Grid Resilience Solution

Industry-led solution improves grid resilience and recovery

Grid Assurance is the proactive, industry-led recovery solution that addresses the need to rapidly restore critical bulk electric system (BES) components damaged in high-impact events with a dedicated inventory of difficult-to-obtain assets. This provides subscribers with a certain, cost-effective means to expedite BES restoration efforts, adding incremental, dedicated spares for the industry.

Grid Assurance subscribers can confidently plan for quick restoration when they know their shared inventory of critical transmission equipment is in proper working condition, where and how it is stored, how it is to be delivered and the estimated time to deliver it to impacted sites.

Vital, long lead-time transmission equipment

Subscribers have access to a supply of long lead-time (up to two years) transmission equipment and will avoid supply chain constraints.

Current product offerings include extra high voltage transformers, circuit breakers and bushings. Additional product offerings are expected in 2023.

Transformer inventory

EHV transformers

Grid Assurance’s current inventory focuses on 230kV and higher transformer classes. The current inventory supports seven ratings classes, with designs and specifications built to support a range of transmission grids.

Circuit breakers

EHV circuit breakers

The current inventory addresses three EHV ratings, with amps and kA ratings able to accommodate many utilities’ networks.


EHV bushings

EHV transformer bushings inventory covers a wide range of transmission voltages.

Expedited delivery when it matters

The aftermath of a significant grid outage is often chaotic. Time is of the essence when companies need to replace critical equipment. Even if another utility has a replacement transformer and it can be transferred out of state, it can take many weeks or months to gain approval from rail operators to ensure that all clearances are met, and the unit can be safely transported. Obtaining a new transformer from a manufacturer, many of which are located outside the U.S., can take 12-18 months including submitting a bid, testing, transportation and site setup.

Grid Assurance can simultaneously deliver one or multiple extra high voltage (EHV) transformers

Grid Assurance’s solution:


Projected delivery time to event site(s) after catastrophic event.


Other options can’t match up

9-16 WEEKS

3rd party EHV transformer delivery time for one transformer to a single significant event site.

1 YEAR +

New EHV transformer delivery time to a single significant event site.

Comparison of industry spare equipment programs

Only one option provides utilities with a stockpile of critical long lead time assets and high confidence restoration plans that can be relied upon and executed.
Industry Spare Equipment ProgramsGrid Assurance logoOther
Incremental, dedicated domestically stored inventoryCheckmarkNone
Preplanned transportation & delivery logistics plansCheckmarkNone
Pooled assets: certainty of availabilityCheckmarkNone
Known, secure domestic warehouse storage away from impacted sitesCheckmarkNone
Dedicated team to execute plansCheckmarkNone
Cost certainty & transparencyCheckmarkNone
Regulatory clarityCheckmarkCheckmark
Known condition & warrantyCheckmarkNone
Promotes industry standardizationCheckmarkNone
Analytical modeling tools to define needs for large scale eventsCheckmarkNone
Capital investment earns returns NoneCheckmark
Event agnosticCheckmarkNone

Click to read more about Grid Assurance benefits

Incremental, dedicated domestically stored inventory

Keeping stores of dedicated critical transmission equipment to respond to high-impact, low-frequency (HILF) events is a best practice modeled after other successful inventory stockpiling programs including those of the healthcare, military, oil drilling and nuclear power industries.

Preplanned transportation & delivery logistics plans

Subscribers to Grid Assurance do not have to wait on rail operators or local and state authorities to approve a plan to move their assets. Knowing the exact location of the assets allows Grid Assurance and subscribers to develop over-the-rail and over-the-road plans that can be preapproved by railroad, state and local authorities to move the transformer from the rail siting location to the impacted site.

Grid Assurance has done all this work up front and has detailed playbooks with routes that have been approved. The routes are also reviewed every 12-18 months with the rail operators to ensure they are still valid and updated when necessary.

