PGIQ Rating v2 (reliability-adjusted) · as of June 2026

🇺🇸 CAISO (California)

Viable, with conditions, and access is getting harder● Under review Reliability flags found
Tier 3 Workable · Composite 49/100, #49 of 79 markets (fundamentals 56 minus a reliability dock) · Outlook Negative · High confidence · how we score

A huge, proven ecosystem (Silicon Valley), but for a new large load it is expensive, supply-tight into the evening ramp, and queue-constrained. Momentum keeps it from falling further; access and cost keep it out of Tier 2.

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One market,
four reads

BuildTier 3Siting rating SellGrade BOfftake PlanRisingLoad pressure MonitorWatchGrid strength

The same market, four decisions. Open any lens to see this market ranked against the rest.

Time to energize · file to power

~60 mo

File a large load today, powered ~2031. Typical range 51 to 69 months, measured.

End-to-end wait for a large new load, from a complete application being accepted to full firm energization of the nominated MW. Earlier milestones (initial, phased, temporary or conditional energization) are reported separately. A typical case, not a firm quote. · Source: LBNL Queued Up 2026 · Compare markets →

The same market, read four ways

BuildSellPlanMonitor

CAISO (California) is a moderate market to sell power into

Grade B (Moderate)

Offtake score 70/100

Demand 54, build feasibility 45, combined into the score. For a seller: where buyers already pay, how tight supply is, and how feasible new build is here.

Price to beat

A 100 MW load on our standard case pays about $120/MWh delivered here. A competitive supply offer works against that level.

Queue depth (generation and storage)

About 191 GW in the interconnection queue (the line to connect to the grid), typical wait 60 months.

Regulatory momentum

Mixed, stable. FERC's 18 June 2026 Section 206 show-cause order directs CAISO to justify or rewrite its large-load and co-location tariff terms, so the rules for connecting a data centre are formally in flux; California's high retail costs and its own cost-allocation review add friction on top.

See it on the Offtake Grade →

CAISO (California): little room at system level, rising demand pressure

Little room 34/100

System-level room, not local capacity

Local capacity: not assessed. We have found no operator publication of area or substation capacity for this market, so whether the bus serving a candidate site can take the load is an open question. Absence of a finding here is not evidence that capacity exists.

Two reads for a grid planner: how much room the system as a whole looks to have (Little room), and how hard demand is already pushing (Rising). The first is a market-level estimate from connection ease, forward adequacy and reliability margin. It is not local deliverability. Capacity at a specific substation is not assessed for this market, and a market can look roomy while the bus you want has nothing available. Confirm local capacity with the utility before relying on it.

Generation and storage queue

191 GW requested; about 38.2 GW likely to reach operation after historical withdrawal. The gap is speculative pipeline. This counts generation and storage seeking to connect, not load.

Demand growth

Fast load growth in our read, the pull on your system.

Future firm supply

Future firm supply: adequacy flagged for a large new load.

Load Pipeline Reality → Where demand is hungry → Connection friction →

Grid Risk Annex BETA

Watch

Needs structuring or mitigants · grid strength 52/100

A cited, dated grid-risk read on CAISO (California) for a capital provider, the banks and private-credit lenders, infrastructure funds and insurers holding or underwriting a power or data-centre exposure here. Drop it into a credit memo and watch each factor over the life of the exposure.

Read it against your asset. For a load asset (Buy), weight connection access and energization timing. For a generation or offtake asset (Sell), weight offtake demand, curtailment (when a plant is told to stop feeding the grid) and cost realisation. For a grid or transmission asset (Move), weight load-pipeline reality and buildout risk.

Rating and track record

PGIQ Tier 3 Workable, outlook Negative, High confidence. Scored on a public, dated, falsifiable record you can cite in a credit memo.

Delivery reliability

Reliability flags found in the bulk and local outage record we reviewed.

Future firm supply

Future firm supply: adequacy flagged.

Cost certainty

Recurring cost about $120/MWh (band $95 to $155) for the standard 100 MW case, basis triangulated. Excludes connection capital.

Regulatory / stroke-of-pen

Execution risk

191 GW in the generation and storage queue, about 80% historically withdrawn, the risk the project or load actually energizes on time.

Ongoing monitor

Track this market's rating actions and the Global Power Index as a covenant-style monitor over the life of the exposure.

