a forecasting tool for Novar

The SDE adjustment amount revealed earlier

Projects Forecast Tool for the SDE Adjustment Amount

The financial returns from solar farms depend in part on figures that are not known until after the fact. This makes it difficult to plan ahead, especially when project developers want to prepare their financial plans and reports early in the year. With a forecasting tool developed byRepowered, Novar can gain earlier insight into a key component of those returns:the SDE++ adjustment amount.

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An important factor that has yet to be disclosed is

Novar has been developing and operating solar energy projects both domestically and abroad for more than ten years. Early insight is crucial for accurately estimating the expected performance and revenue of these projects.

The adjustment amount is a key factor in this regard. It provides an indication of the market value of electricity and is used to calculate the SDE++ subsidy per megawatt-hour (MWh) produced. If the market value of electricity rises, the SDE++ subsidy decreases. If the market value falls, the subsidy increases. In this way, the subsidy fluctuates in line with the market.

The Netherlands Environmental Assessment Agency (PBL) determines the adjustment amount retrospectively using a fixed method, based on the previous year’s market results. As a result, part of the expected revenue does not become clear until later.

An early forecast based on operational data

Repowered developed aforecasting tool toreliably estimate theSDE++ adjustment amountearly in the year.

This forecast is made possible by the extensive dataset of operational data from solar farms that Repowered has at its disposal. This real-world data forms the basis for estimating market outcomes: both the expected revenues on the day-ahead market and the operational costs resulting from imbalance. This estimate is then combined with the PBL’s published calculation method.

This results in a well-founded and accurate forecast before the official adjustment amount is known.

The graph shows the SDE adjustment amount for Repowered’s portfolio in **three scenarios**: without excluding periods with negative prices, excluding periods of six or more consecutive hours with negative prices, and excluding every 15-minute interval (ISP) with a negative price. For each date, the amount is calculated based on the preceding twelve months: the oldest day is excluded from the calculation, and the most recent day is included. The calculation is updated daily. A forecast is included for future dates. The more periods with negative prices that are excluded, the higher the calculated adjustment amount.

Earlier insight, better financial planning

Using this tool, Novar can estimate the adjustment amount early in the year and, consequently, the expected SDE++ subsidy per MWh generated. This provides greater certainty when forecasting solar farm revenues and when preparing financial plans and reports.

Olaf Neuteboom, Director of Renewable Assets at Novar

“Accurately forecasting the adjustment amount is important for predicting Novar’s cash flow as accurately as possible. This allows us to better estimate the offsets that will occur between the SDE++ advance payments and the final settlement, which can involve large sums. In addition, a reliable forecast helps us determine the strike price*.”

*The strike price is the threshold amount used to determine whether it is financially attractive to have a renewable energy facility generate power at a given time.

Last edited on October 12, 2026