Pooled assets: certainty of availability

Grid Assurance maintains a secure inventory of equipment to provide certainty of availability and ensures assets are operational and can be expeditiously delivered to impacted sites. Grid Assurance pools the needs of multiple companies, which allows transmission owners to share in this dedicated inventory and reduce the cost for providing this necessary service.

Known, secure domestic warehouse storage away from impacted sites

Grid Assurance’s dedicated inventory, located at strategic and secure sites across the country, is stored away from potentially impacted sites. It is maintained to manufacturer’s standards, with pre-planned logistics that allow subscribers to confidently develop detailed plans for recovery following a significant grid outage.

Dedicated team to execute plans

Grid Assurance’s dedicated team of experienced professionals ensures all equipment is maintained, transportation plans are developed and approved, and performance drills are conducted to assure full execution capabilities at those times when execution is vital to grid restoration. The team is prepared to respond immediately to events and to provide dedicated assistance to subscribers throughout the deployment and delivery of assets.

Cost certainty & transparency

Utilities typically maintain some operational spares to replace equipment that fails due to normal wear and tear. However, it is undoubtedly more expensive for transmission owners and their customers to individually stockpile multiple, million-dollar pieces of equipment to prepare for full recovery following a high-impact event, which occur infrequently, compared to pooling their needs with other companies. By sharing inventory, Grid Assurance subscribers’ access to secure, firm inventory costs up to three to five times less than capitalizing additional operational spares on their own.

Regulatory clarity

A transparent, cost-based structure, modeled after typical FERC transmission tariffs, provides certainty and clarity for the cost of the equipment. FERC’s approval of the Grid Assurance Subscription Agreement also provides certainty of its prudency and cost recovery.

Known condition & warranty

Grid Assurance provides certainty that equipment will be available when needed for significant grid outages that may encompass multiple sites. Equipment is maintained according to equipment manufacturer’s recommendations and is checked by vendors. Maintenance records are kept, and all assets come with a fully transferable manufacturer warranty.

Promotes industry standardization

Grid Assurance develops a common specification for each equipment class that envelops the existing needs of subscribers and seeks to achieve greater ratings standardization. Since subscribers know the exact characteristics of the spare equipment, they can pre-plan how it performs on their system.

Risk analysis modeling tools to define needs

Grid Assurance has developed tools that help a subscriber determine their sparing needs for a multi-site event. These needs are calculated based upon probability of events and replenishment times. We developed a model to determine the inventory levels that Grid Assurance needs to maintain to achieve a 97-98 percent service level. These models help our subscribers understand their needs and provide an analytical basis for the inventory levels that Grid Assurance holds.

Analytical modeling tools to define needs for large scale events

Capital investment earns returns

Utilities are among the most capital-intensive industries. Utilities typically maintain some operational spares to replace equipment that fails due to normal wear and tear. In numerous cases it is economically prohibitive (for some utilities it may be as high as three to five times more expensive versus pooling assets1) for a utility to stockpile multiple spare assets, (often costing millions of dollars each), to prepare for full recovery from significant grid outages. Utilities’ access to capital funds is often constrained and prioritizing the use of these constrained funds is typically focused on grid projects that support growth and/or reliability necessary for their rate paying communities. It is difficult to allocate scarce capital funds for high-impact, low frequency events (extreme weather, cyber-attacks, physical attacks, etc.).


1 Factoring in elements such as Cost of Capital, Overhead Costs, Storage Charges, Inventory Charges, Insurance, IT Support, etc. can lead to annual inventory carrying costs as high as 15-20%. This equates to the “cost” of those materials doubling every five years. Given these spares may be held in inventory for 15 to 25 years, the cost of those assets increases 3 to 5 times over their life in inventory. Sharing “pooled” assets among numerous Grid Assurance subscribers reduces expenses per participant.

Event agnostic

Grid Assurance supports the broadest range of significant grid outage events including extreme weather events, physical attacks, cyberattacks, forest fires, earthquakes, geomagnetic disturbances, electromagnetic pulses and acts of war or terrorism.