Data centers and new power in San Mateo County, CA
250 MW of new power is waiting to connect to the grid in San Mateo County, CA — 1 active requests. Typical wait: 5.5 years. 1 projects are built, 10 withdrawn. Data as of 14 October 2026.
Is one near your house?
We have not mapped a large AI data center inside San Mateo County itself — but we track the biggest ones nationally, and requests to connect new power here are on the public record.
What is happening with electricity in San Mateo County
Every new power plant, battery or big customer has to join a waiting list before it can plug into the grid. This is what that list looks like in San Mateo County right now.
Where every request ever filed here ended up
Most requests in the US are withdrawn — a developer tests a site and moves on. That is normal, not a warning sign for San Mateo County.
What kind of power is asking to connect
By capacity requested. Data as of 14 October 2026.
All the numbers
12 requests ever filed
Source: interconnection queues published by CAISO. Parsed and normalised by Watt Street. Data as of 14 October 2026. A queued project is a request, not a commitment.
Outcome of every request filed here
| Outcome | Projects | Capacity | Share |
|---|---|---|---|
| Built | 1 | 13 MW | 8.3% |
| Still waiting | 1 | 250 MW | 8.3% |
| Withdrawn | 10 | 958 MW | 83.3% |
| Paused | 0 | — | 0.0% |
Waiting to connect, by type of power
| Type | Projects | Capacity requested |
|---|---|---|
| Batteries | 1 | 250 MW |
Key dates for projects here
1 dated · next closes 2026-10-15 (CAISO)
| Queue | What closes | Closes | Standing |
|---|---|---|---|
| CAISO | CAISO Cluster 16 interconnection request window Interconnection requests submitted through the GRIP portal. | 2026-10-15 | confirmed source |
| FERC | FERC large-load show cause — stakeholder comments on RTO responses Comments on the six RTO/ISO responses to the FPA section 206 show-cause orders of 18 June 2026 (PJM EL26-67, SPP EL26-68, NYISO EL26-69, MISO EL26-70… | No date published yet | unconfirmed source |
| FERC | FERC RM26-4 — generic large-load rulemaking Still at ANOPR stage. | No date published yet | confirmed source |
| FERC | Georgia PSC - Georgia Power must file large-load contracts 30 days before execution A standing obligation rather than a dated one: large-load contracts must be filed with the commission at least 30 days before they are executed. | No date published yet | confirmed source |
A date marked confirmed was checked by a person against the authority's own tariff, order or form page. Anything else is listed so you know it exists, with a link so you can check it yourself. Full calendar.
The biggest projects on file
top 12 by size
| Project | Type | Capacity | Status | Filed | Queue |
|---|---|---|---|---|---|
| Withdrawn project | Batteries | 412 MW | withdrawn | 2015-04 | CAISO |
| BAYLANDS BATTERY | Batteries | 250 MW | active | 2021-04 | CAISO |
| Withdrawn project | Batteries | 250 MW | withdrawn | 2020-04 | CAISO |
| Withdrawn project | Batteries | 65 MW | withdrawn | 2021-04 | CAISO |
| Withdrawn project | Batteries | 50 MW | withdrawn | 2014-04 | CAISO |
| Withdrawn project | Batteries | 41 MW | withdrawn | 2021-04 | CAISO |
| Withdrawn project | Batteries | 40 MW | withdrawn | 2018-04 | CAISO |
| Withdrawn project | Batteries | 40 MW | withdrawn | 2021-04 | CAISO |
| Withdrawn project | Batteries | 20 MW | withdrawn | 2016-05 | CAISO |
| Withdrawn project | Batteries | 20 MW | withdrawn | 2015-04 | CAISO |
| Withdrawn project | Batteries | 20 MW | withdrawn | 2017-05 | CAISO |
| OX MOUNTAIN LANDFILL GAS GENERATION | Not stated | 13 MW | completed | 2005-06 | CAISO |
How San Mateo County compares
#842 in the US · #26 in CA
San Mateo County ranks #842 of 1,607 US counties by power waiting to connect, and #26 of 42 in California.
| County | Waiting | Capacity queued |
|---|---|---|
| Los Angeles County | 32 | 14.7 GW |
| Kern County | 51 | 13.8 GW |
| Riverside County | 22 | 7.8 GW |
| San Bernardino County | 19 | 7.3 GW |
| Fresno County | 28 | 6.5 GW |
| Imperial County | 34 | 6.4 GW |
| Sacramento County | 16 | 3.6 GW |
| Kings County | 8 | 2.5 GW |
Common questions about power in San Mateo County
How long does it take to get power for a data center in San Mateo County, CA?
The median wait for a project still in the interconnection queue in San Mateo County is 5.5 years. Across the US, most large loads are quoted three to seven years depending on the market and whether network upgrades are needed. 1 projects in San Mateo County have reached energization and 10 were withdrawn, so the withdrawal rate here is a better guide to risk than any single quoted timeline.
How much capacity is available in San Mateo County, CA?
250 MW is currently requested across 1 active interconnection requests, and 13 MW has actually been built. A queued megawatt is a request, not deliverable capacity — most queued projects are never built. For deliverable offtake capacity at a specific substation you need a utility study, not a queue.
Is San Mateo County, CA a good site for a data center?
This page gives you the power half of that answer: what is queued, what has been energized, how long the wait runs, and which large load interconnection requests are already recorded nearby. The other half — the state policy position, moratoriums and large load tariffs — is on our California policy page.
Where does the data on this page come from?
The interconnection queue published by the transmission providers serving San Mateo County — CAISO — parsed and normalised by Watt Street. Every figure carries the date it was true. Data as of 14 October 2026.
Go deeper on San Mateo County
The interactive map plots every one of these applications, and a generated county report puts them in a sourced PDF with the date each figure was true on every page.
Open San Mateo County on the map County reports All of California