Scale carbon free energy with clean transition tariff

As a leader in energy innovation, Google is helping build the systems needed to power a brighter future for all. They believe in energy solutions that benefit everyone, and are deeply committed to being a good neighbor by prioritizing affordable, reliable, and clean energy in the communities they call home.

Google’s track record over the last 15 years demonstrates this commitment. From 2010 to 2024, they have signed over 170 agreements to purchase more than 22 gigawatts of clean energy generation (i) and entered into agreements to invest over $3.7 billion in clean energy projects and partnerships. (ii) These efforts have allowed the company to maintain a 100% renewable energy match on a global basis every year since 2017 (iii).

As pioneers in computing infrastructure, they also focus on efficiency. Google’s data centers are some of the most energy efficient in the world, delivering over six times more computing power per unit of electricity than they did just five years ago. (iv) And this focus on efficiency extends to their products. Over a recent 12 month period, the energy footprint of the median Gemini Apps text prompt dropped by 33x and is equivalent to watching TV for less than nine seconds. (v)

Ultimately, Google's ambition is to run their operations on carbon-free energy, every hour of every day. By leveraging proven technologies and investing in cutting-edge research, Google is powering possibility everywhere they plug in.

The Clean Transition Tariff (CTT) is a new, scalable utility rate structure designed to accelerate 24/7 Carbon Free Energy (CFE) adoption. The CTT enables energy buyers like Google to partner directly with their utility to invest in the commercial deployment of advanced clean firm technologies (e.g., enhanced geothermal, long-duration energy storage, and advanced nuclear). The CTT is notably different from traditional green tariffs because it facilitates investment in additive, clean firm resources—resources the utility would not have otherwise been able to procure—by designing the capacity and other attributes with the utility's system needs in mind through integration with the Integrated Resource Planning (IRP) process. This structure ensures the investment both accelerates the utility's overall decarbonization and is beneficial to both the participating customer and all ratepayers. The participating customer covers the full incremental cost of the resource and in return receives full credit for the resource's energy and capacity value.

This precedent-setting tariff, jointly proposed by NV Energy and Google and approved by the Public Utilities Commission of Nevada (PUCN) in 2025, greenlit a 115 MW enhanced geothermal resource the utility had not previously committed to, providing a replicable blueprint for markets worldwide. This replicable model has since received global recognition and is now being explored or adopted by major electric utilities across the United States — including Duke Energy (North and South Carolina), Xcel Energy (Minnesota), Entergy Arkansas, Ameren Missouri, and I&M (Indiana)—to support Google's growing data centers, accelerate clean energy growth, and advance Google's ambitious 24/7 CFE goals.

Location of the initiative: Nevada, The USA

1. The total GW figure represents primarily PPAs, and includes some generation from targeted clean energy investments where Google also receives EACs. Actual generation may vary from the signed amounts based on changes during construction or project terminations

2. The total GW figure includes generation from targeted clean energy investments. Actual amounts funded and generation developed may vary from the amounts anticipated when the agreements were signed.

3. For details about the calculation, refer to the Methodology section in the Appendix of the Google 2025 Environmental Report.

4. According to Google’s platform-neutral measurement analyzed over a five-year period from 2019–2024.

5. A point-in-time analysis quantified the energy consumed per median Gemini App text-generation prompt, considering data from May 2025. These findings do not represent the specific environmental impact for all Gemini App text-generation prompts nor are they indicative of future performance. The results of the analysis from May 2025 were compared to baseline data from the median Gemini App text-generation prompt in May 2024. Energy per median prompt is subject to change as new models are added, AI model architecture evolves, and AI chatbot user behavior develops. The data and claims have not been verified by an independent third-party. The equivalency assumes a TV uses 100 Wh of energy per hour, per “How many watts does a TV use?,” Energysage, November 2024, accessed July 2025.

NV Energy was the first utility to operationalize this new approach through an energy supply agreement that will add 115 MW of around-the-clock enhanced geothermal power to Nevada’s grid to power one of Google’s data centers in Nevada.

How it works:

1. Joint Resource Identification and Planning:

   The utility and the large power user (e.g., Google LLC) collaborate, analyzing the utility's system needs and the customer's load profile, to mutually identify additive clean firm resources that accelerate shared sustainability goals and provide system benefit.

2. Customer Commitment & Value Exchange:

   The large power user agrees to cover the full incremental cost (at a premium) of the mutually identified clean resource. In return, the customer receives full credit for the resource's energy and capacity value against the standard utility rate.

