Why Use Improved Generation Forecasting?

Grid operators have forecasted load for decades and know how much load there will be, often with remarkable certainty, for a given range of weather conditions at any given time. Forecasting generator availability and output—especially for variable wind and solar plants that make up a growing share of output in many countries—is a much newer process. Implementing or improving generation forecasting can play an important role in operating a power system efficiently and reliably.

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Main Points

• Energy forecasting refers to using weather data with greater accuracy over shorter time scales for more locations to enable better estimates of wind and solar output.
• The output estimates are obtained by using the weather data as an input into models of wind and solar generator performance.
• Having estimates of how much wind and solar generation is likely to be available in the intraday and day-ahead dispatch cycle can allow grid operators and utilities to minimize the need for both spinning and standby reserves, and make more efficient use of the available transmission system.
• Implementing or improving existing energy forecasting can also help in the overall long-term power planning process.

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First, See This Figure

VRE forecasting is the process of converting weather forecast data into a prediction of the power generated by the available capacity of a VRE power plant.

Fig. 4 from p. 8 of Scaling Up Renewable Energy Project Grid Integration Series: Variable Renewable Energy Forecasting by USAID.

Next, Read This Overview

Now, Read This Summary of Benefits

Next, See This

The table below quantifies the fuel savings from improved energy forecasting in a power system, depending on the level of forecast improvement and different levels of solar penetration.

See: Excerpt from page 11 of Advanced Forecasting of Variable Renewable Power Generation by IRENA.

Finally, See This

This table quantifies the cost savings of improved energy forecasting for the same power system as above, again depending on the level of forecast improvement and different levels of solar penetration.

See: Excerpt from page 12 of Advanced Forecasting of Variable Renewable Power Generation by IRENA.

Suggested Actions & Next Steps

• Discuss existing generation forecasting processes for your power system with relevant stakeholders (e.g., grid system operators).
• Assess current forecasting practices and their performance (i.e., forecast errors).
• Consider which stakeholders would need to be included in a formal process for implementing improved forecasting system.