Duke Energy Interconnection: Find Power, Navigate the Queue, Secure Your Site
Duke Energy Carolinas and Duke Energy Progress run their own transmission system under one shared tariff, and the two combine into one utility on January 1, 2027. Explore DEP/DEC's interconnection process with our interactive step-by-step guide, then use LandGate’s capacity and parcel data to find the sites that can actually connect.
Duke Energy Interconnection at a glance
Title | Description |
|---|---|
Who runs it | DEC and DEP each plan and run their own transmission system under one shared FERC-approved tariff, and each runs its own queue. They combine into one utility on January 1, 2027. The North Carolina Utilities Commission and South Carolina PSC oversee state rules and retail rates. |
Service areas | DEC: western and central North Carolina and upstate South Carolina. DEP: eastern and central North Carolina and northeastern South Carolina. |
Generator study process | A two-phase cluster study. A 45-day window, filed through Duke’s PowerClerk portal, is followed by a 60-day engagement window, Phase 1 (90 days), Phase 2 (150 days, adding stability analysis), a restudy if needed, and a facilities study of 90 or 180 days. |
Current cluster | The 2026 Phase 1 reports came out August 14, 2026. DEC has 11 requests totaling about 3,550 MW, mostly natural gas. DEP has 11 requests totaling about 500 MW, mostly storage. |
Next window | Opens February 1, 2027. Duke hasn’t said whether it will run as one combined cluster or two. |
Generator timeline | Roughly 20 to 23 months from window close to a signed interconnection agreement, plus about 5 months if a restudy is needed |
Generator costs | A $5,000 non-refundable application fee and a study deposit of $150,000 to $250,000 for projects of 80 MW or more, plus a readiness deposit of twice the study deposit. The readiness deposit rises to 5%, 10% and 15% of network upgrade costs, and to 20% at the interconnection agreement. |
Withdrawal penalties | None before the cluster study starts. After that, at least the study deposit, rising to 5% of upgrade costs after Phase 2, 10% during a restudy, 15% during the facilities study and 20% after signing if the plant never operates. |
Large-load threshold | Duke’s large-load technical requirements cover loads connected above 40 kV, typically 50 MW or more, based on long-term projected demand |
How large loads connect | Either through a wholesale customer, such as a co-op or town, which requests service from Duke with a 60-day System Impact Study and 60-day facilities study, or as a Duke retail customer |
Large load security (wholesale path) | For requests of 100 MW or more, 100% of estimated facility and upgrade costs, as a letter of credit or cash |
North Carolina large-load tariff | Proposed. A settlement filed October 6, 2026 would cover loads of 50 MW or more at an 80% load factor, or any load of 150 MW or more, with a minimum bill of 75% of contract demand. An NCUC decision is expected by mid-November 2026. |
Last updated | November 3, 2026 |
Duke Energy Generator Interconnection Process
Generator interconnection,
step-by-step
DEC and DEP study generators in a two-phase cluster, with one shared 45-day window that opens every February 1. Deposits rise at every decision point, from twice the study deposit at filing to 20% of network upgrade costs at the interconnection agreement.
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Check the queue and heatmap. DEC and DEP each post a queue and a heatmap of available capacity at each point of interconnection on their OASIS sites.
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Apply during the February window. Submit through Duke’s PowerClerk portal with proof of at least 90% site control, a $5,000 fee, a study deposit and a readiness deposit of twice the study deposit.
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Customer engagement window. Over 60 days, Duke holds a scoping meeting, and developers sign a Cluster Study Agreement.
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Phase 1 study. Duke studies the whole cluster over 90 days and assigns network upgrade costs. To continue, developers raise their readiness deposit to 5% of those costs within 20 days.
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Phase 2 study. Duke adds stability and short-circuit analysis over 150 days. To continue, developers raise their deposit to 10% of upgrade costs.
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Restudy and facilities study. Duke restudies the cluster if needed. Developers then show 100% site control and raise their deposit to 15%, and Duke designs the facilities over 90 or 180 days.
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Sign the interconnection agreement. Developers post a deposit totaling 20% of upgrade costs and sign the agreement, then construction begins.
Duke Energy Large Load Interconnection Process
Large Load interconnection,
step-by-step
Large loads in FPL’s territory are FPL retail customers, so they work with FPL directly, with no FERC queue for load. FPL’s Large Load Contract Service tariffs apply to new loads of 50 MW or more at one location, with a load factor of 85% or higher. The tariffs took effect January 1, 2026.
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Contact FPL and sign an NDA. The process starts with a non-disclosure agreement, after which FPL shares its large-load process guide. Loads below the thresholds take FPL’s standard commercial rates.
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Pick a site and rate. The customer chooses a site to study and a large-load rate. One option, LLCS-1, covers up to 3 GW of new load in three zones near FPL transmission, chosen for speed to market.
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System study. FPL estimates the time and cost to connect the load, based on the customer’s peak demand and ramp schedule. This takes 6 to 9 months.
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Accept the results. The customer has 6 months to accept the study results and move to agreements.
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Sign the construction agreement. The customer signs FPL’s construction agreement and pays for the facilities FPL builds.
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Sign the service agreement and post security. The customer signs the service agreement and posts performance security within 5 days.
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Build and energize. The customer builds, owns and operates its own high-voltage substation, and FPL energizes the load once both sides are complete.
What's changed recently in Duke Energy interconnection
Last updated November 2026
Duke is merging its two Carolinas utilities, tightening its rules for large loads and running its generator cluster under new financial readiness rules. If your project is in DEC’s or DEP’s territory, check which of these changes apply before the next window or agreement.
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November 1, 2025: New financial readiness rules took effect for generator requests under the FERC, North Carolina and South Carolina procedures.
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April 17, 2026: DEC and DEP first posted heatmaps of available capacity at each point of interconnection.
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August 14, 2026: The 2026 Phase 1 reports came out: DEC with 11 requests totaling about 3,550 MW, mostly natural gas, and DEP with 11 requests totaling about 500 MW, mostly storage.
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October 6, 2026: Duke, North Carolina’s Public Staff and large customers filed a settlement creating the state’s first large-load tariff, for loads of 50 MW or more at an 80% load factor, or any load of 150 MW or more.
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October 15, 2026: An updated version of Duke’s large-load technical requirements took effect for loads connected above 40 kV.
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Coming up: An NCUC decision on the large-load settlement, expected by mid-November 2026; DEC and DEP combining into one utility on January 1, 2027; and the next cluster window opening February 1, 2027.
How LandGate Helps with DEP/DEC Interconnection
Large loads have to choose between two connection paths and meet Duke’s technical requirements above 40 kV. LandGate brings the data behind those decisions into one platform.
Get your projects on the grid faster with reliable transmission data.
Pick a site before the February window
Duke accepts requests only from February 1 for 45 days, and applications need at least 90% site control. Search parcels by criteria such as distance to a substation and available offtake capacity, and see available transfer capacity at transmission-level injection points to find points of interconnection worth applying for.
Know your upgrade exposure
Duke’s deposits climb to 5%, 10%, 15% and then 20% of network upgrade costs as a project advances. LandGate’s automated offtake capacity studies show substation details, capacity results, limiting elements such as transmission lines and transformers, and queue information, so you can spot upgrade risks before committing capital.
Find the right substation & power
Duke’s large load requirements apply above 40 kV. Requests of >100 MW must post security for 100% of facility & upgrade costs. LandGate shows the subtransmission grid (typically between 34.5 kV and 138 kV) with hosting capacity and ATC at the line level. Its Data Center Due Diligence Reports rank the closest substations by capacity available to serve the site.
Lock down the best sites
Duke requires at least 90% site control at application and 100% at the facilities study. LandGate pairs its grid data with proprietary landowner leads, nationwide ownership data and contact info, and a map-based CRM to help you find, secure, and track the right parcels, including off-market properties with the right infrastructure profile.
