On Wednesday, November 4, 2026, Invenergy Transmission filed a complaint with the Federal Energy Regulatory Commission arguing that the Midcontinent Independent System Operator’s capacity market takes the reliability value of merchant high-voltage direct-current lines and pays nothing for it. MISO counts the capacity value of HVDC lines when it decides how much capacity to buy in its Planning Resource Auction — reducing the amount it acquires — but its rules prevent those lines from being accredited as capacity resources or paid for the capacity value they provide. The complaint, filed under section 206 of the Federal Power Act, asks FERC to find the arrangement unjust and unreasonable and to order MISO to open the capacity market to merchant HVDC lines.
The filing is the merchant-transmission side of the capacity-market fight that broke open in the same week. On Tuesday, Exelon asked FERC to order PJM to abandon its three-year-forward capacity auction schedule in favor of a prompt auction held two months before the delivery year, starting with 2030/31. Two complaints, two operators, one question: whether the capacity markets pay for the resources the grid actually relies on. Exelon’s complaint is about when the market buys capacity. Invenergy’s is about what it buys — and whether a transmission line that moves power across regions counts as capacity at all.
The free-rider argument
Invenergy’s argument is narrow, and its narrowness is the point. The company does not ask FERC to redesign MISO’s resource adequacy construct or grant cost-of-service rates — merchant lines recover costs through negotiated rates. What Invenergy says is that MISO’s own planning already treats an HVDC line as a capacity resource; it just does not pay for it as one.
The mechanism is straightforward. When MISO calculates the Planning Reserve Margin Requirement — the capacity its load-serving entities must hold — it accounts for the transfer capability HVDC lines provide, since those lines can deliver power from outside the region when MISO is short. That accounting reduces the capacity MISO needs to procure. The benefit flows to MISO’s customers in the form of lower capacity obligations. The line owner, meanwhile, has no product to sell into that market: MISO’s rules do not let a transmission facility be accredited as a capacity resource, and there is no other avenue for the line to be compensated for the capacity value it provides.
“MISO cannot rely on that capacity, to the benefit of other customers, while refusing to provide any avenue for the entity that provides that capacity to receive commensurate compensation,” Invenergy said in the complaint. The sentence is the whole case in one line.
The commercial consequence follows from the structure of merchant transmission. “Interregional merchant HVDC transmission lines only receive compensation if there is a product or service — such as capacity — for which they can transact with potential customers,” the complaint says. “Without capacity payments from MISO, there is no product or service that can be the basis of a merchant-based transaction in MISO.” A regulated transmission owner recovers its costs from ratepayers whether or not its lines clear a market; a merchant developer has only the transactions it can sell. If capacity is not one of them, the line’s value to MISO’s reliability is unmonetizable.
Grain Belt Express, as the worked example
The complaint uses Invenergy’s own project as the example, and the numbers are large enough to matter. Grain Belt Express is a 5-gigawatt, 600-kilovolt HVDC line planned to run about 800 miles from southwest Kansas to Indiana, interconnecting with MISO, SPP, and PJM. Invenergy puts the project cost at roughly $11 billion and plans to build it in two phases, the first running from Kansas to central Missouri. In May it awarded nearly $1.7 billion in first-phase contracts to Quanta Services and Kiewit Energy Group, and Invenergy says construction will begin in 2026.
Under the “direct loss of load” methodology MISO is adopting, the complaint says, Grain Belt Express could provide more than 1,800 megawatts of accredited capacity. MISO’s summer auction for the 2025/26 planning year cleared at $666.50 per megawatt-day, roughly 22 times the prior year’s price, as the region’s surplus fell by more than half. At that price, 1,800 megawatts is not a rounding error — roughly the size of a large combined-cycle plant, except that it is not a plant at all. It is the transfer capability of a wire, measured by the load it can keep served when the region’s own resources fall short.
The 1,800-megawatt figure is a function of the accreditation method, and the method matters. MISO’s direct loss of load, or DLOL, methodology — approved by FERC and scheduled to take effect for the 2028/29 planning year — accredits resources based on their performance during the hours when the system is most at risk of losing load, weighting those hours heavily. A transmission line that can deliver power into MISO precisely during those hours scores well under that test. Under the older effective load carrying capability framework, the same line’s contribution was harder to see, because the framework was built around generators, not wires. DLOL is what makes the line’s capacity value measurable — and, Invenergy argues, what makes MISO’s refusal to pay for it indefensible: the operator is adopting a methodology that can quantify the value while keeping a rule that prevents it from being compensated.
A complaint with a history
This is not Invenergy’s first complaint against MISO over Grain Belt Express. In August 2022, Invenergy filed a complaint — Docket EL22-83 — arguing that MISO’s tariff had no transparent process for incorporating advanced-stage merchant transmission facilities into its annual Transmission Expansion Plan base cases. On October 16, 2025, FERC granted that complaint in part, ordering MISO to file within 90 days specifying when and how merchant HVDC projects are incorporated into its transmission planning models. FERC rejected the request to put Grain Belt Express in the Long Range Transmission Plan’s Tranche 1 or Tranche 2.1 base cases, but accepted the core contention: the gap could produce duplicative projects and higher customer rates.
The new complaint is the capacity-market sequel. In the first, MISO was not counting the line at all, and Invenergy said the omission would lead to duplicative transmission built at ratepayer expense. In the second, MISO counts the line — where it reduces what the operator must buy — and Invenergy says the counting without payment is the problem. The merchant line’s value is recognized wherever recognition is free, and unrecognized wherever recognition would cost something.
