If you're currently trying to procure a 110kV power transformer for a substation, a data center campus, or a renewable energy interconnection, you already know the number that's keeping project managers up at night in 2026: standard power transformers are averaging 128 weeks of delivery, generator step-up units have crossed 160 weeks, and analysts at PwC now quote up to four years for some high-capacity units.

Roughly 80% of large power transformers used in the U.S. are imported, and the situation is similar across much of Europe and parts of Asia, where the same constrained supplier base is simultaneously serving grid modernization programs, AI data center buildouts, and electrification of industrial processes.

As engineers who design and manufacture power transformers for export, we want to walk through what's actually driving this shortage, what a 110kV oil-immersed power transformer needs to deliver technically at this voltage class, and why diversifying to a second, qualified manufacturing source has become a legitimate risk-management strategy for project timelines in 2026 — not just a cost play.

Why the 110kV transformer market is under so much pressure in 2026

Three demand curves are colliding at once, and all of them pull on the same pool of grain-oriented electrical steel and skilled winding capacity:

1. AI data center buildout. U.S. data center capacity is projected to reach 110 gigawatts by 2030, up from roughly 24 GW today — consuming, over that period, about eight times as much electricity as electric vehicles are expected to. Data centers' share of the electrical equipment market could grow from under 2% in 2020 to as much as 40% under accelerated scenarios.
2. Structural material bottlenecks. Transformer cores depend on grain-oriented electrical steel, a highly specialized material. In the United States, a single domestic producer supplies it, which means every manufacturer drawing on that material competes for the same limited output — a bottleneck that shows up directly in quoted lead times.
3. Compounding demand growth. Generator step-up transformer demand has grown 274% since 2019, substation transformer demand is up 116%, and overall power transformer demand has grown 119% over the same period — while manufacturing capacity has expanded far more slowly.

The practical result: transformer procurement now happens before design development is finished, not after, because equipment availability — not capital or permitting — has become the primary constraint on project timelines for utilities, data center developers, and industrial users alike.

What is a 110kV oil-immersed power transformer?

A 110kV oil-immersed power transformer is a high-voltage transmission-class transformer used to step voltage up or down between transmission networks (typically 110kV) and sub-transmission or industrial distribution levels. Unlike smaller distribution transformers, this class of equipment is defined by:

• Large capacity ratings, commonly from a few MVA up to tens of MVA depending on application;
• Oil-immersed cooling and insulation, providing efficient heat dissipation and the overload capacity required for continuous operation at power plants, industrial substations, and utility interconnection points;
• Compliance with international standards such as IEC 60076, including no-load, load, temperature-rise, lightning-impulse, and partial-discharge testing before shipment.

You can review the full specification range, including 110kV and higher-voltage models, on the 66kV and above series page, which covers configurations designed for power plants, substations, and industrial enterprises.

Why a second qualified manufacturer matters more than ever in 2026

To be clear: switching manufacturers mid-project isn't a decision engineers make lightly, and it shouldn't be treated as a simple swap. But three factors are pushing procurement teams to actively qualify additional sources in 2026:

• Domestic capacity is fully booked years out. Even with nearly $1.8 billion in announced North American manufacturing expansions, industry analysts still expect the pad-mount and mid-size transformer shortage to worsen before it improves, driven by data centers, manufacturing facilities, and EV charging infrastructure competing for the same production slots.
• New large power transformer plants won't reach production until 2027 or later. Several announced domestic expansions are targeting a 2027 production start, which does nothing for a project that needs equipment in 2026.
• Utility-scale renewable projects risk becoming stranded assets if transformers can't be secured in time — a risk that applies just as much to solar and wind interconnection projects as to data center campuses.

This is precisely where establishing a relationship with an experienced overseas manufacturer — one with its own production line, its own testing protocols, and a track record of international delivery — becomes a practical hedge rather than a last resort. AISITE, for example, has delivered oil-immersed transformers ranging from 3,000kVA to 12MVA for solar PV projects across Southeast Asia in the past year alone, alongside ongoing exports to the Middle East, Africa, and Latin America.

Technical criteria to check before qualifying a 110kV transformer supplier

1. Standards compliance and factory testing

Confirm the manufacturer performs the full IEC 60076 test suite — no-load loss, load loss, temperature rise, lightning impulse, and partial discharge — and can provide test reports before shipment, not just after. These reports are typically available in the qualification and certification section of a reputable supplier's site.

2. Winding and insulation design

For high-voltage, high-capacity units, look for a magnetic core built from laminated grain-oriented silicon steel and windings insulated with materials rated for harsh industrial atmospheres and short-circuit stress — the same design principles that apply across AISITE's 35kV and above series and higher-voltage transformers.

3. Customization capability

Every substation has a slightly different combination of voltage ratio, vector group, cooling method, and climate requirement. A manufacturer offering a genuine customized transformer program — rather than only catalog units — reduces the risk of costly redesigns later in the project.

4. Track record with your application type

If your project is a solar or wind interconnection, ask specifically about experience with generator step-up transformers designed for harmonic loads and fluctuating generation profiles, as detailed on the New Energy Transformer page.

5. Logistics and delivery track record

Ask for recent, verifiable delivery examples — port arrival dates, project names, and shipment documentation — rather than only nameplate capacity claims.

110kV transformer vs. lower-voltage alternatives: choosing the right class

If your project doesn't require transmission-level interconnection, it may be more efficient — and faster to procure — to specify a 35kV and above series transformer or a 10kV transformer instead, depending on where your load actually sits in the network.

Real-world applications driving 110kV transformer demand in 2026

• Hyperscale data center campuses, where grid interconnection and on-site power infrastructure are now front-end feasibility inputs rather than late-stage procurement items — relevant across state grid interconnection solutions.
• Utility-scale solar and wind farms, where the transformer functions as the step-up unit between generation and the transmission network — see photovoltaic power generation solutions.
• Battery energy storage systems (BESS) integrated at the substation level, an area where safety engineering — including thermal runaway protection — is increasingly scrutinized; see energy storage solutions.
• Heavy industrial and metal smelting operations, which require high-capacity, high-reliability transformers capable of sustained peak loads — covered under metal melting solutions.

For projects that need a complete package — transformer plus high- and low-voltage switchgear in an integrated enclosure — it's worth reviewing HV LV switchgear options alongside the transformer itself, since coordinating both from a single manufacturer reduces interface risk.

Frequently asked questions about 110kV power transformers