If the "Fuel Adjustment Charge" line makes no sense — but it's clearly not small
If you run a plant, a hospital, a school system, a city, or a large commercial operation — and you stare at the Fuel Adjustment Charge or Fuel Rider line and think, "I have no idea what this is, but it's not small" — this guide is for you.
You're already spending more time on electricity than any normal person would want to, because utilities and vendors keep adding cost and complexity. Fuel adjustment is one of the most confusing pieces — and one of the most volatile. The goal here is to get you to where you can sit down with finance and your board and have a clear conversation about it.
How can you mitigate the financial impact of fluctuating fuel adjustment charges on your energy budget — when you can't control the markets and can't opt out of the mechanism?
Short version: you can't make it disappear, but you can do three things — understand your exposure, track the line item over time, and deliberately reduce the kilowatt-hours exposed to it. Part 1 is understanding and tracking. Part 2 goes deep on the mitigation levers.
In a regulated market — which is where most C&I customers sit — your utility has two kinds of cost allowance. Understanding the difference is the whole foundation.
The fixed side — building and maintaining plants, poles, wires, transformers. Set in a formal, lengthy, public rate case and baked in for years. Inside it sits an agreed base fuel cost: a multi-year forecast.
So a fuel adjustment charge is a correction factor — the utility saying, "What we actually paid for fuel was different from what base rates assumed, so here's the true-up." Names vary: Fuel Adjustment Charge, Fuel Cost Adjustment, Fuel Rider, Purchased Power Adjustment. Same idea.
The true-up is simple arithmetic. Every month or quarter, the utility compares what it actually paid for fuel to what base rates assumed, divides the gap across all the kilowatt-hours it sold, and that becomes your per-kWh adjustment.
Positive when fuel ran hotter than the forecast — it adds cost. Negative when fuel came in cheap — technically a credit. In recent years, most operators have mainly seen positive numbers. It's applied to your kWh and shows up as its own line with a rate and a dollar total.
Why utilities use it
Three reasons, and on paper they're reasonable — this is overseen by regulators through prudence reviews, and it's structured as a pass-through, not a profit center.
Without it, a fuel spike would gut the utility until the next rate case — not sustainable for a grid you need to work on demand.
Peeling fuel into a rider lets regulators leave base rates alone longer while still recovering real fuel cost.
Without a rider, a cautious utility bakes a high fuel guess into base rates forever. The rider lets base rates be lower and corrects either way.
When you budget electricity, you budget the base energy rate and demand charges. But this floating per-kWh line can swing from 10% of your bill to 20, 30, or more. That's money that wasn't in the budget when you priced your products.
We've watched the cost of fuel adjustment climb nearly 3,000% in a year on a specific rate — adding almost 3¢ per kWh on top of everything else. Consume millions of kWh a month and that's real money nobody budgeted. Those customers didn't get less efficient. They just happened to be standing in the wrong place when certain decisions met certain markets.
Harder to price what you sell. Harder to evaluate capital projects — if you don't know how much of your bill floats with fuel, your payback math is incomplete.
This month's FAC often reflects fuel costs from a prior period — a history lesson. When someone asks "why did this happen now, what did we do?", the honest answer is usually: nothing. It's the cost of the system you're on.
| The myth | The reality |
|---|---|
| "The utility is getting rich off this line." | Under a standard FAC they can't profit on fuel — it's a dollar-for-dollar pass-through, scrutinized by the commission. Argue about "prudent" and about asset management; the mechanism itself isn't a margin line. |
| "It's a hidden fee." | Not hidden — buried in small print, maybe, but the mechanism is spelled out in the public tariff. You shouldn't need a law degree, but it's no secret. |
| "They could just buy cheaper fuel." | They run under reliability requirements and long-term contracts — they can't cancel everything and buy the day's cheapest. Not every decision is perfect, but it's not "they're lazy" either. |
| "Go renewable and the FAC disappears." | On-site generation cuts the kWh you buy and lowers exposure (more in Part 2) — but any power you still draw from a fuel-leaning grid carries some version of a fuel or purchased-power adjustment. |
| "It's just a percentage of my bill." | It's a rate per kWh, not a percentage. Its share of the bill depends on how high the rate is that month and how many kWh you used. |
Standing alone, the FAC is neutral. Markets move; utilities need a way to recover real fuel cost. What matters is how big a share of your bill it becomes and how violently it moves — and that's driven by how your utility manages generation over time.
