Primary Uses
- Project feasibility
- Portfolio evaluation
- Site planning
- Validating observations with a historical perspective
Solar Site Resource Assessment offers the most accurate long-term estimates of solar resource intensity and variability by integrating on-site observations into the analysis.
As a leading innovator in atmospheric sciences, 3TIER offers custom reports for assessing large-scale solar projects anywhere in the world. Our analysis includes 13 to 15 years of statistically corrected, hourly time series data derived using state-of-the-art satellite modeling techniques and fine-tuned to the specific environmental context of your site with surface observations. Each report also provides a wealth of information on the key variables of GHI (Global Horizontal Irradiance), DNI (Direct Normal Irradiance), and DIF (Diffuse Horizontal Irradiance) and their long-term variability at your site.
By integrated on-site observations using advanced statistical techniques, 3TIER significantly reduces error and bias and offers the most accurate assessment of your project’s solar resources. In addition, we use a custom NWP model to deliver long-term, hourly wind and temperature data, which can have a substantial impact on power production. This depth of information enables you to perform detailed site design, long-term financial modeling, and seek critical funding for your project. Our reports also include uncertainty and probability analysis as well as the 1-year and 10-year exceedance values typically required by financing institutions.
As a single assessment provider with global capabilities, 3TIER allows you to make more informed decisions whether you are developing projects in California or Rajasthan. Our reports are based on a global, high-resolution solar irradiance dataset and uniform methodology, offering a consistent approach to solar assessment across the globe. Now you can make accurate site-to-site comparisons and gain a clearer picture of the risks and opportunities for every potential site in your portfolio.
| 3TIER Solar Time Series | Solar Site CVA | Solar Site Resource Assessment | |
| Product Features | |||
| Monthly variation of irradiance | X | ||
| Diurnal variation of irradiance | X | ||
| Annual mean maps of GHI, DNI, DIF | X | ||
| Irradiance histograms for GHI, DNI, DIF | X | ||
| Monthly variation of irradiance (with MOS correction) | X | ||
| Diurnal variation of irradiance (with MOS correction) | X | ||
| Irradiance histograms for GHI, DNI, DIF (with MOS correction) | X | ||
| Monthly temperature and wind speed variability (min, mean, max) | X | X | |
| Diurnal temperature and wind speed variability and 12x24 table of hourly means | X | X | |
| Time series for solar GHI, DNI, DIF | X | X | |
| Time series for solar GHI, DNI, DIF (with MOS correction) | X | ||
| Time series for 10 meter wind speed and 2 meter temperature (length dependent on region of purchase) | X | ||
| Time series for wind speed and temperature based on 4.5 km NWP model run | X | ||
| Uncertainty analysis | X | X | |
| Exceedance probability table | X | X | |
| Validation Report on the MOS-corrected irradiance time series compared to observations | X |
Portable Document File (PDF) report and data files in an easily integrated, comma-separated value (CSV) format.
Solar Site Resource Assessment utilizes 3TIER's satellite derived, high-resolution solar dataset along with on-site observations to deliver a MOS-corrected assessment of GHI (Global Horizontal Irradiance), DNI (Direct Normal Irradiance), and DIF (Diffuse Horizontal Irradiance) values at roughly a 3 km resolution. This process removes bias and adjusts the variance of the irradiance data to better match the provided observations.
Wind and temperature data are based on a customized 4.5 km NWP (Numerical Weather Prediction) model run for your particular site. 3TIER employs an NWP model called WRF (Weather Research and Forecasting). This model is widely supported and continually enhanced by the global atmospheric science and research community.
3TIER produced the first global solar irradiance map and time series dataset at roughly three times the resolution of previous US solar datasets and at thirty times the resolution of global datasets available from NASA. 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 actual, half-hourly, high-resolution 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. 3TIER 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.
| Regions | Satellites | Temporal Coverage |
| Western Hemisphere | GOES 8 - 13 |
15 years (January 1997 - present) |
| South Asia & Middle East | Meteosat 5, Meteosat 7 |
13 years (January 1999 – last quarter) |
| East Asia & Oceania | GMS 5, GOES 9, MTSAT 1-2 |
13 years (December 1998 – present) |
| Europe & Africa | Meteosat 7, Meteosat 9 |
15 years (July 1998 – last quarter) |
To develop and validate our model, 3TIER used observations from:
Find our validation papers here.
In order for us to process this report, you must provide the center latitude and longitude of your solar site and one year of high quality, solar irradiance observations taken within 2 km of the solar site.
If you are unfamiliar with the technical terminology on this page, please visit our Glossary for more information.
