This document discusses the input-output, heat rate, and incremental cost characteristics of thermal power plants. It defines input-output characteristics as a plot of fuel input versus power output. Heat rate is the ratio of fuel input to energy output and is the slope of the input-output curve. An incremental fuel rate curve plots the incremental fuel rate, or change in input divided by change in output, versus output. The incremental cost curve multiplies incremental fuel rate by fuel cost to determine incremental cost in monetary terms per unit of output. Economic dispatch of power plants aims to minimize total incremental costs while meeting demand.

1. INPUT-OUTPUT , HEAT RATE
CHARACTERISTICS AND INCREMENTAL
COST OF UNITS OF THERMAL POWER
PLANT
SUBMITTED TO SUBMITTED BY
PROF. J. SANDEEP SONI EKLAVYA SHARMA

2. INPUT-OUTPUT CHARACTERISTICS
 Input-Output characteristics is the fundamental curve for a
thermal plant
 It is a plot of the input in British thermal units (Btu) per hour
versus the power output of the plant in MW .

3. INPUT-OUTPUT CHARACTERISTICS

4. HEAT RATE CHARACTERSTICS
 The heat rate is the ratio of fuel input in Btu to energy output
in KWh.
 It is the slope of the input – output curve at any point.
 The reciprocal of heat rate is called fuel efficiency.
 The heat rate curve is a plot of heat rate versus output in MW

5. HEAT RATE CURVE

6. INCREMENTAL FUEL RATE CURVE
 The incremental fuel rate is equal to a small change in input
divided by the corresponding change in output.
 Incremental fuel rate =
∆𝐼𝑁𝑃𝑈𝑇
∆𝑂𝑈𝑇𝑃𝑈𝑇
 The unit is again Btu / KWh. A plot of incremental fuel rate
versus the output

7. INCREMENTAL FUEL RATE CURVE

8. INCREMENTAL COST CURVE
 The incremental cost is the product of incremental fuel rate
and fuel cost (Rs / Btu or $ /Btu).
 The unit of the incremental fuel cost is Rs / MWh or $ /MWh.
 The incremental fuel cost is given by

𝑑𝐹𝑖
𝑑𝑃𝐺𝑖
= bi + 2ci PGi Rs / MWh

9. INCREMENTAL COST CURVE

10. INCREMENTAL COSTS OF UNITS OF
THERMAL POWER PLANT
 The simplest case of economic dispatch is the case when
transmission losses are neglected.
 The model does not consider the system configuration or line
impedances. Since losses are neglected, the total generation is
equal to the total demand PD

11. INCREMENTAL COSTS OF UNITS OF
THERMAL POWER PLANT

12. Thank you