Field notes The Energy Transition for the Rest of Us

Catalyst N° 066 of 125 12 Jun 2025

The state of play of data center development

with Chris Sharp, chief technology officer, Digital Realty

In this note
  1. 01The question
  2. 02The answer
  3. 03The argument
  4. 04What you need to know first
  5. 05Details worth keeping
  6. 06Claims worth citing
  7. 07Where it’s contested

The question

Is the AI buildout spreading data centers out to wherever cheap power happens to be, or concentrating them further into the regions that are already full?

The answer

Concentrating them. Training frontier models did push some geographic spread, but Sharp sees that leveling out, and the growth he expects from here is inference, which wants to sit inside existing cloud regions and close to the data it runs on. Chasing stranded power works for a narrow class of workloads and is shrinking as a share of the market, which means the power constraint keeps binding in exactly the places that are hardest to build.

03The argument

Sharp starts from the workload, because the workload dictates what infrastructure a site needs. Training a frontier model is the part that can travel: you feed it one large fixed data set, so the site mostly needs power, land, labor and water. That did force broader regional deployment, and he thinks that wave is leveling out. Inference is what he sees driving region-specific growth from here, and it lands inside the existing cloud availability zones, the clusters near major city centers built to hold uptime and performance commitments for enterprise customers. Kann offers the standard lay version of this, training anywhere and inference near users because latency matters, and then the more interesting speculation on top of it: split inference into latency-sensitive and latency-insensitive halves, and send the insensitive half out to cheap, clean, possibly intermittent power in the middle of nowhere.

Sharp grants that this works, then explains why it is the shrinking half. Latency is not really the binding property, because as long as latency is consistent most workloads tolerate it. Throughput is the constraint, meaning the sheer volume of data that has to move. Simple text-to-text inference can serve all of North America from two or three markets, but he calls that an early-innings picture. More advanced reasoning models do not generate one token against one prompt and stop; a token may pass through several models to check for hallucination or to route through a mixture of experts, so AI infrastructure increasingly wants to be near other AI infrastructure. Real-time inference also wants to be near the data it learns from, which sits in the tier-one markets. Chip economics push the same way, since GPUs are expensive and training is spiky, so operators want to backfill an installation with inference to raise utilization and return on invested capital. Kann’s summary, which Sharp endorses, is that going where the power is retains real validity while the relative share of what can be built that way dries up.

The consequence is that the constraint binds where it hurts most. Northern Virginia is a multi-gigawatt market at roughly 0.5% vacancy, and Sharp is careful about what is actually short there: not necessarily generation, but distribution. Concept to delivery for a versatile data center runs about 24 months, some interconnections now run longer than that, and utilities are asking for four-year forward load projections. Transformer lead times are past 50 weeks and gas turbines are backlogged beyond 2029. His two answers are unglamorous. One is vendor-managed inventory, buying switchgear and long-lead equipment ahead of need. The more important one is master planning with the utility over five years or more, which he frames as a mutual credit test: a utility will not overbuild unless it believes the load will show up and stay, so the developer’s job is to bring creditworthy customers who intend to occupy the asset for ten years or more, and then actually take the power down when it said it would.

Two intuitions get overturned along the way. If inference arrives in five-megawatt chunks, why not build a scatter of 120-megawatt sites, each easier to interconnect than one two-gigawatt campus? Sharp says customers really do think in five-megawatt blocks but want them contiguous, plugged into a single hundred-megawatt hall for operations and resiliency; the customer indifferent to location is the outlier. And like the grid, you have to size for the peak. The second is the long-standing hope that some workloads could skip backup power and be sited anywhere. Sharp wanted to build that facility and never saw one come to market with an acceptable service-level agreement, and liquid cooling has made it worse rather than better, because the heat does not displace itself and a stopped pump ruins the chips. Bridge power lands the same way. Running a data center off site generators until the interconnection arrives is an outlier; the common version is a negotiated deal with the utility, bringing your own generation or batteries under something like an interruptible tariff in exchange for faster power. His reason is strategic rather than technical. Becoming a generator is a short-term gap nobody would attempt absent the constraint, and he would rather invest in the utility doing the thing it is already good at.

