The essential point: A FERC interconnection bond is a surety guarantee replacing cash and letters of credit for generator interconnection deposits under FERC Order 2023-A (March 2024). Accepted across MISO, PJM, CAISO, SPP, NYISO, ISO-NE, and directly-interconnected utility territories. For a developer with multiple projects in queue, replacing cash deposits with surety bonds can preserve tens of millions of dollars of deployable capital.
Following FERC Order 2023-A (March 2024), surety bonds are now an approved form of financial security for generator interconnection deposits. We write interconnection bonds for utility-scale solar, wind, and battery storage projects across MISO, PJM, CAISO, SPP, NYISO, ISO-NE, and directly-interconnected utility territories nationwide.
What an interconnection bond is
An interconnection bond is a surety bond that secures a renewable energy developer's financial obligations under a Large Generator Interconnection Agreement (LGIA) or its functional equivalent at an Independent System Operator (ISO) or Regional Transmission Organization (RTO). It guarantees that the developer will fund its share of network upgrade costs, study deposits, and commercial readiness deposits as those obligations come due.
The bond serves the same commercial function as a cash deposit or letter of credit — but with materially better capital efficiency. Rather than posting cash for four years while a project moves through the interconnection queue, the developer posts an annual premium and preserves the underlying capital for parallel deployment.
Why FERC's Order 2023-A matters
Before March 2024, interconnection customers were generally limited to two forms of financial security: cash deposits or irrevocable letters of credit. Both options tied up significant developer capital — often seven figures for a single 138-kV tie-in to the bulk transmission system — for the entire duration of the interconnection study and construction process.
FERC Order No. 2023-A, issued in March 2024, expressly accepts surety bonds as a form of financial security for commercial readiness deposits and study deposits in the generator interconnection process. The change applies across all major ISOs and RTOs. For an active developer with a dozen projects moving through interconnection queues simultaneously, the cash-preservation implications are material — enough to fund an entire additional development pipeline in some cases.
Network upgrade costs and the interconnection queue
The interconnection process at every ISO and RTO involves a queue of projects competing for grid capacity, a series of studies to determine each project's impact on the transmission system, and the assignment of network upgrade costs to each project according to its causation of required upgrades.
Network upgrade costs are the single largest interconnection cost category. They represent the transmission facilities that must be built or reinforced to accommodate the specific project. For a large solar or wind project, network upgrade costs can range from a few million to over $100 million. The developer's LGIA obligation is to fund these upgrades — typically through cash deposits held by the transmission provider — until the upgrades are completed and reconciled.
ISO and RTO variations
Each ISO/RTO administers its own interconnection tariff, and the specific security requirements vary by jurisdiction. Selected highlights:
- MISO: Deposit-per-milestone (DPP) structure with escalating security requirements as the project advances through the queue.
- PJM: Revised queue reforms have imposed substantial front-loaded security requirements.
- CAISO: Distinct queue reform framework with specific rules for standalone battery storage.
- SPP: Deposit-return-in-tranches structure varies by project size.
- NYISO: Class Year process with specific security amounts published annually.
- ISO-NE: Specific security requirements under FCA framework.
Directly-interconnected utility territories (Southeast, most of the Mountain West, parts of Texas outside ERCOT) operate under FERC's OATT with utility-specific tariff variations.
Withdrawal penalties under Order 2023
Alongside expanded security options, FERC Order 2023 imposed materially stronger withdrawal penalties for projects that exit the queue after specific milestones. Projects that withdraw after certain queue milestones forfeit posted security to the transmission provider under specific tariff formulas. This makes the security instrument selection more consequential — a cash deposit forfeited is unrecoverable, whereas a surety bond forfeiture triggers the surety's indemnity rights against the principal.
Sophisticated developers structure their interconnection security portfolio to align the risk of forfeiture with the specific risk profile of each project. Surety bonds are particularly well suited to projects with elevated queue-exit risk, since the developer retains the underlying capital rather than posting it upfront.
Bond amount and premium
Interconnection bond penal sums track the specific tariff-mandated deposit amount for the applicable queue stage. Common ranges:
- Small commercial: $250,000 to $2 million
- Mid-market utility-scale: $2 million to $25 million
- Large utility-scale: $25 million to $150 million+
Premium rates on interconnection bonds run from 0.5% to 2% of penal sum annually, subject to underwriting. Bond terms follow the interconnection milestone schedule; most bonds renew annually or on each milestone gate.
Underwriting considerations
Interconnection bond underwriting focuses on:
- Project maturity. Progress through study milestones, executed LGIA, and construction schedule certainty.
- Sponsor identity and financial strength. The developer or sponsor entity behind the SPV holding the interconnection position.
- Land control and permitting status. The likelihood that the project actually reaches COD.
- Offtake status. Executed PPA, corporate PPA framework, or merchant strategy.
- Project finance visibility. Construction lender engaged, tax equity term sheet in place.
Capital preservation: a worked example
Consider a developer with a 200 MW solar project entering an ISO queue with a $15 million study deposit obligation and an anticipated $60 million network upgrade obligation to be posted incrementally over four years.
| Security form | Capital tied up (4 years) | Annual carrying cost |
|---|---|---|
| Cash deposit | $75 million | Opportunity cost of ~$6M/year at 8% target IRR |
| Letter of credit | $75 million bank credit line | ~1.5% LOC fee ($1.125M/year) + reduced borrowing capacity |
| Surety bond | Indemnity only | ~1% premium ($750K/year) |
Across the four-year study and construction window, the developer preserves $75 million of deployable capital by using a surety bond rather than posting cash. That capital funds parallel projects, produces its own IRR, and materially improves the developer's overall program economics.
Also needed by most GCs
Contractor license & permit bonds — all 50 states
Every general contractor working across state lines needs multiple L&P bonds. Surety One writes contractor license bonds, municipal permit bonds and combined license/performance bonds nationwide.
How to apply
Email underwriting@suretyone.com or call (800) 373-2804. Include the specific tariff deposit amount, the ISO/RTO or utility obligee, the project description, and the required bond form.
Related pages: renewable energy bond hub, EPC performance bonds, PPA bonds.