3. Regulatory Vetting, Approval, & Procurement:

   The utility regulator (e.g., The Nevada Public Utilities Commission (PUCN)), as applicable, reviews and approves both the energy supply agreement and the resource plan with the new resource incorporated, ensuring other ratepayers are protected from financial risk or cost shifting. Secured by this regulatory approval, and the underlying financial commitment, the utility then contracts, procures, or builds the new clean capacity resource (e.g., enhanced geothermal or long-duration storage).

4. Mutual Benefits Realized:

   Upon commercial operation, the customer secures a guaranteed 24/7 clean energy supply and meets sustainability goals. Meanwhile, the state, utility, and all ratepayers benefit from accelerated clean energy deployment, economic development, and improved grid reliability from the new, firm capacity, with the financial risk of commercializing the new resource fully mitigated by the participating customer's long-term commitment.

The CTT framework is now also being explored in Indiana, Minnesota, and Missouri, with wider adoption efforts underway across several markets:

• In Indiana, the Commission approved a settlement that includes a commitment from Indiana Michigan Power to work with stakeholders to develop a CTT.

• In Minnesota, the development of a CTT is now legislatively directed, and Xcel Energy has expressed its willingness to advance this model.

• In Missouri, Ameren has recently filed a new CTT proposal for regulatory review and approval.

Sustainability impact

Climate

This initiative primarily targets Scope 2 emissions by securing 115 MW of additive clean firm energy (enhanced geothermal or EGS) to help the customer reach its 24/7 CFE goal. The CTT structure represents an enabling impact on climate by addressing the most difficult non-solar hours of grid decarbonization. It successfully draws private capital into early-stage CFE technology that the utility would not otherwise procure due to cost concerns.

The foundational CTT approach is a globally recognized, replicable clean energy model, now being adopted by at least six major U.S. electric utilities. This rapid scaling of an additive clean energy model magnifies the impact potential of CFE acceleration in the U.S., leading to widespread downstream reductions in Scope 2 emissions. The initiative also impacts Scope 3, Category 2 (Capital Goods) by accelerating the commercial viability and future cost reduction of clean energy infrastructure.

Nature

The Clean Transition Tariff (CTT) has significant indirect benefits for nature and the environment:

• Enabling New Clean Capacity: The CTT enables the development and deployment of new, additive carbon-free energy (EGS)—capacity that NV Energy would not have otherwise implemented due to concerns over cost

• Driving Down Future Costs: This privately funded investment expands the knowledge base and is expected to drive down the costs of future clean energy investments. Future utility investments in clean firm energy (CFE) may be less costly due to these initial learnings.

• Emissions and Ecosystem Protection: The resulting deployment of CFE reduces system-wide reliance on fossil fuels, which lowers emissions. Lower emissions in turn help to stabilize ecosystems and moderate the intensity and frequency of extreme weather events, which are increasingly damaging to natural ecosystems

• Resource Diversity and Reliability: Adding EGS to the resource portfolio provides resource diversity, reduces fuel supply risks, and increases overall reliability of the system

• Establishing a Replicable Model: This foundational CTT approach has since paved the way for a replicable model that has received global recognition and is being adopted by at least six major U.S. electric utilities (including Duke, Xcel, and Entergy) to accelerate clean energy growth nationwide, magnifying the impact potential of CFE acceleration

Social

The Clean Transition Tariff (CTT) creates positive, large-scale social and economic impacts:

• Ratepayer Protection and Equity: The CTT structure ensures that non-participating electric ratepayers are fully protected from all premium costs associated with the new resource. The participating customer (Google) bears the full premium costs and assumes risk of cost-overrun or project failure

• Grid Reliability, Diversity, and Future Cost Mitigation: By introducing a clean, firm, and flexible resource like EGS to the system, the CTT enhances resource diversity and improves overall system reliability. Furthermore, this investment in next-generation technology expands the knowledge base and can potentially drive down the costs of future utility investments in clean energy, as the EGS resource is currently too costly for the utility to approve on its own

• Accelerating Clean Industrial Growth: The mechanism accelerates the roll-out of new clean technologies needed for a decarbonized grid. This is achieved by attracting crucial private capital to construct operational projects in the field, moving technological concepts to reality faster

• Economic Benefits and Job Creation: This type of private investment promotes regional economic growth. Specifically, the EGS technology can draw workers, and skill sets from the oil and gas sector, facilitating a transition for a skilled workforce

