Review of Different Error Metrics: A Case of Solar Forecasting

Abstract

Renewable energy systems (RES) are no longer
confined to being used as a stand-alone entity in the modern era.
These RES, especially solar panels are also used with the grid
power systems to supply electricity. However, precise forecasting
of solar irradiance is necessary to ensure that the grid operates in
a balanced and planned manner. Various solar forecasting
models (SFM) are presented in the literature to produce an
accurate solar forecast. Nevertheless, each model has gone
through the step of evaluation of its accuracy using some error
measures. Many error measures are discussed in the literature
for deterministic as well as probabilistic solar forecasting. But
each study has its own selected error measure which sometimes
landed on a wrong interpretation of results if not selected
appropriately. As a result, this paper offers a critical assessment
of several common error metrics with the goal of discussing
alternative error metrics and establishing a viable set of error
metrics for deterministic and probabilistic solar forecasting.
Based on highly cited research from the last three years (2021
2019), error measures for both types of forecasting are presented
with their basic functionalities, advantages & limitations which
equipped the reader to pick the required compatible metrics