Restoration of the electrical network: fast and reliable replacement of critical assets

The US electrical grid is our most critical energy infrastructure. But it faces growing threats and challenges that will affect its reliability and resilience.

A recent report from the US Department of Defense found that in addition to threats from physical and cybersecurity attacks and severe weather events, climate change may present a growing threat that can increase the frequency of damage to network assets. and make our nation vulnerable over time. .

Other factors that compound these ever-evolving threats are our reliance on foreign vendors as well as our aging network infrastructure. For example, extra high voltage (EHT) transformers, critical elements of transmission infrastructure, are often sourced from overseas and the existing asset base is aging faster than it is being replaced. And even more will be needed in the years to come, as the transmission network expands to accommodate new renewable energy generation.

Ensuring a safer future for the electricity grid

Utilities must strike the right balance to achieve resilience at optimal cost. To do this, they need to mitigate their risk. With respect to the threat of widespread damage to assets in multiple locations, this forces them to analyze their risks and develop an executable and effective plan to deal with them. These plans should ensure the certainty of immediate access and delivery of replacement equipment.

Of the alternative spare equipment programs available, most are only designed to partially meet the evolving requirements of fast, flexible, and certain network restoration.

The EEI Replacement Transformer Equipment Program (STEP) is a valuable form of mutual assistance between Investor-Owned (IOU) utilities that provides a process for acquiring an asset from another utility , but only in the event of a terrorist attack. In addition, STEP requires a presidential decree which, to date, has not yet been promulgated. Each participating utility is required to make available a limited number of assets (often only one) in such a case.

The EEI SPAREConnect program provides an additional complementary mechanism for owners and operators of IOU Bulk Power System assets to network with other SPAREConnect participants for the potential sharing of transmission and generation step-up transformers and other equipment. However, SpareConnect does not create or maintain a central spare equipment database. Therefore, a utility in need has no certainty as to whether what it needs exists, and if so, who has it, where it is, or its condition, their age or availability. The business in need has a responsibility to reach out to other participants, but there is no obligation for potential corporate donors to provide an asset.

The North American Transmission Forum’s (NATF) Regional Equipment Sharing for Transmission Outage Restoration (RESTORE) program is also a form of mutual assistance, designed to improve the resilience and reliability of the power grid by identifying sources and facilitating the replacement of equipment from the spare parts available. in participating companies following catastrophic events. This optional, self-funded program is available to NATF members at minimal additional cost. When a participant makes their need known, a committee chairs which one or more participants will provide reserve assets to meet the need. But again, specific equipment availability, quantity, quality, condition and warranty are not guaranteed.

Network restoration requires secure and fast access to critical transmission equipment

Network restoration after natural or man-made events affecting multiple network facilities at once can be a matter of life and death. Prolonged outages affect the most vulnerable in our society more than other populations and can lead to job loss, health problems and even death.

Fast food is essential. But extra-high-voltage transformers and other critical transmission equipment have extremely long lead times. This equipment is also difficult to transport, requiring even more time to be delivered or moved to where it is needed.

When an EHV transformer wears out or is damaged by external forces, the process of replacing it with another can be lengthy. Due to the redundancy of the design, a single transmission transformer failure will rarely cause customer outages. However, a more extreme event that damages multiple transformers in multiple locations can disrupt businesses and communities that depend on the grid for long periods of time. These extreme events are rare, but as mentioned earlier, the threat of such events has increased.

It is estimated that acquiring a new EHV transformer can take between 12 and 30 months and growing supply chain and materials issues are further lengthening this replacement time. The United States imports 85% of its EHV transformers and there is competition with other countries for limited production and raw materials such as special grade electrical steel. The high price of these transformers can range from 2.5 to 10 million dollars (including transport and installation). Finally, transformers are usually custom built, with long lead times for design, quote, manufacture and delivery; with components dependent on foreign production and supply chains.

Network resilience — a gap in equipment replacement planning

As EHV transformers have become more critical, their value has increased. And the delays in obtaining these assets have lengthened.

It is important that investor-owned utilities and other transmission companies have access to spare equipment, regardless of how a transformer or other critical piece of transmission equipment may fail or be damaged.

Utilities that supply their emergency equipment themselves usually keep a number of spares on the system. The number is usually determined based on operational failure rates and generally does not take into account widespread simultaneous failures of multiple facilities due to extreme events. Available spares are also usually stored or collocated at one of the working transformers’ site to minimize transportation time.

However, for extreme events such as physical attacks, severe weather or other natural disasters, these collocated spare parts would likely be damaged with the transformer in operation, so the spare part would become useless. Even if a utility is fortunate enough to have enough working spares in good condition to replace what has been destroyed, replenishing their spares inventory will typically require lead times of 12 to 18 months, but can now take up to 30 months. In the current supply chain environment, these longer lead times can be expected.

Subscribing to an industry-led solution that includes a secure, dedicated national inventory of pooled equipment, stored remotely from operating sites, can provide the right balance between maximizing certainty and speed. at optimal cost.

Grid Assurance is the industry’s only grid restoration solution with a fully functional, securely stored, guaranteed and maintained reserve of critical equipment, combined with pre-approved delivery logistics plans to help transportation companies restore power quickly and efficiently. Subscribers are entitled to immediate access to the number of spare parts they have subscribed to without restrictions, delays, or subject to committee approval or presidential decree. They also have prior knowledge and certainty of the specific performance and physical characteristics of the exact equipment they will receive. Their subscription allows them to purchase the transformers at the (known) original equipment price and with a manufacturer’s warranty that is transferable to them at the time of sale. Participation in other industry programs can add value as additional back-up resources, and their limitations are overcome by subscribing to the Grid Assurance model.

Utilities need an all-threat solution that restores power faster and helps protect against reputational risk. They need access to some secure national critical transmission inventory that is ready to deploy at any time.

David E. Rupert is Managing Director of Grid Assurance.