# Why Annual Averages Hide the Value of a Hybrid Project

Author: Charles Haworth · Published: 2026-10-17 · URL: https://charleshaworth.com/why-annual-averages-hide-hybrid-value/ · Category: Renewable Energy

A renewable project becomes bankable in specific hours, not in an annual average. Test hybrid configurations against the value and constraints of those hours.

The renewable projects I work on are getting more complex. More are exposed to merchant markets, grid constraints are tighter, and hybridisation is becoming standard practice.

Yet many projects are still designed and modelled around annual averages.

That is no longer enough. A project creates value in particular hours: when it generates, when the offtaker values the power, when the grid can accept it, and when storage can shift it into a higher-value window.

That distinction sounds technical. It is actually commercial.

Annual energy is useful, but it averages very different commercial moments. It can hide the mismatch between generation and demand, flatten the cost of curtailment, and make a battery look either essential or irrelevant without testing what it does in the hours that matter.

For a developer with a marginal project, that is a dangerous shortcut. Development capital is already sunk. The investment committee needs a clear answer: is there a configuration that clears the bar, or not?

## Proof: the annual average can tell the wrong story

Consider a developer with a wind-only design that is close to, but below, the financeability hurdle.

On an annual view, the project produces a respectable energy number. The conclusion looks obvious: the site is simply not strong enough.

But that conclusion is premature.

The annual number cannot show whether solar would produce in higher-value hours, whether storage could move output into a better window, or whether a different combination would use the existing connection more effectively. It cannot distinguish a site that has no route to bankability from one that has been modelled with the wrong level of detail.

The important question is not “how much energy does it produce in a year?”

It is “what is each hour worth, and what configuration captures that value?”

That is where the economics become visible.

Hourly chart showing wind strongest overnight and in the evening, solar peaking at midday, offtaker value lowest before dawn and peaking in the evening, and illustrative battery dispatch

_Illustrative 24-hour profiles and battery dispatch. Not project data._

## Principle one: time is part of the product

Electricity is not a single commodity in a spreadsheet. A megawatt-hour at one time can be worth something very different from the same megawatt-hour at another.

That means the design process has to start with the commercial shape of the project. What does the offtaker need? Which hours carry value? What constraints sit behind the connection? Where does generation fail to align with the revenue opportunity?

If those questions are not in the model, the model is not yet ready to support a financeability decision.

This is not a call for more complexity for its own sake. It is a call for the right complexity. The job is to remove false confidence, not to create a larger spreadsheet.

## Principle two: components must earn their place

A hybrid project is not a shopping list.

Solar, wind and storage each change the generation and dispatch profile. Their value depends on the site, the connection, the offtaker and the commercial rules. Adding a fixed proportion of solar or choosing a battery duration by convention may create a plausible design. It does not prove it is the best design.

Every component should earn its place in the economics.

That means testing alternatives before capital is committed. Some sites will not justify more equipment. Others will reveal a configuration that changes the investment case. Both outcomes are valuable because both replace assumption with a decision.

## Principle three: bankability is a configuration problem

Developers often treat design and commercial work as separate streams. One team estimates production. Another handles the offtaker conversation. Another builds the financial model.

The investment committee sees the outputs at the end.

By then, the most useful design choices may already feel fixed.

A better approach is to treat the project as one connected optimisation problem. Model the generation profile, commercial value, constraints and dispatch together. Then compare configurations against the financeability threshold.

The result is not an abstract technical optimum. It is a commercial recommendation that can be explained clearly: this is the configuration, this is why it creates value in the relevant hours, and this is what still needs to be proven.

## Process: how I would test the decision

The practical sequence is straightforward.

First, define the hourly commercial problem. Build the offtaker pricing shape and the relevant grid and connection constraints into the analysis.

Second, model the base case honestly. A wind-only or solar-only case is not a straw man. It is the benchmark against which the hybrid alternatives must earn their capital.

Third, test the combinations. Change capacity, storage and dispatch assumptions. Look for the trade-offs rather than a preselected answer.

Fourth, bring the result back to the investment question. Does a configuration cross the financeability threshold? If not, what is missing? If it does, which assumptions are critical enough to validate before the next commitment?

This is the problem we built [Converge Hybrid](https://converge-hybrid.com) to solve: bringing generation, offtaker pricing, grid constraints and battery dispatch into one hourly model, so a developer can test wind, solar and storage configurations before committing capital.

That process gives the board a better conversation. Instead of debating an annual average, it can debate the value that the project can actually capture.

## The decision hidden inside the average

There is no virtue in hybridising every project. The point is to know whether hybridisation changes the economics before the market, a supplier or an internal rule of thumb makes the choice for you.

The best renewable projects are not necessarily those with the largest annual yield. They are the projects whose design matches the hours when the system values power.

For any developer looking at a project that will not quite pencil, the next question is simple: what does the annual average hide?