
As renewable penetration rises and forecasting grows more complex, traditional accuracy metrics often fall short. This white paper introduces a clearer, more reliable framework for evaluating forecast performance giving energy professionals a stronger foundation for comparing assets, assessing model quality, and improving decision-making.

With increasing number of solar photovoltaic power plants coming online, solar forecasting is becoming more important for many players within the power and utility industry. With these growing use cases, it’s just as important to understand how accurate your forecasts are. However, any forecast is going to have a margin of predictive error.
The utility industry has several conventional metrics for assessing predictive error in load forecasting. But none of them are the right fit for the unique characteristics of solar and solar forecasting.
In this paper, we examine: