An aged 100 MWdc farm.

The interconnect approval queue decides who wins compute capacity — not GPUs. Undifferentiated 50 MW interconnect filings wait. You are not buying solar. You are buying an existing grid connection and filing a load the operator can say yes to. Texas (Pecos) is the worked example. Every grid has the same two hurdles: getting power out, and getting approval to draw power in after dark.

CFO: Economics
CTO: Cooling & generation
Counsel: Permitting

How the filing stays inside a permit you already have.

One way in

An aged 100 MWdc farm.

Fastest time to compute

Existing PV farm

Phase 0 is 50, Phase 1 is 58, then 153, then 175 MW

Buy or retask a 2012–2021 plant. Phase 1 is cooling only, about 35 acres of cassette rows and an air-cooled chiller. Phase 2 stays on the grid at 153 MW. Phase 3 is full off-grid at 175 MW. Inside the existing fence.

Same 100 MWdc site

Later phases grow firm IT on that farm

Phase 1 · 58 MW · 250 MWh tank

Phase 2 stays on the grid and reaches 153 MW. Phase 3 is full off-grid at 175 MW of firm IT. Same generation permit. Same interconnect.

Water: Closed loop. No cooling towers. No new evaporative right.
Noise and air: Rural night screen is about 55 dBA. Not a permit.
Envelope: Phase 1 is 58 MW. Phase 2 is 153 MW, still on the grid. Phase 3 is 175 MW, full off-grid.

Grid timeline — Texas is the named example

Phase 1 stays on the grid. Phase 3 leaves it.

The plant starts at 50 MW. Phase 1 is 58 MW, cooling only. Phase 2 is 153 MW and still on the grid. Phase 3 is 175 MW off the grid. Illustrative. Not a permit.

If the grid operator…	The site	Grid MW	Time
Phase 1, cooling only	Grid-tied. Cassette rows and an air-cooled chiller. No engines.	58 MW	First hall
Phase 2, grid + engines	Still interconnected. Engines and the heat train are on.	153 MW	About 1.87 years vs Phase 1
Phase 3, full off-grid	No import. On the same site. Engines carry the supply.	175 MW	2.22 years vs Phase 1
The alternative is a greenfield hall	A new line, not this site.	New request	Years if transmission is new

Texas figures. The 50 MW hall stays under that market’s large-load threshold where one exists. Growth past 50 MW on this page is the planning screen.

Permitting and economics per additional MW of AI

Capex, water, noise, air, and time are the same decision. Cooling-first reuses a permitted interconnect and keeps a smaller chiller, not a chiller for the whole duty. Time is to additional IT, not to a greenfield campus.

Path	$M / MW	Fuel exposure	Gen. water	Cooling water	Time	Emissions / noise
Same·Point cooling-first	$0.72–0.78M	Low	None added	Low	6–12 mo	Low
Reciprocating gas engines	$1.5–2.2M	Medium	Medium–high	Mechanical cooling	12–24 mo	Medium
Same·Point full platform	$3.2M	Low	None added	Low	Staged	Low
Aeroderivative simple-cycle GT	$3.2–4.6M	High	High	Mechanical cooling	24–36 mo+	High
Fuel cells	$7–8M	High	Low	Hall cooling extra	90 d–18 mo	CO₂ 680–830 lb/MWh

Reciprocating engines are typically more efficient than simple-cycle aeroderivative turbines. Combined-cycle GTs are not in this table. Fuel-cell generation-side water is low in normal operation. Same·Point rows are per MW of firm IT. Engine, turbine, and fuel-cell rows are per MW of generation. Fuel cells are about $7–8M per MW installed (2026). That price does not include IT cooling.

Why the overlay beats a new plant

Reuses the interconnect and land you already have
About 35 acres of radiator rows, plus a smaller chiller, reject 50.7 MWth for the 50 MW hall
The chiller nameplate is 8.45 MWe at COP 6. On the hottest hour it supplies 2.1 MWth of the 50.7.

Request the briefing pack

Example cover letter

A load the operator can say yes to.

Illustrative letter. Names are fictional. The hall is 50 MW of computing load at an existing solar interconnection, under the 75 MW large-load threshold.

Sierra Mesa Computing, LLC

Grid and Energy

2200 Post Oak Boulevard, Suite 1400
Houston, Texas 77056

28 August 2026

Interconnecting Transmission Service Provider
Copy: Director, Resource Integration
Copy: Director, System Planning
Electric Reliability Council of Texas, Inc.
8000 Metropolis Drive, Building E, Suite 100
Austin, Texas 78744

Copy: Qualified Scheduling Entity for Sierra Mesa Computing

Re: Co-located computing load under 75 MW — Mesa Flats Solar, Pecos County, Texas.
Load Information Form and request for TSP coordination.

Dear Sir or Madam:

Sierra Mesa Computing, LLC requests interconnection of 50 MW of computing load co-located with Mesa Flats Solar, an existing Generation Resource in Pecos County. Peak demand at the point of interconnection stays under 75 MW, including site auxiliary. Enclosed is the Load Information Form for co-located load under 75 MW, for coordination by the interconnecting TSP and ERCOT.

This is a differentiated load addition at an existing generation interconnection. The plant is already in service. The hall uses power the array is already producing. Peak import remains below ERCOT’s 75 MW Large Load threshold. The load will be registered as a Controllable Load Resource.

Interconnection: Existing, energized generation POI. Co-located with the solar resource and battery already at the site. No new transmission line and no new generation interconnection.
Peak demand: 50 MW of contracted computing load, plus site auxiliary. Below the 75 MW Large Load threshold.
Day / night: During solar hours the hall is served from the existing array; net interchange at the POI falls. Overnight import is the 50 MW hall.
Water: Closed-loop, air- and ground-coupled cooling. Negligible makeup. No evaporative towers. No community potable water for cooling. No new water right.
Noise: Heat rejection is distributed across the existing tracker field. No new cooling-tower cell and no new chiller yard. Operating sound is pumps and a dry-cooler fail-safe, in keeping with the solar plant already there.
Emissions: Grid-tied operation uses no on-site combustion. Islanding is an option if overnight service is late. It is not required to energize the load.
Load reduction: The load will respond to ERCOT instruction as a Controllable Load Resource, including curtailment and ramping consistent with Protocols for loads 25 MW or greater. The battery at the POI will be offered through our QSE for ancillary services ERCOT already procures.
Islanding: The electrical and thermal design allows the 50 MW hall to run islanded if firm overnight service is not available on the customer’s schedule. Islanding is an option. It is not required to energize the load.

We request that the interconnecting TSP coordinate this addition as co-located load under 75 MW, identify any studies required before energization, and confirm the path with ERCOT Resource Integration. We will provide the load model applicable to facilities 25 MW or greater, and any water, cooling, and community-impact information the Commission or ERCOT requests of computational load.

We are prepared to brief the TSP and ERCOT on the net-interchange profile, controllable-load capability, and the closed-loop cooling design.

Respectfully submitted,

Alexandra V. Chen

Vice President, Grid and Energy

Sierra Mesa Computing, LLC

Enclosure: Load Information Form — co-located load under 75 MW
cc: Qualified Scheduling Entity

Modeled on ERCOT’s Load Information Form for co-located load under 75 MW. The interconnecting TSP files with ERCOT. Names are fictional.