• Establishing a Scalable Model: The CTT structure has already proven to be a globally recognized, replicable clean energy model, currently being adopted by at least six major U.S. electric utilities (including Duke Energy, Xcel Energy, and Entergy Arkansas) to expand clean energy capacity. If widely adopted across electricity markets, this mechanism will continue to accelerate the roll-out of new technologies, magnifying the impact potential of CFE acceleration

Business impact

Benefits

The Clean Transition Tariff (CTT) provides key advantages to the business beyond general sustainability goals, acting as a crucial tool for operational resilience and strategic growth:

• Operational Resilience through Clean Capacity: The CTT allows the customer (Google) and utility to intentionally select resources that provide clean capacity (like EGS) to support grid reliability and directly enable the customer to achieve its ambitious 24/7 CFE goals. Without the CTT, achieving the customer's goal of being 24/7 CFE by 2030 would be impossible given the current utility resource mix

• De-risking Long-Term Energy Supply: The CTT ensures the customer can secure a guaranteed, long-term supply of clean, firm power (a 15-year ESA is secured by the mechanism), effectively hedging against future price volatility and scarcity associated with standard bundled energy and capacity costs

• Optimized Resource Investment via Integration with the Integrated Resource Planning Process: The requirement for Incorporation into Utility Integrated Resource Planning (IRP) ensures that customer-specific investments are efficient and targeted. Consideration of existing and planned utility investments prevents redundant spending and ensures the CTT resource complements the grid's actual needs, maximizing the value per dollar invested and the broader power system benefits

Costs

The Clean Transition Tariff (CTT) is a mechanism designed to facilitate investment in additive clean firm energy capacity by aligning corporate clean energy procurement with utility resource planning while insulating non-participating customers from financial risk.

• Investment required (Customer financial obligation): The participating customer (Google) assumes this financial risk and pays the full premium cost of the resource via a premium CTT Energy Rate

• Impact on operating costs (Ratepayer Protection/Cost Exposure): There is no cost-shift to non-participating ratepayers. The CTT ensures the customer pays the premium for the new power while receiving a corresponding energy and capacity credit against their standard bundled rate, ensuring other ratepayers are protected from the higher price of the advanced technology

• No Direct Subsidy: The CTT itself is a procurement structure using private capital to catalyze the investment, not a subsidy. The core value is transferring the premium cost risk from the utility/ratepayers to the customer

• Risk Transfer and Dependencies: The customer assumes the risk, which is dependent on the CAPEX and risk profile of the advanced technology. If the project fails, the ESA is voided, and penalties will accrue to the utility

Impact beyond sustainability and business

Co-benefits

The Clean Transition Tariff (CTT) initiative generates co-benefits that positively impact people and society beyond general business and sustainability:

• Workforce and Economic Transition: The underlying Enhanced Geothermal System (EGS) technology can draw workers, and skill sets from the oil and gas sector, facilitating a just transition for a skilled workforce.

• Expanded Resource Access: The mechanism enables investment in next-generation technologies like Enhanced Geothermal Systems (EGS) that would otherwise be financially inaccessible. By addressing the high-cost barrier with private capital, the CTT vasty expands the potential for a clean, firm power source across electricity markets.

Typical business profile

Large-scale energy buyers with emissions reduction goals.

Approach

How it works:

• Joint Resource Identification and Planning: The utility and the large power user (e.g., Google LLC) collaborate, analyzing the utility's system needs and the customer's load profile, to mutually identify additive clean firm resources that accelerate shared sustainability goals and provide system benefit.

• Customer Commitment & Value Exchange: The large power user agrees to cover the full incremental cost (at a premium) of the mutually identified clean resource. In return, the customer receives full credit for the resource's energy and capacity value against the standard utility rate.

• Regulatory Vetting, Approval, & Procurement: The utility regulator (e.g., The Nevada Public Utilities Commission (PUCN)), as applicable, reviews and approves both the energy supply agreement and the resource plan with the new resource incorporated, ensuring other ratepayers are protected from financial risk or cost shifting. Secured by this regulatory approval, and the underlying financial commitment, the utility then contracts, procures, or builds the new clean capacity resource (e.g., enhanced geothermal or long-duration storage).

