Why blended $/therm beats the marketer quote
Marketers and LDCs may quote a commodity price per therm. Your statement adds customer charges, balancing adjustments, riders, and taxes. Gas dryers dominate therms at many stores—California IOU CASE work measured 0.36 therm per load on a 30-pound gas dryer, with annual modeled use of 732 therms at 5.52 loads per day for one machine.
Blended math tells you what left the bank account per therm consumed. That is the metric to track year over year and to support CLA-style due diligence where utilities sit near 20–25% of revenue nationally.
Formulas and table
Pull numerators and denominators directly from the bill detail pages.
| Metric | Formula |
|---|---|
| Blended $/therm | Total gas charges ÷ Therms |
| Commodity $/therm | Gas supply subtotal ÷ Therms |
| Delivery $/therm | Delivery subtotal ÷ Therms |
| Therms per day | Therms ÷ Billing days |
| Implied dryer therms | Dryer count × loads/day × days × therms/load (from spec or test data) |
Example method without national rate assumptions
If a bill shows 420 therms and $1,680 total, blended price = $1,680 ÷ 420 = $4.00/therm. When commodity subtotal is $980 and delivery is $520, commodity rate = $980 ÷ 420 ≈ $2.33/therm and delivery ≈ $1.24/therm. Remaining dollars are taxes and fixed fees—assign them explicitly rather than ignoring them.
Compare implied dryer therms using 0.36 therm per load as a benchmark for 30-pound gas dryers, adjusting for your fleet. Unexplained therms may include gas water heating or space heat.
Supply procurement versus therm reduction
A lower commodity $/therm from a new marketer contract reduces the supply slice only. Fixing leaking gas valves, tuning burners, or reducing idle hours lowers therms—a consumption lever. Texas routes gas through LDC regulation under the Railroad Commission without ERCOT-style mandatory marketer choice for all customers.
In Atlanta's AGL model, marketer commodity and AGL delivery may appear separately—calculate effective rates for each layer.
Owner checklist
Run monthly before renewing gas supply agreements.
- Record blended and split $/therm in a spreadsheet by month.
- Normalize partial months using therms per day.
- Compare same month prior year for weather-driven space heat.
- Log estimated versus actual reads.
- Archive calculations with bills for resale packets.