04What you need to know first

Training and inference
Training builds the model once against a large fixed data set. Inference is running the finished model to answer requests, continuously. Almost every siting argument here turns on that split.
Availability zone
A cluster of cloud capacity in a region carrying a specific uptime and performance promise. They sit near major city centers and do not exist in most smaller markets.
Throughput versus latency
Latency is delay; throughput is how much data moves per unit time. Sharp’s point is that consistent latency is usually tolerable while throughput is what actually pins a workload to a location.
Bridge power
On-site generation covering the gap between when a data center wants to run and when its grid connection arrives.

05Details worth keeping

  • The cold open is Sharp joking about “bragawatts,” the noise of everyone claiming a gigawatt. His serious version: the power, and even the financing, required to meet the upper-end projections does not exist.
  • He predicts failures that will get written about, from customers who secured a total capacity block but could not support the power density inside it, or who built for a spike whose long-run utilization came in far below projection.
  • Demand is not uniformly for the largest possible building. Some customers want a contiguous hundred-megawatt GPU array, inference comes in roughly five-megawatt blocks, and private AI deployments can be a couple of megawatts embedded in a customer’s existing footprint.
  • Digital Realty operates almost three gigawatts of diesel generation today, some of it used for peak shaving as well as backup.
  • Sharp frames AI as an “and” rather than an “or” to cloud, embedded into services people already buy rather than replacing them.
  • Liquid cooling is his efficiency story and his reliability problem at once: liquid is 800 times denser than air, which improves efficiency, and it is also why he wants roughly three nines of reliability on the cooling loop.
  • His closing example is Gefion in Copenhagen, one of the largest DGX pods, built for Novo Nordisk’s pharmaceutical work.

06Claims worth citing

All figures as stated on 2025-06-12 and attributed to the speaker, not verified independently. Lead times, backlogs and vacancy rates move fast.

  • Northern Virginia has about a 0.5% vacancy rate in a multi-gigawatt market. Sharp
  • All else equal, about 24 months from concept to delivery for a versatile data center; some interconnections now run longer than that. Sharp
  • Utilities are requesting roughly four-year-ahead load projections. Sharp
  • Transformer lead times are 50-plus weeks. Sharp
  • Gas turbines are backlogged beyond 2029. Sharp
  • Digital Realty operates almost three gigawatts of diesel generators. Sharp
  • Liquid is 800 times denser than air. Sharp
  • He describes a gigawatt-scale master-planned build near Dulles airport, and separately a 500-megawatt example of projecting load and then taking it down. Sharp
  • On liquid-cooled builds he says billions and billions of dollars for a 30 to 35 megawatt build scaling up to 50 megawatts. The sentence runs cost and capacity together, so what the billions are counting is not clear. Sharp
  • Company and career context: Digital Realty around 20 years old, Sharp 10 years there and 15-plus years in the sector. Sharp

07Where it’s contested

  • Whether flexible workloads migrate to stranded power. Sharp says the approach is viable and then argues its share shrinks. He does not say it disappears, and nothing in the episode settles the question either way. It is also worth noting he runs technology for a colocation developer whose footprint sits in the tier-one markets his argument favors.
  • How much of the pipeline is real. Kann frames it as two things being true at once: genuine explosive demand for compute, alongside a volume of load interconnection requests an order of magnitude larger than what will get built. Sharp agrees, says on record that Digital Realty works to avoid being aligned to a bubble, and separately says he only sees demand increasing. He puts no number on how much of the pipeline is noise.
  • The workload-flexibility hope is dismissed from experience, not analysis. He says he was hopeful, never saw one built with the right service-level agreement, and concedes some individual components could carry less resiliency. That is weaker than saying it cannot be done.
  • Tapped out is scoped, not universal. He says power has been tapped out in a lot of these markets, and in Northern Virginia specifically identifies distribution rather than generation as the shortfall. Both qualifiers are easy to drop, and the meaning changes if you do.
  • Customer specifics are off limits. He declines to describe workloads he is building for particular customers and reasons instead from public announcements, so even the person building the buildings is partly inferring the workload picture from the outside.

Cite as: “The state of play of data center development,” The Energy Transition for the Rest of Us, note on Catalyst with Shayle Kann, June 12, 2025. CC BY 4.0. View the Markdown