Monitoring plan

Covenant-style triggers to watch over the life of the exposure: a change in the PGIQ rating or outlook; a dated regulatory move (stroke-of-pen risk); a capacity-auction or cost-band shift; a forward firm-supply adequacy warning; and a rise in queue drop-out or connection friction. Track them on this market page and the Global Power Index, or as Analyst Desk alerts.

Sources: CAISO battery report

This is a directional grid-risk screen, not a credit rating, and not investment, engineering or procurement advice.

The formatted, cited Grid Risk Annex export is an Analyst Desk feature.See the Grid Exposure Monitor →

Regulatory momentum

The regulatory and permitting environment is increasingly the binding variable for a new large load.

Mixed→ stable

Why: FERC's 18 June 2026 Section 206 show-cause order directs CAISO to justify or rewrite its large-load and co-location tariff terms, so the rules for connecting a data centre are formally in flux; California's high retail costs and its own cost-allocation review add friction on top.

What would change the read: The Section 206 process settling on clear large-load connection and cost-allocation rules, and California resolving who pays for the supporting build.

The five pillars behind the tier

The pillar signature: Access, Availability, Cost, Momentum, Carbon, taller is stronger. The same shape repeats across every market so peers compare at a glance.

Access30%45

Constrained access: deep cluster-study queue, storage-heavy backlog.

Availability25%48

Tight availability: the evening net-load ramp as solar fades.

Cost25%68

High cost.

Momentum15%70

High momentum: the established Silicon Valley cluster.

Carbon5%68

Carbon moderate (~230 g), solar-and-gas with heavy storage.

Default weights, which lean toward cost and access rather than carbon: Access 30 · Availability 25 · Cost 25 · Momentum 15 · Carbon 5. Momentum reflects the data-center build already underway, not just stated intentions.

Seller view: Read these the other way: momentum is your customer pipeline, cost is your revenue ceiling, and access is how hard it is to build and sell here, not only to connect.

Reliability overlay

Reliability adjustment: the five-pillar score of 56 is reduced to 49, a deduction of 7 points, reflecting the delivery-reliability and firm-supply risks flagged below. Reliability is reported as five separate layers, never as one combined label, because they answer different questions and a strong answer on one does not cover a gap in another: what has actually failed on the bulk system, what a forward assessment expects of firm supply, how the local network performs, what your contract actually promises, and what your site is designed to ride through. Any one of them can cap the tier.

Historical bulk-system performance: Reliability flags found

ISO-ordered rotating outages during the August 2020 heat wave (about 492,000 customers cut on Aug 14) show supply-shortfall load-shedding risk at peak.

What this means: A large new load should expect genuine exposure to forced power cuts (curtailment), price spikes, and delays in getting connected, and should design in backup power or firm supply contracts.

event-based · CAISO rotating outages fact sheet

Historical utility-territory delivery performance: Reliability flags found

Average customer interruption (SAIDI) of 177.14 minutes per year in 2024, excluding major event days as filed. Public Safety Power Shutoffs: utilities proactively de-energize lines during wildfire-risk weather, so a load can lose grid power for reasons unrelated to its own site.

event-based · CPUC Public Safety Power Shutoffs · EIA Form 861, Schedules 3B and 3C (annual electric power industry report) (IEEE 1366 major-event treatment, customer-weighted blend of 3 utilities, regional context only)

Role not yet declared. We have not recorded whether this is one operator’s filing or an average across several, so read it as context until we do. major event days identified by IEEE 1366 (2.5-beta method). It is a territory-wide history and is silent on: performance at a specific substation or feeder; transmission-level service, which is a different product from distribution service; the industrial or large-load customer class specifically; N-1 or other redundancy architecture at the supplying substation; contractual curtailment rights the utility may hold over the load; power quality and momentary interruptions, which this metric excludes by construction; on-site UPS, storage or generation; forward adequacy: it is a record of what happened, not a forecast.

Which utility would serve you?

The market figure above is an average across these territories. Your site sits in one of them, not in the average. Each row below is that utility’s own filed record, which is the evidence a Project Case can actually rest on.

Serving utility	SAIDI min/yr	Customers	Major-event method
Pacific Gas & Electric Co. (CA)	275.6	5,795,693	IEEE 1366
Southern California Edison Co (CA)	100.25	5,316,264	IEEE 1366
San Diego Gas & Electric Co (CA)	71.13	1,527,274	IEEE 1366

Filed to EIA Form 861 for 2024, excluding major event days. Territory-wide averages: see the layer note above for what they do not establish.

Forward resource adequacy (assessed): Adequacy flagged

NERC's 2024 assessment rates California elevated-risk, with extreme heat likely to cause reserve shortfalls.

What this means: A large new load faces occasional exposure here. Monitor conditions and keep a contingency plan.

assessed · NERC 2024 Long-Term Reliability Assessment

Contractual service terms: not assessed

We have not compiled what firm service actually promises here: whether it is firm, non-firm or interruptible, the conditions under which you can be curtailed, the redundancy required of you, and the transfer time behind any N-1 commitment. Treat this as an open diligence item, not as an indication that service is firm.

Ask the utility for the tariff or service agreement terms before relying on firm supply.

Designed site resilience: not applicable at market level

Utility feeds, UPS, storage, on-site generation, islanding, black start and the residual energy you still expect to lose are properties of a specific site design, not of a market. This layer only exists once there is a site, and we never assert it for you.

Confidence: High. Each input is labelled as measured, modelled, or drawn from a specific event, and is framed as a risk to a prospective large new load, not as a verdict on any utility or grid operator. Forward adequacy is an assessment of what is expected, not a measurement of what has happened; it is a forecast and is labelled as one.

Seller view: Tight forward capacity (firm supply promised for future years) is scarcity that firm generation and storage get paid for; an adequacy flag is a demand signal for new supply, not only a risk to a load.

Supply relief outlook

Will the power crunch ease before your load energizes? This nets the demand racing for capacity against the new supply likely to arrive and the old supply leaving. A cross-side read, using the same data a seller sees the other way.

Balanced

Demand pressure

Fast load growth competing for the same capacity.

New supply in motion

About 38.2 GW of the generation and storage queue is likely to reach operation after historical withdrawal.

Can new supply arrive

Regulatory momentum mixed, stable.

Future firm supply

Future firm supply: adequacy flagged.

What this means: Supply and demand look broadly balanced; the outcome hinges on the drivers below.

Reliability metrics

Delivery reliability (measured)

The average customer loses about 177.14 minutes of power per year (2024). This is the standard regulator outage measure (SAIDI); lower means a more reliable grid.

Source: EIA Form 861, Schedules 3B and 3C (annual electric power industry report) (IEEE 1366 major-event treatment, customer-weighted blend of 3 utilities, regional context only)

Hard, cited measures behind the reliability overlay above: the regulator outage series (SAIDI, measured, published with a lag) and the forward resource-adequacy assessment (a measured forecast). Framed as risk to a prospective large new load, not a verdict on any utility.

Interconnection queue

These are generation and storage interconnection queues. They show how congested the interconnection system is. They do not measure how long a new large load waits, and their withdrawal rates are not load withdrawal rates. At the end of 2025, generation and storage projects totalling about 2,060 GW were actively waiting in United States queues, down 10% from a year earlier. Of the capacity that entered between 2000 and 2020, about 75% withdrew before connecting and only about 13% reached operation by end-2025. The typical project built in 2025 waited about 61 months from request to operation (Lawrence Berkeley National Laboratory, Queued Up 2026). Figures below are refreshed quarterly; each is labelled measured or modelled.

Active queue depth

191 GW

Typical wait

60 months

The full queue analysis for this market, which covers the share of projects that give up and leave the queue (the withdrawal rate), how much of the queue is data centers, and the sources, is available through /api/v1/queue/caiso with a paid key. These are generation and storage queue figures: they show interconnection-system congestion, not a typical large-load connection wait.

Seller view: A deep queue is both your own time-to-revenue and a moat against competing supply; what matters is the effective supply likely to complete after withdrawal, not the headline queue.

Realized cost band

What a large electricity user pays for power here on one declared case, 100 MW contracted demand, 95% load factor, HV service, per megawatt-hour. Not the wholesale price and not the sticker tariff: energy plus the grid, delivery and other charges that land on the bill. It is a range, because real contracts vary, and it is labelled by how it was built.

