Understanding annual, monthly, and hourly matching resolutions

This article explains what matching resolutions are, why they matter, and how the Granular Energy platform supports annual, monthly, hourly, and sub-hourly matching in one place.

What is a matching resolution?

When energy suppliers and consumers want to understand how well their renewable energy supply aligns with their demand, they need to choose a time window over which to measure that alignment. This time window is called the matching resolution (sometimes also referred to as time granularity).

For example:

An annual matching resolution checks whether the total volume of renewable energy supplied over the year equals total consumption over the year.
A monthly matching resolution does the same check, but separately for each calendar month.
An hourly matching resolution does it for every individual hour of the year.

The finer the resolution, the more transparent information.

Why does the matching resolution matter?

The matching resolution directly affects the matching score, the key metric Granular Energy uses to express how renewable energy supply aligns with demand.

When measured at an annual level, matching scores tend to be higher, because surpluses in one moment can offset shortfalls in another. When measured hourly, the same portfolio may look quite different: excess solar generation at midday cannot compensate for uncovered demand late in the evening.

This is not a flaw in the data, rather a more accurate picture of what is physically happening on the grid.

So far, reporting and industry standards requires annual matching. In the UK, for example, the compliance period runs from 1 April to 31 March. However, regulators, corporate buyers, and frameworks such as the GHG Protocol Scope 2 Guidance are starting to ask suppliers and consumers to demonstrate alignment at hourly granularity. This reflects a growing recognition that hourly matching can confirm that clean energy was actually generated at the same time it was consumed.

More granular matching also has a practical role in decarbonising the grid: by making supply-demand imbalances visible at the hour level, it creates actionable signals for investments in storage, demand-response, and additional generation capacity.

How hourly matching and different resolutions are used in practice

Not all customers ask for the same matching resolution. While most are still expecting yearly or monthly matching, a handful are starting to ask for hourly matching. One important element to note here: while there is generally an expectation of 100% annual matching for standard green tariffs, ‘hourly matching’ tariffs do not entail a requirement for 100% matching at that level - rather the hourly visibility.

Some customers are starting to ask for hourly matching to report to standards (GHG Protocol updates to come, UK GBC, 24/7 Coalition), investors, meet sustainability targets, or follow national regulatory frameworks that reference hourly matching. But today, even following the most stringent reporting obligations, there are no hard requirements to achieve 100% hourly matching - as this reporting is voluntary. The GHG Protocol and equivalent hourly reporting frameworks require energy buyers to measure and report on their hourly matching score. The distinction matters: knowing your score at hourly resolution is the ask; achieving a perfect score is not.

This is a common source of confusion in the market, and worth making explicit: a supplier who delivers 78% hourly matching is fully compliant with these frameworks as long as that figure is accurately calculated and disclosed.

Typically all customers that are on an hourly matching contract will be allocated 100% on the annual level to ensure that they comply with all of their reporting requirements.

How contracts typically reflect this

Contracts that include hourly transparency provisions tend to fall into one of two structures:

transparency-only contracts: the contract guarantees that the hourly matching score will be calculated and reported, without setting a minimum percentage. The focus is on transparency.
Minimum-score contracts: The contract sets a minimum hourly matching score, commonly 70%, 80%, or 90%, which the supplier commits to maintain.

In both cases, the Granular Energy platform allocates certificates in a way that keeps the hourly matching score at or above the contracted minimum, while simultaneously ensuring the target on an annual basis, usually 100%.

How the Granular Energy platform handles multiple resolutions

The Granular Energy platform is designed to support all common matching resolutions in a single environment, covering annual, monthly, hourly, and sub-hourly (e.g. 30-minute, 15-minute, or 5-minute intervals).

This matters in practice because energy portfolios are rarely uniform. A supplier may have some customers with smart meters providing hourly data, others with monthly billing data, and legacy contracts settled annually. The platform handles this by allowing data to be imported at any granularity and then matching high-granularity generation data to lower-granularity consumption data where needed — so you do not have to maintain separate environments.

Selecting the matching resolution in the platform

In the Portfolio and Consumer views, as well as in the End-Consumer Dashboard, you can switch between available time granularity options using the resolution selector. The options displayed depend on:

The granularity of your uploaded data: depending on the source data granularity, only the available granularities will be displayed, the others greyed out. For example, if you have monthly metering data, Hourly and Daily matching resolutions will be greyed out.
Your account settings: granularities are enabled for your environment according to location, as some markets and regions have 5-minute intervals data, others 15- or 30-minutes. Contact your Customer Success Manager if you need additional options activated.

A filter in the Portfolio view also lets you quickly select consumers or generation assets that have hourly or sub-hourly data, allowing you to focus your analysis on the most granular segments of your portfolio.

How you can explore the matching score at different granularities

The Compare tab in the Portfolio view will show how much percentage of the consumption was covered under that different granularities.

For standard green tariffs, the score will typically be 100% on an annual level, and drop progressively as each time step is more precise, due to the potential excesses and shortfalls in each interval. Note, the finest granularity visible depends on the available data.

Understanding the difference of matching volumes and volumes in excess

The % score represents how much % of the consumption was covered by generation in the same time interval. These volumes are described as Matching. Generation volumes that have been allocated to a customer that exceed the consumption at that time interval are called in excess.

Volume that is in excess on the hourly level can be Matching on the monthly level: for example if you allocate a lot of solar to a customer it is likely that there are non-matching excesses of renewable energy at noon. However looking at the monthly granularity, the generation has happened in the same month as the consumption, hence the volumes are matching.

The graph below shows a detailed analysis of the hourly matching score of a customer

The dark horizontal line describes the consumption of the customer over two days from January 1 to January 2. The bars represent the allocated renewable energy. The numbers on the button represent the breakdown for 01.01 at 22:00h.

All of the volumes under the consumption are considered Matching. In this case they represent 75.8% of the total volume. All of the volumes above the consumption line are in excess. As they do not match the consumption at that time, they do not count towards the matching %.

Looking at the same data under annual granularity below, we can see that the score is 100%, as the excesses from noon on the screenshot above were counted towards some hours where there was no renewable generation.

Uploading data at different granularities

Data can be imported at any granularity — either via CSV upload in the platform interface or via the API. When uploading via API, the granularity is inferred automatically from the interval structure of your file, but can also be set explicitly using an optional query parameter. See the API documentation for details.

Tips & things to know

Lower matching scores at higher granularity are expected — they reflect a more accurate picture of supply-demand alignment, not worse performance.
Mixing granularities is supported: You can allocate hourly generation data to consumers with only monthly or annual consumption data. The platform handles the aggregation.
The GHG Protocol Scope 2 revision is expected to require hourly matching for credible market-based emissions claims. If your customers are working towards this standard, the hourly matching capabilities in the platform are directly relevant.
Sub-hourly data (30-minute, 15-minute, 5-minute) is supported for regions where this level of metering is available, but may need to be enabled by your Customer Success Manager.
For a practical walkthrough of how the matching score and other key metrics are displayed at different resolutions, see the article on Navigating the End-Consumer Dashboard.