The Difference Between a Fully Bundled and Unbundled Energy Rate in Illinois and Which Is Better for Your Business

A fully bundled energy rate is exactly what it sounds like: a single all-in supply rate per kWh that includes all supply cost components—commodity, capacity, transmission, ancillary services, and supplier margin. When you sign a fully bundled fixed-rate contract, your supply cost is locked in at a specific cents-per-kWh charge for the entire contract term, regardless of what happens to any underlying cost component.

What's Included in a Fully Bundled Rate

• **Energy commodity cost:** The actual electricity supply, priced based on PJM wholesale market rates
• **Capacity cost:** Recovery of PJM capacity market charges based on your facility's peak load contribution
• **Transmission cost:** Charges for moving electricity from generators to the local utility distribution system
• **Ancillary services:** Grid reliability charges (regulation, reserves, reactive power)
• **Supplier margin:** The supplier's operating cost and profit built into the supply rate
• **Hedging cost:** The cost of the price risk management the supplier undertakes to offer a fixed rate

The Core Advantage: Price Certainty

The primary benefit of a fully bundled rate is budget certainty. Your supply cost per kWh is fixed for the contract term—typically 12, 24, or 36 months. Wholesale price spikes, capacity market volatility, and ancillary service cost fluctuations don't affect your bill during that period. For businesses that prioritize budget predictability—retail chains, restaurants, healthcare facilities, schools—this certainty has real financial value beyond just the nominal rate.

The Core Disadvantage: Paying for Certainty

Suppliers charge for the certainty they provide. In a fully bundled fixed rate, the supplier must hedge all the underlying cost components and bears the risk of market movements. This hedging cost is built into the rate. In market conditions where volatility is low or where actual costs come in below projections, you may pay more on a bundled rate than you would have on an equivalent unbundled contract.

An unbundled energy rate separates the supply cost components into fixed and pass-through elements. In a typical unbundled contract, the energy commodity cost and supplier margin are fixed, while capacity charges, ancillary services, and possibly transmission costs are passed through at actual market cost.

What 'Pass-Through' Means in Practice

When a cost component is 'passed through,' you pay the actual market cost of that component rather than a pre-hedged rate. If capacity charges run lower than the supplier's hedged estimate in a given period, you pay the lower amount—potentially saving money. If capacity charges spike due to market conditions, you pay the higher amount—potentially costing more than a bundled contract would have.

Index-Based (Fully Unbundled) Contracts

The most unbundled form is an index contract, where even the commodity cost floats with a market index (typically the PJM Day-Ahead or real-time LMP). In this structure, your supply cost tracks wholesale market prices closely—with only a fixed supplier margin remaining constant. Index contracts can deliver lower costs during market downturns but create full exposure to price spikes.

The Potential Advantages of Unbundled Contracts

• Lower average costs when market conditions are favorable (wholesale prices below supplier hedge levels)
• Transparency into the specific cost components driving your bill
• Opportunity to participate in capacity cost reduction programs (since capacity is a direct pass-through)
• More flexible contract structures that may allow partial hedging or layered procurement

Which Is Right for Your Business?

A fully bundled fixed rate is typically better for: businesses that prioritize budget certainty, smaller commercial accounts where the administrative complexity of managing an unbundled contract isn't worth the potential savings, businesses in industries with thin margins where cost spikes could be damaging, and businesses without dedicated energy management resources.

An unbundled or index contract is typically better for: larger commercial and industrial accounts with dedicated energy managers, businesses with operational flexibility to respond to market price signals, organizations that actively manage their PJM capacity tag and want direct financial benefit from reduction efforts, and sophisticated energy buyers who understand and can manage the risk.

The right rate structure depends on your business's specific financial situation, risk tolerance, operational capabilities, and energy management sophistication. Here's a decision framework.

Start With Your Risk Tolerance

If a 20–30% spike in your energy supply cost would create serious operational or financial problems—if your business operates on thin margins, has limited cash reserves, or has fixed-price customer contracts that make it hard to pass energy cost increases through—a fully bundled fixed rate is almost certainly the right choice. Budget certainty has real financial value when the alternative is financial stress.

Consider Your Energy Management Capabilities

Unbundled and index contracts reward active management. If you don't have the time, expertise, or systems to monitor your energy costs against market conditions and respond appropriately—by managing your PLC tag, participating in demand response, or adjusting operations based on price signals—you're unlikely to capture the potential savings of an unbundled structure. The savings require work to realize.

Discuss with a Knowledgeable Energy Broker

The choice between bundled and unbundled is a genuine strategic decision that benefits from expert guidance. An experienced Illinois energy broker can model the historical cost outcomes of each approach based on your specific load profile and help you understand which structure would have served you better over the past several years. Use that analysis as a guide for your decision going forward.

Illinois Energy Advisors can help you evaluate both structures and determine which is most appropriate for your business. Contact us through our contact page or visit our broker guide page to learn more about how we approach this analysis.