missing measurements in my SolarAnywhere file. Why?

Missing data occur in the SolarAnywhere irradiance database due to missing satellite images. Missing images are normal and occur due to rare unplanned outages and regular maintenance performed by the National Oceanic and Atmospheric Administration (NOAA). Missing data also occur in the ancillary surface air temperature and wind speed data due to periods of missing measurement from ground-based sensor networks.

Visit the Missing Data page to learn more about how SolarAnywhere handles missing data.

What is the difference between TGY and P50 data?

We’re sometimes asked whether a TGY is a P50. In short, no. The typical year is constructed of closest-to-average months. In practice, the annual total of a typical year is very similar to the average of the annual totals of the timeseries. P50, on the other hand, represents the median year of the distribution. Half of future years are expected to fall above the value, and half are expected to fall below.

TGY and P50 are often similar but diverge for asymmetrical distributions. Visit Probability of Exceedance to learn more about SolarAnywhere PXX Data.

SolarAnywhere Licensing Options

How are geographic areas defined when licensing data?

The basic geographic unit is a satellite visible “tile.” Tile areas directly correspond to satellite image resolution. SolarAnywhere offers data in 10 km nominal (0.1 x 0.1 degree) resolution in all available regions, and up 1 km nominal (0.01 x 0.01 degree) resolution in select regions. For information on licensing, see purchase options or contact us.

What if I need more Typical Year sites in a year than my license allows?

You can upgrade to the unlimited license, purchase a fresh Professional license valid for 1 year or purchase single TGY credits. You can see all the licensing options here.

These purchases can be made online with a credit card by logging into SolarAnywhere and visiting the Purchase page, or by contacting us to receive an invoice.

What if I need more Sites in a year than my license allows?

You can purchase single Sites credits online with a credit card by logging into SolarAnywhere and visiting the Purchase page, or by contacting us to receive and invoice. You can also upgrade to a 10 or 50 pack of sites for a per-site pricing discount. If you anticipate needing more than 8 sites, it then makes sense to purchase a 10-pack of sites based on our Sites pricing structure. You can see all the licensing options here.





Can I access SolarAnywhere Data to support my research free-of-charge?

Yes, students, researchers and the solar industry have no-cost access to complete and current SolarAnywhere Typical Year and Time-series data at select locations around the world with a Public license. These data can be used for educational purposes, and to research new and improved solar PV models for risk assessment, operations and maintenance, intelligent energy dispatch and more.

For a limited time, data that was formerly available via NREL and CPR/SUNY’s Solar Prospector tool is available with a SolarAnywhere Academic license. This legacy dataset was generated using older SolarAnywhere data versions and is only available for locations in the U.S.

Commercial use of SolarAnywhere data obtained through a Public or Academic license is not supported. You can see all the licensing options here.