A utility that builds and retires assets with customer cost and stability as the top priority — diversifying the mix, avoiding over-reliance on one volatile fuel — keeps your exposure lower than competitors in other territories.
A utility that makes generation decisions driven more by ideology than customer cost — pushing more of your bill into fuel and purchased power that float with markets — turns the FAC into a real burden. You're overexposed to someone else's bets.
There's nothing inherently wrong with a fuel adjustment mechanism. But the trajectory of decarbonization and the "energy transition" has, observably, been prioritized above the impact on customer cost. We can generate adequate energy at significantly lower cost than we currently do — so when a utility overexposes its customers to fuel volatility through ideological asset management, that's a net negative you feel every month. You can't change their mix from your side of the meter. You can decide how seriously you track it and how aggressively you shrink the kWh exposed to it.
The giant red flag is your own blind spot
This isn't about catching a vendor's bad phrase. The real red flag is a lack of clear understanding of what drives the variance on your bill. Without that, every energy project's ROI is designed against an incomplete picture. So it's not a question to ask — it's a dynamic to track:
The FAC rate itself — cents per kWh, every month. Put it in a spreadsheet. Look at it over 12 months, then 3 years. You want the pattern.
Its share of your total bill — $20k of a $100k bill is 20%. Log it monthly alongside the rate.
Your utility's generation mix — heavy on natural gas? Coal? Meaningful nuclear or hydro? The more concentrated in a volatile fuel, the more sensitive your FAC.
The commodity trend behind that mix — gas-heavy? Keep a rough eye on natural gas (Henry Hub). You don't need to trade it, just avoid surprises.
5–10 years of history — where did this line usually sit, and what were the extremes? That tells you "normal" versus "unusual territory."
When the FAC is a nuisance — and when it's a real disadvantage
- Your utility runs a diverse, well-managed mix, so the line stays modest and rarely spikes.
- You track it — rate, % of bill, mix, commodity trend — so nothing surprises you.
- You fold the floating piece into project payback math, not just the base energy rate.
- Your utility is concentrated in a volatile fuel, so the line swings hard and large.
- You don't track it and get blindsided — pricing and budgets built on the base rate alone.
- You're an energy-intensive operation competing against peers in calmer territories.
You can't make fuel adjustment charges disappear — but you can stop being surprised by them.
Track the rate, know its share of your bill, understand your utility's fuel mix, and deliberately shrink the kilowatt-hours exposed to it. That turns the FAC from a mystery that wrecks your budget into one more variable you manage with intention.
The mitigation levers — energy efficiency, on-site generation, demand response, and procurement strategies — to shrink the kilowatt-hours exposed to fuel adjustment or stabilize your all-in rate. Part of the complete C&I energy series at Energy Answers.
| Fuel Adjustment Charge (FAC) | A variable per-kWh line item passing through the gap between actual fuel cost and the base fuel cost baked into rates. Also: Fuel Rider, Fuel Cost Adjustment, Purchased Power Adjustment. |
| Base rate | The fixed side — plants, poles, wires. Set in a rate case for years; contains a forecast "base fuel cost." |
| Base fuel cost | The multi-year fuel forecast embedded in base rates. The FAC trues up the difference against what fuel actually cost. |
| Rate case | The long, public regulatory process to change base rates. Riders float without one, on ~30-day administrative updates. |
| Prudence review | The commission's check that fuel was bought reasonably and efficiently — the guardrail on a pass-through. |
| Generation mix | The blend of fuels a utility runs (gas, coal, nuclear, hydro, renewables). Concentration in a volatile fuel makes your FAC swing more. |
| Henry Hub | The U.S. benchmark price for natural gas. A leading indicator for a gas-heavy utility's FAC. |
| The lag | This month's FAC often reflects a prior period's fuel costs — why it feels disconnected from anything you did. |
Energy Answers · by Daniel Burke · Energy Decision 05 · Fuel Adjustment Charges, Part 1