Documentation

No matter the order option you prefer, you will need to make some choices regarding the type of dataset included in the order:

• Type of dataset: Time Series or TMY?
• Parameters package: Basic or Professional?
• Time integration: Hourly or Sub-hourly?
• Period: Full-time series or Specific period?
• Add GTI configuration (optional) 
• Add a project site name (optional)

In the next articles, we will go through some tips on how to make your data choices.

To finally send your data orders, you can follow these instructions if you have a contract/pre-paid subscription, or these instructions for making a one-time purchase.

The Full Time Series is the original data product generated by Solargis model, the one which contains the data values for the whole registered period. Since the information contained by a Time Series file is not compressed, it is the most versatile file able to provide inputs for all the calculations needed to run a complete solar resource assessment.

Solargis multi-year time series is most typically used for the following purposes:

• To understand seasonal and inter-annual variability of solar resource
• To understand occurrence of extreme irradiance and temperature events - for design optimization of solar power systems
• Input data for energy simulation of solar power systems
• For accuracy enhancement of long-term satellite-derived irradiance estimates - when high-quality irradiation measurements are available at project site

The Typical Meteorological Year (TMY) is a popular data product designed for summarizing the average weather conditions of a specific site in a period of a single year. TMY data is primarily used for energy simulation purposes, as popular simulation software such as PVsyst, SAM, etc. typically work with 8760 hourly values representing a typical year. The main reason for the popularity of TMY dataset for solar energy simulation is compatibility of such data with popular energy simulation software and speed of simulation.

The TMY is indeed constructed from Time Series (more info about TMY methodology here), so it is usual to find both data files within the same order files in Solargis. However, since TMY data results in an avoidable loss of information, it is recommended to use a full time series file when possible. 

When generating TMY data, we try to select months in such a way that annual sum of GHI/DNI values in the TMY file is consistent with the annual average calculated from time series. However, it may not be possible to find representative months where the sum of irradiation as well as meteo values will equal the long-term average. Therefore, we may be required to slightly adjust the meteo values to maintain similar averages as calculated from time series.

To download sample Time Series or TMY you can click here.

After calculating model statistics by comparing Solargis model with good quality ground measurements in more than 230 sites across all type of climates, here is a summary of the accuracy of solar radiation data from Solargis:

Usually the needs of each project are different. Thus the required parameters depend on the scope of the assessment, as well as the identified challenges expected for the geography at a particular site. In our pricing page you can check the subscription plans we have (Basic, Professional, etc) and their differences in terms of included data parameters.

In the table below we have listed the most relevant parameters required for assessing particular aspects of the expected energy output:

List of acronyms and parameters:

• GHI Global horizontal irradiance
• DIF Diffuse horizontal irradiance
• DNI Direct normal irradiance
• TEMP Air temperature at 2 metres (dry bulb)
• WS Wind speed at 10 metres
• WD Wind direction at 10 metres
• WG Wind gust
• PWAT Precipitable Water
• RH Relative humidity
• AP Atmospheric pressure
• SDWE Snow depth water equivalent
• SFWE Snow fall water equivalent
• PREC Precipitation
• ALB Ground albedo
• HOR Horizon profile

The calculation of Global Tilted Irradiance (GTI), also known as the total incident energy on the Plane of Array (POA), is a key step when doing a solar resource assessment. The ‘transposition model’  makes use of the geometric relationship that exists between the main solar irradiance components available (global, diffuse and direct) at every instant, taking into account the changing sun elevation and azimuth angles at every instant for a particular system configuration.

When sending orders, there is the possibility (optional) of including this calculation. The values will be represented as another column in the data files and will be calculated using high resolution data and reliable transposition models from Solargis.

The table below shows the configuration inputs needed for the most common types of solar power systems:

*Relative spacing is calculated by dividing the distance between two axis or pitch (P) and the trackers length (L). See calculation of relative row spacing value in the image (= x3/x2). 

Yes, it is possible to name your project site on solargis.info. After you enter your coordinates or select it on the map, on the left hand side you can click “Add site name” under “Selected site”.