Oil, Gas & Energy · March 2026 · 8 min read
Integrated Monte Carlo for gas-to-power bankability
Most gas-to-power programmes that stall in structuring have three individually reasonable documents — a GSA, a PPA and a sovereign support package — that were never stress-tested against the same set of scenarios at the same time.
The argument
An integrated bankability model runs upstream gas economics, midstream tolling, plant availability, tariff waterfall and sovereign exposure as a single Monte Carlo, with correlated FX, gas-price and demand-shortfall paths. The DSCR is measured across scenarios and the sovereign contingent liability is priced at the tail tail. The gaps that show up in that view are always structural — a take-or-pay that does not match the offtake, a guarantee that carries a liability the ministry of finance cannot bear, a tariff that clears the base case but not the demand-shortfall scenario.
What we see in the field
On a recent programme, the integrated run surfaced a mismatch between the GSA's take-or-pay volume and the PPA's dispatch profile that the individual workstreams had not seen. Closing it required a redraft of two clauses. Without the run, that mismatch would have appeared as an unfunded liability in year three of operations.
What it changes
For sponsors, running the three documents through a single stochastic model is the cheapest way to find the structural gaps before lenders do. For ministries, pricing the sovereign contingent liability at the tail tail is the difference between a support package the treasury can carry and one it cannot.
Where to start
Before the next lender meeting, ask for a single integrated Monte Carlo across the GSA, the PPA and the sovereign package. If the DSCR and the contingent liability cannot both be shown at the tail tail, the deal is not yet bankable.
