Fixed vs. Variable Rate Electricity: Which Is Right for Your Business?

When it comes time to sign or renew a commercial electricity contract in Texas, one of the most consequential decisions you will make is choosing your rate structure. Fixed, variable, or hybrid — the option you select determines not just what you pay per kilowatt-hour today, but how much risk you are exposed to over the life of your contract. Choose well and you protect your bottom line. Choose poorly and you could be locked into unfavorable terms for years.

This guide breaks down each rate type, explains who each one is best suited for, and gives you a practical framework for making the right choice for your business.

How Fixed Rates Work

A fixed-rate electricity contract locks in a set price per kWh for the entire duration of your agreement, typically 12 to 36 months. Regardless of what happens in the wholesale electricity market — whether prices spike during a July heat wave or drop during a mild spring — your rate stays the same.

The primary advantage of a fixed rate is budget certainty. You know exactly what your energy charge will be each month, which makes financial planning and forecasting significantly easier. For businesses that operate on tight margins or need predictable operating expenses, this stability is valuable.

The trade-off is that you pay a premium for that certainty. REPs price fixed-rate contracts to account for their own risk — they are guaranteeing your rate regardless of market conditions, so they build a margin into the price. If wholesale market prices stay flat or decline during your contract term, you end up paying more than you would have on a variable rate.

Fixed rates also carry a timing risk. If you lock in during a period of high wholesale prices (mid-summer, for example), you are committing to an elevated rate that may not reflect the annual average cost of electricity. This is why when you sign your contract matters almost as much as what type of contract you choose.

How Variable (Index) Rates Work

A variable-rate or index-rate contract ties your electricity price directly to the wholesale market. In Texas, that typically means your rate is based on ERCOT real-time or day-ahead pricing, plus a fixed adder from your REP to cover their margin and pass-through charges.

The appeal of variable pricing is straightforward: when market prices are low, you pay less. During mild weather months — spring and fall, when neither heating nor cooling demand is driving the grid — wholesale electricity in Texas can be remarkably affordable. Businesses on variable rates during these periods often pay significantly less than their fixed-rate counterparts.

The risk, however, is equally straightforward. When demand surges — during a Texas summer where temperatures exceed 100 degrees for weeks at a stretch, or during an extreme weather event like Winter Storm Uri in 2021 — wholesale prices can spike dramatically. During Uri, ERCOT wholesale prices reached the $9,000/MWh cap for extended periods. Businesses on unhedged variable rates during those events faced bills that were orders of magnitude higher than normal.

Variable rates work best for businesses that have the financial flexibility to absorb price fluctuations and the operational flexibility to reduce consumption during peak periods. They are not a good fit for businesses that cannot tolerate a significantly higher bill during any given month.

The Hybrid Option

A hybrid rate structure, sometimes called a blended or block-and-index contract, combines elements of both fixed and variable pricing under a single agreement. Typically, a portion of your consumption is priced at a fixed rate while the remainder floats with the market index.

Common split structures include 60/40 or 70/30 (fixed/variable), though the specific ratio can be tailored to your business's risk profile and usage patterns. The fixed portion provides a baseline of budget certainty, while the variable portion gives you exposure to market upside when prices are low.

Hybrid rates are particularly well-suited for businesses that want some protection against extreme price events but do not want to pay the full premium of a completely fixed contract. They offer a middle ground that many commercial customers find strikes the right balance between risk and cost.

The key with hybrid contracts is understanding exactly how the split works and what triggers apply to each portion. Not all hybrid structures are created equal — the terms, index references, and settlement mechanisms can vary significantly between suppliers. This is where having an experienced energy broker review the contract details becomes particularly valuable.

Which Is Right for Your Business?

There is no universally correct answer. The best rate structure depends on your business's specific circumstances. Here is a framework to guide the decision:

A few additional considerations:

• Contract length matters. A 36-month fixed rate locks you in for three years. If you sign at a market peak, you are paying above-market rates for a very long time. Shorter terms (12-18 months) give you more flexibility to adjust as conditions change.
• Your industry's seasonality is a factor. If your business uses the most electricity during summer — when wholesale prices are highest — a variable rate means you are buying the most power at the worst possible time. Fixed or hybrid rates hedge that exposure.
• Your consumption volume changes the calculus. High-volume users have more to gain from index pricing because even small per-kWh savings multiply across millions of kilowatt-hours. But the downside is equally amplified.

Common Mistakes to Avoid

In our years of working with Texas businesses on their electricity procurement, we see the same mistakes repeatedly:

• Auto-renewing without checking your rate type. When a contract expires and you are rolled onto a holdover rate, it is almost always a variable rate with a high adder — the worst of both worlds. You get market exposure with none of the cost advantage. Always know when your contract ends and what happens if you do not act. See our guide on when to renew your contract.
• Signing a long-term fixed rate at a market peak. Locking in a 36-month fixed rate in July, when wholesale prices are at their annual high, means you are paying summer-peak pricing for three full years. Timing your contract to coincide with lower market periods (typically fall through early spring) can save you significantly.
• Choosing variable without understanding demand charges. Even if your energy charge is low on a variable rate, your demand charges are a separate line item that can spike independently. A low per-kWh rate does not help if your demand charges are 40% of your bill.
• Comparing rates without comparing total cost. Two contracts with the same per-kWh rate can have very different total costs depending on pass-through charges, adders, and fee structures. Always compare the all-in cost, not just the headline rate.

Make the Right Choice for Your Business

The rate structure decision is not one you should make in isolation or under time pressure. It requires understanding your business's usage patterns, financial constraints, risk tolerance, and the current state of the Texas electricity market.

The smartest approach is to see pricing across all three options — fixed, variable, and hybrid — from multiple suppliers, side by side. That way you can make an informed comparison based on real numbers rather than assumptions. This is exactly what a broker provides: competitive bids from 25+ suppliers, presented transparently so you can choose with confidence.