Gas Turbine Fuel Costs: Assessing Long-Term Power Generation Economics

For businesses evaluating long-term power generation investments, gas turbine fuel costs can have a decisive impact on operating budgets and overall project returns. Fuel prices, turbine efficiency, operating hours, and maintenance requirements all shape the cost of electricity over an asset’s lifetime. Understanding how these factors interact helps decision-makers compare technologies, manage financial risk, and select a power solution aligned with their operational and sustainability goals.

The price of the turbine is only the starting point. A machine selected for a factory that runs continuously may look very different from one intended to cover expensive grid hours or provide backup. Before comparing quotations, establish how the plant will actually operate—and what happens when that operating pattern changes.

Start with the cost of a delivered megawatt-hour

A useful first calculation is fuel cost per unit of electricity: multiply the turbine’s heat rate by the delivered fuel price, using compatible units and the same heating-value basis. For example, a heat rate expressed in MMBtu per MWh multiplied by a fuel price in dollars per MMBtu gives a fuel cost in dollars per MWh.

That calculation is simple; getting the inputs right is less so. Heat rate may be quoted on a lower heating value (LHV) or higher heating value (HHV) basis. A fuel contract may use the other basis. Mixing them makes an efficiency comparison unreliable. The same applies to gross and net output: electricity consumed by fuel compressors, cooling equipment and other auxiliaries is not available to the site or for sale.

Use net plant output and net heat rate where possible, and ask suppliers to identify the boundary of each figure. A turbine-only number should not be compared directly with a plant-wide number that includes auxiliaries. Fuel cost is also not the full cost of generation; maintenance, capital expenditure, financing, staffing and other site costs must be considered separately.

Rated efficiency is not the operating profile

A gas turbine quote typically highlights performance at specified conditions and load. The site may spend relatively little time there. Ambient temperature, elevation, inlet and exhaust pressure losses, fuel composition and equipment condition can all affect output or heat rate. A hot afternoon is a particularly inconvenient time to discover that available capacity is below the site’s peak demand.

Part-load performance deserves close attention when production varies by shift or season. A larger unit may appear efficient at its rated output but consume more fuel per net MWh when operated well below that point. Multiple smaller units can offer dispatch flexibility, although they may add equipment, maintenance interfaces and capital cost. Neither configuration is inherently cheaper.

Ask for a performance curve across the expected load range, corrected to the proposed site conditions. Include start-up fuel and any minimum-load or ramping constraints if the plant will cycle. Then model the hours spent at each load rather than applying a single full-load heat rate to the entire year.

Fuel price means more than the commodity quote

The relevant number is the cost of fuel delivered in a condition the turbine can use. Depending on the project, that can include transport, capacity reservations, compression, treatment, storage, metering and applicable taxes or charges. Confirm whether the quoted price is firm, indexed or exposed to changes in transport costs, and whether minimum purchase commitments apply when the plant is idle.

Fuel quality matters as well. Variations in composition, pressure and contaminants can affect the fuel system and operating assumptions. If backup liquid fuel or a different gas supply is part of the resilience plan, verify the required equipment, switching procedure, storage arrangements and performance on each fuel. “Dual-fuel capable” is not a substitute for a site-specific scope.

Run at least a low, central and high delivered-price scenario. Pair each with realistic operating hours: a high fuel price may reduce the hours when self-generation is economical against grid purchases. Holding annual output constant in every scenario can overstate both fuel expenditure and the value of generation.

Consider the value of exhaust heat before choosing a cycle

For a facility with a steady steam or heat demand, a simple-cycle electricity calculation can miss a substantial part of the decision. Recovering exhaust heat for process use can reduce separate boiler fuel consumption. Alternatively, a combined-cycle configuration uses recovered heat to produce additional electricity. The right comparison depends on whether the site needs heat, power or both—and when it needs them.

SINO-QNP’s Steam Turbine offering includes condensing, extraction-condensing and back-pressure configurations relevant to combined-cycle and heat-supply projects. Selection requires more than matching a nameplate capacity: steam pressure, temperature, process demand and cooling arrangements must be assessed together. A back-pressure arrangement, for example, needs a dependable use for its exhaust steam; electricity output and heat delivery are linked.

Avoid crediting recovered heat at its theoretical maximum all year. Use the plant’s hourly or seasonal heat demand, allow for periods when equipment is offline, and establish what fuel or purchased energy the recovered heat actually displaces. Additional heat-recovery equipment also brings capital cost, maintenance and operational complexity.

Maintenance and availability change the fuel equation

Performance can deteriorate between maintenance events. Fouling, wear and changes in clearances may increase heat rate or reduce output, so a lifetime model based only on new-machine performance is optimistic. Ask how the supplier expects performance to change, what cleaning or inspection restores it, and which assumptions are included in any guarantee.

Operating hours are not the only maintenance driver. Frequent starts, load changes and fuel choice can affect inspection intervals and component life. Compare service proposals on the same duty cycle, including planned outages, major components, spare parts and work excluded from the contract. Also price the consequence of unavailability: an industrial site may need to buy grid power, run backup equipment or curtail production.

SINO-QNP brings more than 30 years of turbomachinery experience across design, manufacturing, EPC projects and spare parts supply. For a buyer, the practical question is how those capabilities translate into the proposed project: who supports commissioning, which parts are stocked, and what response arrangements are available at the site.

Make competing bids answer the same questions

Before awarding a contract, issue a common set of assumptions covering ambient conditions, fuel specification, load profile, annual starts, net output and expected service life. Request performance at several loads, a breakdown of auxiliary consumption, maintenance scope and the conditions attached to guarantees. If emissions control or future fuel changes are part of the plan, include their equipment, operating costs and technical limits in the comparison rather than treating them as a later adjustment.

Then test the options using discounted lifetime cash flows as well as cost per net MWh. A lower fuel bill may not repay a higher initial investment at low annual utilization; the opposite may be true for a continuously operated plant. The strongest procurement decision is the one that remains credible when fuel price, dispatch hours and maintenance assumptions move away from the base case.