In this document
We will introduce the Solargis Long-Term Averages (LTA) API, describing its main features and recommended use cases. It explains when to use LTA data and when to select higher fidelity datasets like TMY or Time Series for solar analysis.
Overview
Accurate and rapid estimation of solar energy potential is essential during the pre-feasibility phase of solar projects. The Solargis Long-Term Averages (LTA) API provides a robust solution, enabling swift prefeasibility photovoltaic (PV) yield calculations and delivering comprehensive long-term solar and meteorological data summaries—available as monthly and/or yearly aggregates—via a reliable API. Solargis LTA data is updated regularly, reflecting the most recent underlying satellite and model improvements.
Note: Solargis LTA API is offered as a single-plan subscription, and you can purchase it by contacting our sales team.
What is LTA?
Long-term averages (LTA) data represent multi-year, statistically averaged values of key solar and meteorological parameters (e.g., irradiation, temperature, wind). These monthly and annual means are computed over long periods—typically 15 to 30+ years—allowing you to quickly gauge the broad solar resource potential for any site, anywhere in the world.
Primary Use Cases
High-level pre-feasibility & screening: LTA data is ideal for early stage planning, mapping, site prospecting, and comparison of general solar potential over broad areas or many potential locations.
Portfolio analysis: Useful for development pipelines, national or regional policy planning, or when a fast, comparative assessment is needed.
Quick data integration: For software tools or dashboards that require rapid access to basic solar climate summaries, LTA is often the most practical data format.
What is LTA NOT suitable for?
LTA datasets do not capture interannual variability, seasonality, or extremes—they provide “climate normals” rather than real weather behavior.
Not for investment-grade yield analysis or bankable project simulations: LTA smooths out real-world variability, weather events, and rare occurrences (such as storms, heatwaves, or periods of unusual irradiance) that have major impacts on actual PV output and risk. For bankable simulations, use Time Series (TS) data (e.g., 15-minute, 5-minute, or 1-minute multi-year datasets)
Not for system design, detailed simulations, or due diligence: LTA data cannot inform calculations that require the realistic sequencing of sunny/overcast days, ramp rates, inverter clipping, curtailment, storage modeling, or regulatory compliance with grid standards. Use Time Series data for the most accurate system simulations, design optimization, and grid compliance assessments.
Not for risk assessment or insurance: LTA misses both year-to-year and intra-annual variability—an essential consideration for modern lenders, insurers, and plant operators.
Main features of the Solargis LTA API
Fast API integration: Immediate access to datasets through seamless API connectivity.
Quick PV potential assessment: Evaluate the photovoltaic potential of prospective sites within seconds using global PVOUT data.
Comprehensive global coverage: Access long-term average solar and meteorological data for locations worldwide.
Real-time data processing: Integrate and process API data directly in your prospection and planning software.
Custom application development: Build tailored applications and services for clients using robust, reliable datasets.
How to integrate
You can learn how to integrate and use the Solargis LTA API in the Solargis LTS API documentation.