The SENDER project is pleased to present a recent publication from our partner, CRS4, represented by Marino Marrocu and Luca Massidda. Their paper, titled “Estimating the Value of ECMWF EPS for Photovoltaic Power Forecasting”, has been published in the Solar Energy journal, Volume 279 (September 2024).

This important study explores innovative methods to improve forecasting for photovoltaic (PV) power generation, focusing on the value of using the European Centre for Medium-Range Weather Forecasts (ECMWF) Ensemble Prediction System (EPS). The research assesses the economic advantages of EPS-based probabilistic forecasting for solar energy, offering new insights that could significantly impact the renewable energy sector.

You can access it via: https://doi.org/10.1016/j.solener.2024.112801

In recent years, solar power has become one of the fastest-growing sources of renewable energy. As more photovoltaic (PV) plants are installed, it becomes crucial to predict how much power they will generate in the future. This is where forecasting comes into play. But traditional methods of prediction might not be enough anymore, especially when energy managers are trying to make the most out of their resources. A new study compares different forecasting approaches and introduces a groundbreaking way to assess their economic value, offering insights that could reshape how solar power predictions are made.

What is Forecasting in Solar Power?

At its core, forecasting for solar power (or PV power generation) involves predicting how much energy a solar panel or solar farm will produce. Traditional methods of forecasting often rely on weather data and other statistical models. However, as solar power becomes more integral to energy systems, there’s a growing need for more accurate and detailed predictions, especially when decisions can have significant financial impacts.

This study compares two different types of forecasting: deterministic-to-probabilistic (D2P) and probabilistic-to-probabilistic (P2P) approaches.

  • D2P forecasting takes a single, certain weather forecast and attempts to add layers of probability to predict energy output.
  • P2P forecasting, on the other hand, starts with multiple potential weather scenarios and derives a range of possible outcomes for PV production.

Both methods are valuable, but this study takes things further by introducing a new way to measure how useful these forecasts really are.

Going Beyond Traditional Metrics

Traditionally, forecasts are evaluated based on statistical accuracy—how close the prediction is to the actual outcome. But the study introduces a novel concept in PV forecasting: a metric that evaluates the economic value of these predictions.

This new metric doesn’t just focus on whether the forecast is right or wrong; it assesses how useful the forecast is for energy managers making real-world decisions. For example, knowing that a forecast could save money by allowing energy managers to make more informed decisions at various probability thresholds could be far more valuable than just having a statistically accurate prediction.

Real-World Data and a New Economic Perspective

The researchers based their study on actual production data from PV plants and used the European Centre for Medium-Range Weather Forecasts (ECMWF) to run their comparisons. Specifically, they looked at the ECMWF’s ensemble forecasting system (EPS), which provides a range of possible weather outcomes rather than a single prediction.

They found that when using EPS-based methods (P2P), the forecasts might not always look better at first glance—especially when using traditional accuracy metrics. However, by diving deeper and focusing on economic value, the advantages of using EPS become clear. Forecasts based on EPS were shown to provide significant benefits when considering the cost–loss ratios—essentially how much value an energy manager can gain depending on the probability of certain outcomes.

Why This Matters for the Energy Sector

The findings of this study have important implications for energy resource managers. One key takeaway is that even though an EPS-based forecast may require a larger upfront investment, its added economic value can make it more cost-effective in the long run compared to simpler, deterministic approaches.

This means that before adopting a forecasting system, energy managers can now use this innovative metric to perform a cost–benefit analysis. They can determine whether the additional complexity and cost of implementing an EPS-based forecast will ultimately lead to better financial outcomes for their solar energy projects.

By considering not just accuracy, but also the potential economic value of forecasts, this research offers a new way for the solar energy sector to make smarter, more informed decisions.

In a world where renewable energy is becoming increasingly important, innovative forecasting techniques like these could play a key role in ensuring solar power’s growth and efficiency.

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