How should I value wind generation at a site that already has solar?

The short answer

At a site with existing solar, wind value depends on the demand and supply remaining in each relevant interval. Wind generation cannot automatically be valued as if it displaces electricity purchases that solar already avoids. Use the combined chronology and actual export or storage arrangements to assess the incremental contribution.

Establish the existing operating baseline

Collect demand and solar generation on consistent time intervals, with meter boundaries and missing periods identified. Record any existing storage operation and export restrictions without assuming compatibility with new wind equipment.

Separate a measured operating baseline from a simulation of planned solar. Both can be used, but their evidence and uncertainty differ. The wind comparison should state which baseline it uses.

Calculate the remaining opportunity

For each supported interval, identify residual demand after the existing system's contribution and account for any documented storage or control behaviour. Compare wind generation with that remaining demand, then value surplus according to an evidenced route.

Do not assume wind and solar always complement each other. Their relationship depends on local weather, seasons and site demand. A high combined annual total can coexist with surplus in some periods and deficits in others.

Include integration and alternatives

Compare the incremental useful energy with the complete cost and constraints of adding wind. Electrical interfaces, control responsibilities and any third-party storage require configuration-specific review. An attractive timing pattern is not proof of system compatibility.

The handover should show the baseline, combined interval model and separate value of consumed and surplus wind energy. This helps the buyer judge the addition on its actual marginal benefit rather than assigning the full retail electricity price to every wind kWh regardless of what the existing solar system already supplies.