Optimum Schedule Economic Dispatch Calculator

Balance demand, losses, and generator limits with clear dispatch math. Export results for records now. Review lambda, costs, and savings before production planning decisions.

Calculator Inputs

System Case

Unit 1

Unit 2

Unit 3

Unit 4

Unit 5

Example Data Table

Generator a b c Min MW Max MW Current MW Ramp MW
Unit 15005.300.004050250120999
Unit 24005.500.006080220120999
Unit 32005.800.00904015080999
Unit 43006.000.00703016080999
Unit 52505.700.005060200100999

Formula Used

The quadratic fuel cost model is:

Fi(Pi) = ai + biPi + ciPi2

The incremental cost condition for free running units is:

λ = bi + 2ciPi

So the scheduled output is:

Pi = (λ - bi) / (2ci)

The calculator clamps each output between its effective minimum and maximum. Effective limits include ramp allowance when entered. The target equals demand plus reserve plus estimated loss allowance.

How to Use This Calculator

Enter system demand in MW. Add reserve and estimated losses when needed.

Enter each generator cost curve. Use positive quadratic coefficients.

Add minimum and maximum MW limits for every online unit.

Use current MW and ramp allowance when short-term movement is limited.

Uncheck any generator that is not available for dispatch.

Press calculate to show the optimum schedule above the form.

Use CSV or PDF buttons to export the current calculation.

Economic Dispatch Planning for Balanced Generation

Economic dispatch helps operators choose the lowest cost mix of online generators. Each unit has its own fuel curve. The curve usually rises as output increases. A good schedule does not simply divide demand equally. It compares incremental costs and respects each operating limit. This approach is useful for thermal units, teaching examples, and screening studies.

Why Lambda Matters

The lambda value is the common incremental cost used by unconstrained units. When a unit is inside its minimum and maximum range, its marginal cost should match lambda. If the unit reaches a boundary, the calculator locks it there. The remaining demand is then shared by flexible units. The lambda is found by repeated balancing. The process keeps adjusting output until supply is close to the required target.

Advanced Inputs

This page accepts fixed cost, linear cost, quadratic cost, unit limits, current output, ramp allowance, demand, reserve, and estimated losses. These inputs support planning cases with practical restrictions. Ramp data is optional. When it is used, the available range is narrowed around the present output. A reserve entry can represent extra scheduled headroom. The loss entry adds a simple demand allowance. It is not a full power flow study.

Interpreting Results

The result table shows scheduled megawatts, unit cost, incremental cost, and active bounds. A lower total cost means the schedule uses cheaper units more effectively. Savings compare the optimized plan with a simple bounded sharing case. The comparison is only a planning reference, not a market settlement. Review each unit row before using the output. A generator at a limit may need attention, fuel review, or a different commitment choice.

Good Practice

Use realistic fuel coefficients. Check whether all generators are available. Review warnings about infeasible demand. If demand is above total capacity, the shortage is shown. If demand is below total minimum output, oversupply is shown. Operators should also consider security limits, emissions, start costs, and network studies.

Planning Context

Economic dispatch is one part of an operating workflow. Unit commitment decides which machines run. Dispatch decides how much each online machine should produce. Real systems may include prohibited zones, valve point effects, hydro limits, batteries, renewable forecasts, and transmission constraints. Use this calculator as a transparent planning model. Then confirm the schedule with approved engineering tools and operating rules.

FAQs

What is economic dispatch?

Economic dispatch finds the lowest cost output for online generators while meeting demand and respecting operating limits.

What does lambda mean?

Lambda is the common incremental cost for generators that are not fixed at minimum or maximum limits.

Why can a unit stay at a limit?

A unit stays at a limit when the unconstrained economic output would fall outside its allowed MW range.

Does this include transmission losses?

It includes a simple percentage loss allowance. It does not solve a detailed network loss or power flow model.

Can I use ramp limits?

Yes. Enter current MW and ramp allowance. The calculator narrows the effective operating range for that case.

What if demand is too high?

The calculator schedules available maximum output and reports the remaining shortage against the requested target.

What if demand is too low?

The calculator schedules minimum online output and reports oversupply when the target is below combined minimum generation.

Is this suitable for final operation?

Use it for planning and education. Final operation should also review security limits, contracts, emissions, reliability rules, and approved tools.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.