Panamint Capital arranged $1.8 billion in a single week to build two solar projects on the same reclaimed coal mine in central Texas. The two facilities come to 957.67 MWac between them, which makes the package the largest Enerdatics records for solar construction on one site in ERCOT. Most of that money is not debt Panamint will still be carrying when the projects switch on.
Key takeaways
- Panamint Capital secured a $1.8 billion two-phase debt facility announced on 4 November 2026 for the Big Rooter East and Big Rooter West solar projects in Robertson County, Texas, with Lloyds Bank, MUFG Bank and Sumitomo Mitsui Banking Corporation as joint lead arrangers and green loan coordinators.
- Big Rooter East is a 658 MWdc and 554.47 MWac solar PV facility and Big Rooter West is 491 MWdc and 403.2 MWac, giving a combined 1,149 MWdc and 957.67 MWac, with both projects expected to be operational by August 2028.
- The $1,014 million tranche raised against Big Rooter East comprises $336 million of secured construction-to-term debt, a $587 million tax equity bridge facility and a $91 million letter of credit.
- The $769 million tranche raised against Big Rooter West comprises $240 million of senior secured construction-to-term debt, a $461 million tax equity bridge facility and a $68 million letter of credit.
- Both projects sit at the Twin Oaks Power Station and Calvert Mine site on reclaimed coal mining land and use the existing interconnection infrastructure, with a 200 MW battery in active development on the same site and SOLV Energy delivering construction and operations.
What is a tax equity bridge facility doing inside a construction loan?
A tax equity bridge is a loan the banks advance against a tax equity investor's committed future contribution. The investor funds at or close to commercial operation, when the project is built and the federal tax credits it generates become usable. Until then someone has to pay the contractors, so the banks lend the money and are repaid out of the tax equity contribution rather than out of the project's revenue. It is construction working capital standing in for equity, and it is designed to disappear.
That is why the headline figure and the balance sheet figure are different things. Add the two tranches and the bridge components come to $1,048 million of the $1,783 million raised, or just under 59 percent. The construction-to-term debt, the part that converts into a term loan and sits against the projects for their operating life, totals $576 million. The remaining $159 million is letters of credit, which are credit support rather than drawn cash, typically backing obligations to the offtaker, the grid operator and the equipment suppliers.
What does Panamint actually owe per megawatt?
The answer depends on which of the three components you count, and on which capacity figure you divide by. Solar projects carry two ratings. MWdc is the nameplate rating of the panels, and MWac is what the inverters can actually export to the grid. Big Rooter is 1,149 MWdc against 957.67 MWac, a ratio of about 1.2, so the choice moves any per-megawatt figure by a fifth before anything else happens.
Measured against export capacity, the full package prices at $1.86 million per MWac. Strip out the bridge and the letters of credit and the permanent debt prices at $0.60 million per MWac. The gap between those two numbers is the tax equity Panamint has lined up but not yet received, which the bridge sizing implies at roughly $1.09 million per MWac. For comparison, Aligned Climate Capital's $387 million community solar facility was written as construction-to-permanent debt specifically so that none of it needed refinancing at switch-on, which is the opposite structural choice. And Deriva Energy's two October construction loans showed how far per-megawatt pricing can move between projects for reasons that have nothing to do with technology.
Why build this on a closed coal mine?
Because the grid connection is already there. The Twin Oaks Power Station was a lignite-fired plant, and a retired thermal station leaves behind a substation, a switchyard and an interconnection agreement sized for several hundred megawatts of export. Developing on the reclaimed mining land next to it means the project inherits that capacity instead of joining an ERCOT interconnection queue and waiting for a study cycle.
The siting choice shapes the financing as much as the tax structure does. Lenders underwriting a 958 MWac build need to believe the asset can export when it is finished, and existing infrastructure removes the largest timing risk from that question. The 200 MW battery still in development on the same footprint points the same way, since a co-located battery shares the connection rather than needing its own.
Enerdatics records 74 solar financings tagged to ERCOT since the start of 2024. Twelve of them are $800 million or larger, and across those twelve the two Big Rooter tranches together, at $1.78 billion, are the largest raised for solar construction on a single site. The next largest single-site package is Vesper Energy's $1.09 billion for Hornet Solar in January 2024, followed by Doral Energy's $913 million for Cold Creek 2 in March 2026.
What does the deal signal for ERCOT solar?
That the binding constraint on large Texas solar has moved from land and lenders to grid access and tax credit monetisation. Three international banks were willing to arrange $1.8 billion in one go, so bank appetite is not the limit. What the structure reveals is that more than half the construction cost is being carried against tax equity that has not funded yet, which makes the tax credit transfer market, rather than the loan market, the thing that determines whether projects of this size can be built on this timetable.
The second signal is about brownfield siting. Reusing a retired coal plant's interconnection is becoming a financing advantage rather than a planning curiosity, and ERCOT has a long list of retired or retiring thermal sites with export rights attached. A developer that can assemble reclaimed land next to one of them starts with the asset that is hardest to buy. Panamint has now done it twice on the same footprint.
Frequently asked questions
How much did Panamint Capital raise for the Big Rooter solar projects?A total of $1.8 billion across two tranches announced on 4 November 2026: $1,014 million against Big Rooter East and $769 million against Big Rooter West. Enerdatics records the two as phases of one facility.
How large are Big Rooter East and Big Rooter West?Big Rooter East is 658 MWdc and 554.47 MWac and Big Rooter West is 491 MWdc and 403.2 MWac, a combined 957.67 MWac. Both are in Robertson County, Texas, and both are expected to be operational by August 2028.
Who is lending to Panamint Capital?Lloyds Bank, MUFG Bank and Sumitomo Mitsui Banking Corporation are joint lead arrangers, bookrunners and green loan coordinators, with MUFG as administrative agent and CSC Delaware Trust Company as collateral agent. White & Case and Jackson Walker advised Panamint, and Milbank advised the lenders.
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