Recurring cost, delivered

$95 to $155 per MWh

Midpoint about $120 per MWh

How this band was built

triangulated

From 3 public fragments

What builds the $120 midpoint

$42

$48

$22

Wholesale energy$42

Non-bypassable & policy charges (PCIA, wildfire)$48

Delivery & network$22

Rule 30 transmission & other$8

All-in delivered$120 /MWh

How the $120/MWh figure is built up, component by component, for 100 MW contracted demand, 95% load factor, HV service. The split is our estimate; the total is the midpoint of the compiled band (triangulated). Recurring cost only: customer-funded connection capital is a separate one-off and is not included. California's non-bypassable charges, including the Power Charge Indifference Adjustment, plus wildfire and policy costs, and under the new Rule 30 the upfront transmission cost for a large load, push the delivered cost far above the wholesale price. Anchored to published figures (CPUC on data-center cost allocation).

Where the cost lands

$120

Low $95Midpoint $120High $155

A band, not a single price: the cheaper end is a well-structured contract on favourable terms, the higher end a less optimised one. The midpoint is our best central read.

What is in the number: Wholesale energy near $42 per MWh, plus California's heavy non-energy charges: non-bypassable charges, the Power Charge Indifference Adjustment, wildfire and policy costs, and, under the new Rule 30, upfront transmission cost for a large load. The delivered cost runs far above the wholesale price.

California's wholesale price badly understates the delivered cost. A large load carries some of the highest non-bypassable and delivery charges in the United States, so an all-in figure of roughly $95 to $155 per MWh is realistic, well above the $42 wholesale reading. On this basis California is an expensive market for a new large load, not a cheap one.

This market's band is free here; the ranked cross-market table with every market's precise midpoint is the Analyst Desk. See the ranked view.

Basis: triangulated from public sources, in US dollars per MWh delivered to a large high-load-factor load, excluding refundable taxes. Sources: CPUC on data-center cost allocation · CAISO large loads and Rule 30.

Seller view: This delivered price is the level a competitive supply offer must beat, and the revenue ceiling a merchant plant works against here.

Data provenance and freshness

What we hold for this market, field by field. Each tier below is assigned from the evidence actually held for that field, with provenance. A low tier means we looked and it is thin; it is not a verdict on the market.

cost: M3connection: M2reliability: M2carbon: M2regulatory: M2local capacity: not_assessed

Against a Standardized Project Case, the binding field is connection, reliability. That is what a standardized case would turn on here; a readiness result for your own project depends on your own requirements, siting and utility, which this market-level read does not know.

Read against other uses: Discovery and monitoring: M2 · Market comparison: M2 · Project Case with a carbon requirement: M2 · Conditional site diligence: insufficient.

Depth is not a rating strength, a confidence score or a feasibility conclusion. An aggregate is only ever shown for a named use case, and equals the lowest tier across that use case's required fields. Definitions v1.0. See the full coverage matrix.

How solid the data behind this rating is, on two separate axes plus recency. Source reliability is how measured the numbers are, as opposed to triangulated or modelled. Coverage is how many of the decision-relevant data dimensions (reliability, connection, and cost) are compiled for this market. The two are kept apart because they answer different questions: a market can have strong sources on the little that is covered, or broad coverage that still leans on models. Neither grades the rating itself. The rating is a cited opinion, graded separately and falsifiably by the public track record and baseline measurement plan.

Source reliability

High

2 of 3 data layers measured

Coverage

Full

3 of 3 dimensions: reliability, connection, cost

Last reviewed

June 2026

per-layer vintages below

Layer	Method	Vintage	Freshness	Source
PGIQ Rating opinion	opinion	June 2026	Current	PGIQ methodology
Reliability	measured	2024	Fresh	EIA Form 861, Schedules 3B and 3C (annual electric power industry report) (IEEE 1366 major-event treatment, customer-weighted blend of 3 utilities, regional context only)
Interconnection queue	measured	end-2025 (LBNL 2026)	Fresh	LBNL Queued Up 2026
Realized cost	triangulated	2026	Fresh	CPUC on data-center cost allocation

Freshness reflects each layer's refresh cadence: reliability annual to three-yearly, capacity-auction and queue yearly, tariffs every year or two. The full cross-market freshness dashboard is at /data-quality.

What this market can and cannot answer yet

No market-level read closes a project case on its own, and saying only that would waste the evidence we do hold. Below is what is established, what is open, and what to do next.

