Use the new weather data integration tools. Go to Resources → Solar → Global Solar Atlas to pull GHI, DNI, and DIF data for your latitude/longitude. For wind, use ERA5 reanalysis data.
For those new to the software or upgrading from an older version, here is a typical project workflow in version 3.15.
The most significant source of error in any HOMER model is rarely the solar irradiance data; it is the load profile. homer pro 3.15
In previous versions, users often defaulted to the synthetic load inputs (peak, average, randomness). In 3.15, the ability to import high-resolution data is seamless, yet many users ignore it.
The Deep Dive: A 10% error in your load prediction can result in a drastically different system architecture (e.g., adding a diesel generator where none is needed, or oversizing a battery bank). Use the new weather data integration tools
Goal: Reduce diesel consumption 70% with PV + storage
Click “Calculate.” HOMER 3.15 uses multi-threaded processing, which is significantly faster on modern CPUs compared to version 3.10. Results include: The Optimal System:
HOMER Pro 3.15 has introduced significant improvements in how it models battery degradation and kinetics. The old "Kinetic Battery Model" (KiBaM) is still there, but the software now allows for more nuanced definition of Lithium-Ion chemistries.
The Deep Dive: In legacy versions, batteries were often modeled with a fixed lifetime throughput (kWh throughput before failure). This is a linear approximation of a non-linear reality.
While HOMER Pro is updated regularly, version 3.15 includes several headlining features that differentiate it from earlier versions like 3.14 or 3.13.