Expanding Battery Value: From Energy Arbitrage to Carbon Value Optimization
The introduction of hourly matching fundamentally expands the role of grid-scale batteries—from simple energy time-shifting to enabling the time-shifting of carbon value. This shift creates entirely new business models beyond traditional electricity arbitrage.
Historically, grid-scale batteries have generated revenue by charging during low-price periods (typically daytime) and discharging during high-price periods (typically nighttime). Under an hourly matching framework, however, batteries can capture additional value by integrating time-stamped environmental attributes—specifically, Granular Certificates (GCEACs), a form of time-based Energy Attribute Certificates (EACs).
Temporal Value of GCEACs and the “Time Machine Effect”
During daytime hours, renewable generation—especially solar—often exceeds demand, resulting in an oversupply. As a result, the value of GCEACs associated with those hours tends to be relatively low. In contrast, during nighttime hours when renewable supply declines and demand remains, GCEACs become significantly more valuable.
Grid-scale batteries can arbitrage this temporal imbalance not only in electricity markets but also in carbon markets. By charging with low-cost, renewable-linked GCEACs during the day and discharging at night, batteries effectively “shift” environmental value across time. This can be described as a “time machine effect” for carbon value.
Carbon Value Creation Through Emissions Intensity Differentials
This model also creates additional value from a location-based emissions perspective. For example, if the grid emissions factor is 0.3 kgCO₂/kWh during daytime charging and rises to 0.5 kgCO₂/kWh during nighttime discharge, the battery effectively enables a 0.2 kgCO₂/kWh emissions advantage.
For end users, this means that even when consuming the same “renewable electricity,” the timing of delivery matters. Electricity supplied through this time-shifted mechanism results in lower reported emissions under the location-based method, enhancing the credibility and impact of decarbonization efforts.
The Importance of Market Rules and Standardization
To operationalize this model, robust market rules are required. These include systems for tracking GCEACs, transferring environmental attributes from charging to discharging, reallocating certificates, and ultimately transacting them with end users.
Efforts to standardize these mechanisms are currently being led by EnergyTag, which is developing global frameworks for time-based energy attribute tracking. These standards are essential to ensure transparency, integrity, and scalability of the market.
Application Model 1: Co-located (On-site) Renewable and Storage Systems
This model can be extended by co-locating batteries with renewable generation assets such as solar farms. Integrating generation and storage enables more efficient temporal shifting of both electricity and environmental value, enhancing overall project economics.
Similarly, installing batteries on the customer side (e.g., within industrial or commercial facilities) allows for more precise hourly matching and maximizes emissions reduction value.
Application Model 2: On-site PPA with Hourly Matching Services
Another application involves combining on-site solar and battery systems under a unified Power Purchase Agreement (PPA). In this configuration, providers can deliver not only electricity but also hourly matching services, directly contributing to the customer’s decarbonization outcomes and carbon accounting.
Application Model 3: Hybrid Renewable Portfolios with Storage
More advanced configurations include hybrid PPAs that combine solar and wind generation, supplemented by grid-scale batteries. By diversifying generation profiles and adding storage, these models can achieve a higher degree of temporal alignment between supply and demand.
Application Model 4: Unbundling and Reallocation of Energy and Environmental Attributes
A further evolution of this model involves unbundling electricity and environmental attributes and selling them to different customers. For instance, a customer may consume electricity without claiming its environmental attributes, allowing the associated GCEACs to be sold separately to another buyer.
Additionally, if a customer does not consume electricity during certain hours, the corresponding environmental attributes can be reallocated and sold to other customers. This increases market liquidity and enables more efficient allocation of carbon value, opening up new trading opportunities.
Looking Ahead: Designing for Commercialization
Hourly Matching Co., Ltd. and D-Sharing Co., Ltd. are currently advancing the design of these business models for commercialization. By integrating electricity markets with granular carbon accounting, hourly matching is poised to create a new paradigm in energy and environmental value markets.