What is established

Recurring cost band $95 to $155 per MWh, midpoint $120, basis triangulated, against the 100 MW archetype
Historical utility-territory delivery performance 177.14 minutes per year (2024)
Historical bulk-system performance (event-based)
Forward resource adequacy (assessed)
Typical interconnection wait about 60 months (generation and storage queue, not a load wait)

What is open

Contractual service terms (would change the answer)
Designed site resilience
local_capacity evidence

Who would actually serve you

Territories in this market, each with its own filed record: Pacific Gas & Electric Co., Southern California Edison Co, San Diego Gas & Electric Co. Which one serves a given site depends on where that site is.
Who runs the connection process: not yet compiled for this market. This is wayfinding rather than evidence, and its absence is a gap in our compilation, not a fact about the market.

Credible ranges today

Cost $95 to $155 per MWh, midpoint $120 (triangulated)
Schedule: interconnection queues here run about 60 months for generation and storage; a large load follows a different process and we do not hold its measured distribution

What could disqualify this market

Evening ramp and supply adequacy.
Wildfire/PSPS and high cost.

Five questions for the utility or system operator

What is the available capacity at the bulk supply point and substation that would serve this site, and what would a 100 MW request do to it?
Is firm service available at 100 MW, and what curtailment rights would you retain over us once we are energised?
What are the milestone dates from a complete application to full firm energisation, and which network upgrades would a 100 MW load trigger?
What is your own territory's SAIDI and SAIFI for the industrial class, on which major-event standard, and what redundancy serves the candidate substation?
What is the all-in delivered rate for 100 MW at a 95% load factor, including demand, network and rider charges, under the tariff that would actually apply?

Documents that would advance the case

The area or substation capacity study, and the current queue position list.
The applicable large-load tariff or the draft electric service agreement.
The interconnection or system impact study, and a specimen connection offer.
The utility's own reliability filing and the substation single-line diagram.
The current tariff sheet with all riders, and any large-load contract terms.

Outlook drivers

↑ Upgrade triggers

Storage build flattens the ramp and frees capacity.
Queue reform speeds connections.

↓ Downgrade triggers

Wildfire-season shutoffs and ramp tightness worsen.
Cost and policy push new build out of state.

Key risks

Evening ramp and supply adequacy.
Wildfire/PSPS and high cost.

Peer comparison

Trades like

NYISO (proven, constrained, pricey)

Ahead

on ecosystem

Behind

ERCOT on cost and access

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Rating history

Jul 2026

Under reviewThe Cost pillar (currently 68) is placed under review. California's wholesale price badly understates the delivered cost once non-bypassable charges, the Power Charge Indifference Adjustment, delivery, and Rule 30 upfront transmission are counted; a large load's all-in runs closer to $95 to $155 per MWh, an expensive market, not a moderate one. Reassessing the Cost score; tier could move down as the cost read weakens.

Trigger: Realized-cost review of California non-bypassable and delivery charges (Jul 2026)

Jun 2026

AffirmedNamed in the FERC show-cause suite; preliminary stage, tier holds, monitoring.

Trigger: FERC Section 206 show-cause order (18 Jun 2026)

June 2026

New ratingNew rating: Tier 3 Workable assigned.

🔒 The full time series behind CAISO (California), how its score, recurring cost, and interconnection queue have moved month by month, is part of the Analyst Desk. The rating actions above are always free.

Every rating action is dated and explained, and the log is only ever added to, never edited. Reviews happen on a regular schedule and whenever a significant event occurs. "Affirmed" means we reviewed a development and the tier held; "Under review" means a significant item is being assessed and the rating could change.

Score history

How CAISO (California)'s reliability-adjusted score and tier have moved, month by month. Part of your Analyst Desk.

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How does CAISO (California) compare to the other 78 markets?

This page is our full read on CAISO (California) alone, and it is free. To decide where a large load should actually go, you need every market side by side, ranked on recurring cost and time-to-connect, with the history and alerts when your shortlist moves. That is the Analyst Desk.

With your Analyst Desk, compare CAISO (California) against every market side by side, ranked on recurring cost and time-to-connect, with the full history and shortlist alerts.

+ Add to your shortlist Recurring cost, ranked Connection friction, ranked Get the Analyst Desk →

Cite as: PowerGridIQ Rating, "CAISO (California)" (Tier 3 Workable), as of June 2026. A proprietary, directional screen for siting a large electricity load; not a connection guarantee, and not investment, engineering or procurement advice. Sources and methodology at powergridiq.com/methodology. © PowerGridIQ.