• Mutual Benefits Realized: Upon commercial operation, the customer secures a guaranteed 24/7 clean energy supply and meets sustainability goals. Meanwhile, the state, utility, and all ratepayers benefit from accelerated clean energy deployment, economic development, and improved grid reliability from the new, firm capacity, with the financial risk of commercializing the new resource fully mitigated by the participating customer's long-term commitment.

Stakeholders involved

The implementation of the Clean Transition Tariff (CTT) was a highly collaborative process involving the regulator, the customer, the utility, and the technology partners, each playing a crucial and distinct role:

• Google (The Customer): The customer was the initiator and driver of the mechanism. Google proposed the original tariff concept, established the strategic priorities, assumed the full financial risk of the clean energy resource, and ultimately filed the Energy Supply Agreement (ESA) in partnership with the utility.

• NV Energy (The Utility): The utility co-developed the final tariff mechanism with the customer and managed the regulatory process. NV Energy executed the Power Purchase Agreement (PPA) with the supplier for the 115 MW Enhanced Geothermal System (EGS) capacity, acting as the intermediary to deliver the power to Google.

• Fervo Energy (The Technology Developer and Provider): The technology developer is contracted to deliver the core resource, supplying the 115 MW EGS capacity by 2030.

• Public Utilities Commission of Nevada (PUCN) (The Regulator): The regulator provided regulatory oversight and governance. The PUCN directed continued discussions on the CTT and gave final approval authority over the ESA to ensure it is in the public interest.

• Other Regulatory Parties (Public Interest Oversight): Key stakeholders in the regulatory process, such as the Regulatory Operations Staff at the PUCN, the Nevada Bureau of Consumer Protection, and environmental non-governmental organizations (ENGOs), played a critical role in the regulatory docket by participating in the process and ensuring the CTT mechanism aligned with the public interest and would not negatively impact non-participating customers.

Key parameters to consider

• Initiative Maturity: The Clean Transition Tariff (CTT) is an Early-Stage/Novel Regulatory Structure. It is a new tariff based on a proposal originally made by the customer (Google) and is an evolution of corporate procurement approaches. The mechanism represents a "new approach" for customer investment in grid decarbonization.

• Implementation Timeline: The process involved proposing the CTT in a 2022 general rate case, subsequent discussions directed by the Commission, and the filing of the CTT ESA. The underlying EGS resource (Corsac Project) is expected to come online in 2030.

• Average Lifetime: The specific Google CTT Energy Supply Agreement (ESA) has a term of 15 years.

• Technical Constraints: The CTT mechanism itself has no technical constraints, but it is specifically designed to overcome the economic constraint of the high costs associated with early-stage, clean firm capacity (EGS) that utilities are hesitant to procure otherwise.

• Regulations (Critical Parameters): The CTT is structured to meet three core priorities: (1) facilitate procurement in technologies that deliver clean capacity; (2) support state energy policy (Nevada's 100% CFE by 2050 goal) ; and (3) ensure the participating customer bears all premium costs. It provides a pathway for existing customers to accelerate decarbonization.

• Other (Ratepayer Protection/Risk Transfer): The CTT is explicitly designed to ensure full ratepayer protection from all premium costs. The customer assumes the risk, and if the project fails, the CTT ESA will be voided, and penalties will accrue to the utility.

Implementation and operations tips

Challenge: Regulatory Novelty and Need for Customization- The CTT is a new tariff and a "new approach" that requires significant regulatory engagement and approval. Scaling requires customizing the mechanism to fit varying state energy regulatory environments.

Tip for Success: Prioritize IRP Alignment for Scalability- Ensure the CTT always requires incorporation into the utility's Integrated Resource Plan (IRP). This alignment embeds the customer's strategic investment into the core planning process, providing regulatory stability and demonstrating that the clean capacity complements the grid's actual, hourly needs.

Challenge: Internal Utility Silos and Change Management- The capacity crediting and procurement structure of the CTT is entirely new, requiring multiple divisions within the utility to work with the customer and lean in in new ways. The utility must overcome internal silos to support the new capacity crediting model and also help identify resources that benefit both the customer and the system.

Tip for Success: Establish Cross-Functional Project Leadership- Dedicate project leads who bridge traditional departments (e.g., Regulatory, Energy Supply, Finance, and Customer Service) early in the process. Create shared goals across these divisions, rewarding teams not just for risk mitigation but for innovative resource identification (e.g., finding the EGS project) that successfully balances the customer's 24/7 CFE goals with the overall system's reliability needs. This ensures the utility views the CTT as a strategic asset for the grid, not just a contractual obligation.