The context also includes a setback for the project. In July, the Department of Energy cancelled a $4.9 billion conditional loan commitment for the project’s first phase, announced by the previous administration. Invenergy said it still intended to begin construction in 2026. State approvals were unaffected — all four states have approved the line, and Missouri regulators raised its in-state delivery capacity from 500 to 2,500 megawatts. But the cancellation removed the project’s cheapest capital, which makes every remaining revenue stream, including capacity payments, more consequential to the financing.
Why MISO’s rules say no
MISO has not yet answered the complaint, but the rule Invenergy challenges did not arise by accident. MISO’s capacity market accredits resources — generators, storage, demand response, and external resources that can deliver into the region. Transmission is not a resource in that framework; it is the network over which resources deliver. The operator’s own stakeholder materials have been explicit on this point: “MISO does not currently accredit transmission.” Accrediting a line would require deciding who owns the accredited capacity — the line owner, the generator on the other end, or the customer buying the power — and how to avoid paying twice for the same megawatts when the generator itself is also accredited somewhere.
That double-counting concern is real, and it is the strongest argument MISO has. Grain Belt Express will carry power from Kansas wind farms into MISO and PJM. If those generators are accredited in their own markets and the line is accredited separately in MISO, the same megawatts could be paid for twice — once as generation, once as transfer capability. Invenergy’s answer, implicit in the complaint’s use of the DLOL methodology, is that the accreditation should measure the line’s incremental contribution to MISO’s reliability — the load that would otherwise be lost — rather than the nameplate of the generation behind it. Whether that measurement can be made cleanly enough to avoid double payment is the question on which the complaint will likely be won or lost. MISO has, for its part, been working on HVDC capacity accreditation through its stakeholder process since at least August 2025, when its Resource Adequacy Subcommittee took up how HVDC-enabled capacity should be accredited and priced — a pace Invenergy’s complaint can be read as challenging.
The week in capacity markets
The Invenergy complaint landed in the same week as Exelon’s, and the pairing is instructive because the two complaints attack the capacity market from opposite directions. Exelon asked FERC to order PJM to shift to a prompt auction — held two months before the delivery year, starting with 2030/31 — arguing that the three-year-forward schedule produces auctions based on stale load forecasts, resource availability, and accreditation levels. Exelon asked FERC to decide by January 31, the last day before PJM publishes planning parameters for the 2030/31 base auction, scheduled for May. If FERC approves, PJM would hold its December auction for 2029/30 as planned, then its next auction in early 2030.
Exelon’s complaint is about the timing of the market; Invenergy’s is about the scope of what it buys. Both rest on the same premise: the capacity markets, designed in an era of stable load and dispatchable generation, mismeasure the resources the grid now depends on — Exelon because the forward auction commits three years ahead of a fast-moving load forecast, Invenergy because MISO counts a wire’s reliability contribution on the demand side of the ledger and refuses to count it on the supply side.
The two filings also share a procedural reality: FERC does not move on the applicant’s schedule. PJM is reviewing Exelon’s complaint and will reply “at the appropriate time”; its Power Reliability Through Market Design initiative drew more than 30 responses to its request for papers, to be discussed at a November 13 workshop. MISO will have its own answer period, and the January 31 date Exelon requested is a deadline the company asked for, not one FERC has agreed to.
What the complaint would change, and what it would not
If FERC grants Invenergy’s complaint, the immediate effect would be a directive to MISO to develop a method for accrediting merchant HVDC lines — or at least a pathway for their owners to be compensated for the capacity value the operator already counts. That would not, by itself, pay Grain Belt Express anything: the line is not yet built, and accreditation would apply only once it is in service and delivering power during the hours MISO measures. What it would change is the financing: a merchant developer that can point to a capacity revenue stream has a firmer basis for raising the roughly $11 billion the project requires. The same logic would extend to the five merchant HVDC projects MISO has said are in its Attachment GGG interconnection queue: if MISO’s capacity market is going to count interregional transfer capability when it sets its requirements, the market needs a way to pay for that capability, or the capability will be underbuilt relative to what the reliability calculation assumes is there.
What it would not change is the harder problem underneath: the grid’s constraint is not a shortage of lines proposed, but a shortage of lines built, as Fracmoo’s transmission bottleneck explainer has argued. Grain Belt Express has been in development for more than a decade, has state approvals in all four states, and still has not broken ground. A capacity payment would improve its economics, but it would not shorten the permitting, siting, and construction timeline, or resolve the landowner opposition that has followed the project through every state it crosses.
What to watch
Three things will determine whether the complaint becomes a market rule or another entry in the docket. The first is MISO’s answer, due in the coming weeks: whether it defends the current rule as a principled limit — transmission is not a resource — or concedes that the DLOL framework it is adopting can measure a line’s contribution without double-counting. The second is FERC’s disposition: the Commission granted Invenergy’s planning complaint in part a year ago, suggesting sympathy for the argument that merchant lines are undervalued in MISO’s processes — but a capacity payment is a larger step than a planning-model clarification, and the double-counting question gives FERC reason to set the matter for hearing rather than order a remedy outright.
The third is the calendar. MISO’s DLOL accreditation takes effect for the 2028/29 planning year, and Grain Belt Express’s first phase is targeting construction in 2026. If the line enters service around the end of the decade, the accreditation framework will already be in place — the question is whether the payment framework will be there with it. A line that can deliver 1,800 megawatts into a region whose summer auction cleared 22 times higher than the year before is a line the market should want to pay for — and the complaint asks FERC to make it do so.