How can you do hourly matching with monthly certificates?

Hourly Matching in Practice series

This blog post is part of our Hourly Matching in Practice series, which aims to help newcomers to this topic quickly get up to speed ahead of the changes to the GHG Protocol's scope 2 emissions guidance.

• Part 1: What is hourly matching and what does it mean for your business?
• Part 2: What is a high matching score?
• Part 3: How does hourly matching work with monthly certificates? (you are here)
• Part 4: How and why are businesses getting started with hourly matching?

How can hourly matching work without hourly certificates?

Hourly matching is the practice of evaluating whether your renewable energy purchases are aligned with your electricity consumption hour by hour, rather than just annually (see Part 1). Different factors such as asset type, mix of technologies impact your hourly matching score (see Part 2). How do energy suppliers come up with the hourly matching picture in the first place? In most jurisdictions, there is no centralised tracking of hourly clean energy, so how do utilities and energy suppliers do it? In order to ensure the credibility of hourly matching claims and ensure no double-counting, hourly matching requires connecting EACs and metering data.

The status quo

First, a quick primer. Energy Attribute Certificates (EACs) are the backbone of electricity tracking systems. You may know them as RECs in the US, GOs in the EU, NFCs in Japan, GECs in China, or REGOs in the UK, but we will use the catch-all term EAC for the rest of this post. EACs were established about 20 years ago, and are still the main instrument for tracking clean energy procurement to this day. They work as follows: when a renewable energy generator produces clean electricity, they get issued certificates that represent their generation. Companies can purchase these certificates and claim they're powered by renewable energy, reducing their reported carbon emissions (Scope 2). This all happens in parallel to the physical power market, where participants buy the physical electricity that powers their operations, as illustrated below:

A diagram of how EAC systems operate today.

Currently, most certificate systems operate on an annual basis. If you buy certificates that cover the entirety of your annual electricity consumption, you can claim to be "100% renewable powered" for that year. Here's the catch: annual accounting doesn't tell us when during the year that clean energy was actually generated and whether is aligns with when you consumed electricity. Timing can’t be underestimated when it comes to truly decarbonising the grid.

In an ideal world, certificate systems would immediately transition to issuing hourly certificates, giving us a much clearer picture of energy generation and consumption patterns. Unfortunately, outside of a few outliers such as PJM GATs, we're not quite there yet — but that doesn't mean we're stuck with the status quo.

The transition to hourly

In practice, the move to hourly certificates won't happen overnight. Different jurisdictions are at different stages of this transition, and some may take years to fully implement hourly tracking systems. So what do we do in the meantime?

The solution is to enrich the existing EACs with hourly production data from the renewable assets themselves. We already have the monthly certificates that tell us how much renewable energy was generated over the course of a month (but today, these monthly certificates can be used to cover any other month in the year). By adding the hour-by-hour generation profile from the actual solar or wind farm, we can create a much more detailed picture of when that renewable energy was produced, all while still working within the existing certificate framework.

This approach gives us the hourly matching transparency we need without having to wait for regulatory systems to overhaul their infrastructure. This new system is summarised in the diagram below:

How do you keep the EAC picture and the hourly matching picture in agreement?

If you're making hourly matching claims, you need to ensure that your EAC data and your metering data are telling the same story. After all, the last thing you want is for your certificates to say you have 100 MWh of renewable energy for the month while your metering data adds up to something completely different!

The rule for making credible claims: for any hourly matching claims, you must have access to both the EAC and its underlying metering data.

But how do you make sure these two data sources align? There are several methods for reconciling EAC data with metering data, but we recommend following the approach outlined in the 24/7 Coalition Technical Criteria. This method involves "spreading out" the monthly EAC across the hours of the month based on the actual generation profile of the renewable asset. In other words, you're giving each EAC a "shape" that reflects when the energy was actually produced.

💡Other standards like EnergyTag’s configuration 3 setup, or TUV SUD EE02 are also worth reading up on.

For example, if you have a monthly certificate for a solar farm, you'd distribute that certificate across the month following the sun's patterns: more energy allocated to sunny afternoon hours, less to night-time and cloudy days. This creates a consistent picture between your certificates and the reality of renewable generation. You can see some examples of how this works below:

This all sounds complicated, do I have to do this myself?

Your energy supplier can take care of this for you. They have the EACs and the metering data, so it is their job to take care of this on your behalf. As an end-consumer, you will simply receive a report with your matching score and carbon emissions, as mentioned in our first blog post.

Suppliers around the world are already publicly offering hourly matching products today. For instance, Smartest Energy provides these services in the UK, A2A has a product in Italy, and Jera is providing hourly matching in Japan. The market is already moving in this direction, and more suppliers are joining all the time. It is likely that your own supplier is working on an hourly offering, even if they have not started to offer it publicly yet. If you contact us, we can help point you in the right direction.

Start hourly matching today with EACs and metering data

In most jurisdictions, in order to be able to claim to be powered by a specific source of electricity (and claim the associated emissions benefits), companies need to have bought energy attribute certificates (EACs). As we transition from a world of monthly EACs to a world of more granular hourly EACs, we can use metering data to add an extra layer of transparency to monthly EACs. It’s important to make sure that the EAC picture and the metering data picture agree, and initiatives such as the 24/7 coalition define best practice on this topic.