Gas Swing Contracts | Volume Tolerance & Settlement

Request the settlement calculation before approving flexibility

Have the supplier show both sides numerically using the same units. A flat-rate comparison cannot model an undefined swing settlement, and utility balancing is a separate obligation.

Worked example: identify what the tolerance actually protects

Assume a hypothetical monthly reference quantity of 1,000 units with a stated ten-percent band. The band spans 900 to 1,100 units. If actual use reaches 1,200, it is 100 units above the upper band and 200 above the reference. The contract must establish which quantity is settled and how; the word tolerance alone does not answer that question.

Ask the supplier to calculate this overrun and an equivalent shortfall, identifying the price reference, period and any additional charges or credits. Then test a month inside the band and a change that leaves annual volume unchanged but shifts it between months. Keep supplier swing terms separate from utility scheduling and balancing rules. Do not assume a symmetric settlement or unlimited flexibility from a brief proposal label.

Keep supplier swing separate from utility balancing

A supplier’s tolerance can address differences from a reference volume while the utility or transporter imposes its own scheduling and imbalance conditions. FERC’s transportation material explains why capacity and operational service are separate from the commodity transaction. Ask who owns each obligation and whether the supplier’s quoted flexibility includes the utility consequences. A product label is not a substitute for the defined settlement. FERC: firm capacity release and secondary transportation markets.

Test the boundary, the period and the direction

Request calculations exactly at a tolerance boundary, just beyond it, and for an equal shortfall. Then shift the same annual quantity between winter and summer months. Record whether the comparison uses monthly or annual bands, absolute or percentage quantities, and one-way or symmetric treatment. Confirm the price reference and settlement date rather than assuming the supplier pays back unused volume at the purchase price. EIA: natural gas volume, heat content and energy units.

A settlement worksheet with all four reference fields

Record reference quantity, tolerance boundary, settlement quantity and settlement price separately. Add the measurement period and payment or credit date. Test a case inside the band, above it, below it and at the exact boundary. Keep the supplier’s written responses so an ambiguous example is not treated as a binding promise. Ask what changes if the same annual use moves into a different month. Do not combine monthly tolerance protection with an annual budget as though they measured the same exposure.

Use the appropriate planning tool

Monthly gas budget: Use a revised monthly quantity forecast to identify exposure; the budget tool does not apply a contract’s swing settlement rules.