EnergyTag‘s Head of US Policy, Alex Piper, testified before the Illinois House Executive Committee during its subject-matter hearing on Data Center Energy Use. 

In his testimony, he explained why a transition to hourly accounting is critical to restructure market incentives towards around-the-clock clean energy investments and deployment. Today’s accounting rules will not efficiently drive the clean energy transition, which will continue to burden our shared grid and on Illinois ratepayers.

See the full testimony below.

Testimony from April 15, 2026 at Illinois House Executive Committee

Alex Piper’s Testimony : 

Thank you Chair Williams and members of the committee for the opportunity to speak today. My name is Alex Piper, and I am the Head of US Policy for EnergyTag, a global non-profit with technical expertise in clean energy markets, hourly clean energy accounting and tracking infrastructure, and corporate energy procurement. In short, we are around-the-clock clean energy experts and advocates.

Today’s clean energy and capacity markets are designed for yesterday’s challenges. They incentivize cheap renewable purchases, but they also drive investment into gas as firming capacity for the grid. In today’s system, companies purchasing renewable energy can make bold zero emissions claims, while their actual operations may still rely heavily on gas capacity. This is expensive, inefficient, and pollution-intensive.

Enter, hyperscale data centers: massive and near-constant loads — a new challenge for grid reliability and the clean energy transition. This moment introduces yet another opportunity for Illinois to demonstrate its clean energy leadership:

As the General Assembly considers policy approaches to address data centers’ impacts on grid affordability, pollution, and reliability, the accurate accounting of new clean energy should remain front and center to that conversation. As Director Granahan and others have mentioned, this massive around-the-clock demand from data centers highlights the need for around-the-clock clean energy supply and flexibility to enable a fully decarbonized power sector in Illinois.

To get there, we need a shift from annual to hourly accounting. “Hourly accounting” of clean energy is the principle that an energy user must ensure that the clean energy powering the grid they are claiming with a paper certificate is actually produced by a facility in the same hour that the user consumed power on the grid. In this way, the accounting more accurately reflects the real timing of energy generation and consumption – the way power markets already work. When clean energy accounting does not reflect the physical reality of generation and consumption, inefficient price signals are sent and investments are made in facilities that do not support clean grid reliability and affordability.

It is also crucial that data centers “bring their own power” in order to alleviate impacts on working families and small businesses. But any “bring your own power” proposals that use annual accounting could allow daytime solar to quote – unquote “power” a new data center all day and night. 

100% annually matched power — using only one resource type, such as a solar only contract — can equate to as low as 40% hourly clean energy matching across the year. The other 60% of hours could still be powered with gas and other expensive electricity and still be considered “clean” under annual accounting.

This is a fundamental mismatch between the clean energy deployed and the real energy usage of data centers. International Energy Agency analysis shows this annual mismatch can drive costs up for everyone by requiring more unnecessary gas backup to be built — whereas when corporates bring hourly matched power, it mitigates the need for ratepayers to subsidize balancing resources. This contributes to a more efficient, and overall cheaper, electricity grid. Any “bring your own power” requirements that do not adopt hourly accounting risks continuing to burden ratepayers with costs for balancing the grid, while letting the largest energy users off the hook.

To be clear, annual accounting served to get clean energy markets off the ground and seed early investment in renewables. And in response, renewable costs have plummeted. We now need to scale innovative technologies like energy storage and “clean firm” generation, such as geothermal and nuclear, that can produce clean energy all the time. 

Hourly accounting is what generates the necessary price signals to drive investment and deployment into these newer clean energy technologies. When we value where and when clean electricity is produced, we begin to address the underlying challenges of today’s market, and we can more effectively respond to the emissions and economic challenges of rapid data center demand growth. 

Hourly accounting is highly feasible. International Energy Agency research demonstrates that meeting 80% hourly matching is economically feasible in the US today using just wind, solar, and storage. 

In fact, US tech companies are the one leading the charge on hourly accounting and matching today. Iron Mountain data centers are already tracking and matching clean energy on an hourly basis at 100 locations across the US. Google is leading the way by pairing new data centers with new clean energy capacity and hourly accounting, such as their recent deal in Michigan to bring 2.7 GW of new clean energy, storage, and demand flexibility. EnergyTag has documented over 10 terawatt hours of hourly matched clean power — about as much electricity as is consumed by Washington DC over an entire year. 

Software providers are already helping utilities and energy buyers easily understand and optimize those 10 terawatt hours of clean energy matching. And the Granular Certificate Trading Alliance, a consortium led by Microsoft, Google, Constellation, AES, and LevelTen Energy, is already running monthly auctions for hourly clean energy certificates in PJM. 

Finally, key legislation and standards worldwide are quickly adopting hourly accounting. The US 45V clean hydrogen tax credit requires hourly accounting to demonstrate clean electricity usage, and the European Carbon Border Adjustment Mechanism (or CBAM) now does the same for products imported into the EU. The Greenhouse Gas Protocol, which sets emissions reporting standards for companies around the world, plans to adopt hourly accounting for electricity consumption by next year.
Hourly accounting is doable and must be a component of any policy focused on data center demand and clean energy usage. Leader Hoffman has introduced the Advanced Technology Leadership Act, HB 5607, that does just that. I urge the Assembly to consider how hourly accounting can be implemented in response to this critical moment. Thank you again, and I am happy to answer any questions you may have.

 (Note: These statements were delivered orally, and while the core message remains unchanged, some wording may differ slightly from the spoken testimony. Hyperlinks have been added for context.)