# Economic Decision-Making for Coal Power Flexibility Retrofitting and Compensation in China

^{1}

^{2}

^{3}

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Flexible Operation in a Power System

## 3. Flexibility Provided by Rapid Ramp Rate

#### 3.1. Model for Flexibility Potential Provided by Rapid Ramp Rate Retrofitting

_{tu}.

#### 3.2. Ramp Rate Retrofitting Scenario and Flexibility Potential

_{up}of ramp rate retrofitting can be defined as:

## 4. Flexibility Provided by Peak Shaving Depth Retrofitting

#### 4.1. Model for Flexibility Potential Provided by Peak Shaving Depth Retrofitting

#### 4.2. Flexibility Potential for Peak Shaving Depth Retrofitting

#### 4.2.1. Unified Downward Ramp Rate and Five Different Depth

_{d1}are also shown in Table 5.

#### 4.2.2. Same Depth and Four Different Downward Ramp Rates

- ${r}_{d2}=[4\%,5\%,6\%,7\%]\cdot {P}_{n}$ for 300 MW unit; ${r}_{d2}=[5\%,6\%,7\%,8\%]\cdot {P}_{n}$ for 600 MW unit;
- ${r}_{d2}=[6\%,7\%,8\%,9\%]\cdot {P}_{n}$ for 700 MW unit; ${r}_{d2}=[7\%,8\%,9\%,10\%]\cdot {P}_{n}$ for 900 MW unit;
- ${r}_{d2}=[8\%,9\%,10\%,11\%]\cdot {P}_{n}$ for 900 MW unit.

## 5. Economic Decision-Making for Coal Power Flexibility Retrofitting

#### 5.1. Fixed Cost of Peak Shaving Depth Retrofitting

#### 5.2. Variable Cost-Generation Loss Cost from Peak Shaving Depth Retrofitting

^{6}yuan.

#### 5.3 Revenue from Peak Shaving Depth Operation

#### 5.4. Flexible Electricity Marginal Cost and Marginal Revenue

#### 5.5. Analysis of Characteristic Roots in Two Scenarios

- (1)
- If there is a characteristic root in every piecewise range of $H$, the peak shaving retrofitting decision will be ‘yes’. As the actual running depth is less than or equal to the calculated $H*$ in every piecewise range of $H$, the margin revenue can cover the margin cost, and the compensation standard is rational and the plant operators are willing to carry out coal power flexibility retrofitting.
- (2)
- If there are no roots in every piecewise range of $H$ and the calculated $H*$ is bigger than every piecewise range of $H$, then the peak shaving retrofitting decision will be ‘yes’ and the compensation standard will be high enough for the plant operators to carry out coal power flexibility retrofitting.
- (3)
- If there are no roots in every piecewise range of $H$ and the calculated $H*$ is less than every piecewise range of $H$, then the peak shaving retrofitting decision will be ‘no’ and the compensation standard will be too low to carry out coal power flexibility retrofitting.

- (1)
- When the times of peak shaving operation are equal to 100, this compensation standard is not enough for a depth deeper than 0.52.
- (2)
- When the times of peak shaving operation are equal to 300, this compensation is good enough for carrying out peak shaving operation.

## 6. Conclusions

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## Abbreviation

$(A/P,i,yr)$ | capital recovery factor |

$C$ | total cost for one time of peak shaving |

${C}_{f}$ | total fixed cost for coal power peak shaving retrofitting |

${C}_{af}$ | annual fixed cost for coal power peak shaving retrofitting |

${C}_{of}$ | average fixed cost for one time of peak shaving |

${C}_{v}$ | variable cost for one time of peak shaving |

$E$ | flexible electricity for one time peak shaving operation |

${E}_{tu}$ | upward flexible electricity for rapid ramp up |

${E}_{td}$ | downward flexible electricity for peak shaving operation |

$\Delta {E}_{tu}$ | increased upward flexible electricity corresponding to two adjacent scenarios in 15 min |

$\Delta {E}_{tdp}$ | increased downward flexible electricity for two adjacent retrofitted depth within 15 min |

$\Delta {E}_{td}$ | increased downward flexible electricity for two adjacent retrofitted ramp rate within 15 min |

${e}_{peak}$ | peak shaving elasticity coefficient |

${e}_{down}$ | downward elastic coefficient |

${e}_{up}$ | upward elastic coefficient |

${f}_{1}(H)$ | per unit generation cost before retrofitted |

${f}_{2}(H)$ | per unit generation cost after retrofitted |

$H$ | peak shaving depth |

$H*$ | characteristic roots for $MC=MR$ |

MC | margin cost of peak shaving retrofitting |

MR | margin revenue of peak shaving retrofitting |

$n$ | total times of annual peak shaving operation |

${P}_{u}$ | initial output power before the unit responses to rapid ramp |

${P}_{n}$ | rated output of coal power unit |

$P$ | initial output power before response to peak shaving operation |

$\Delta {P}_{up}$ | increased output power of two retrofitted ramp rate scenarios |

${P}_{d1}$ | minimum technical output before depth retrofitted |

${P}_{d2}$ | minimum technical output after depth retrofitted |

$\Delta {P}_{d2}$ | increased retrofitted minimum output power |

$R$ | total revenue of one time of peak shaving |

${r}_{u1}$ | upward ramp rate before retrofitted |

${r}_{u2}$ | upward ramp rate after retrofitted |

$\Delta {r}_{d2}$ | increased downward ramp rate of two adjacent retrofitted ramp rate |

$\Delta {r}_{u}$ | increased upward ramp rate of two adjacent retrofitted ramp rate |

${r}_{d1}$ | downward ramp rate before retrofitted |

${r}_{d2}$ | downward ramp rate after retrofitted |

${r}_{B}$ | compensation standard of per megawatt hour electricity in basic scenario |

${r}_{P}$ | compensation standard of per megawatt hour electricity in policy scenario |

$T$ | running time of peak shaving operation |

$t$ | response time of rapidly ramp up and down |

${t}_{u2}$ | running time arriving at ${P}_{N}$ before retrofitted in upward ramp rate retrofitting |

${t}_{u1}$ | running time arriving at ${P}_{N}$ after retrofitted in upward ramp rate retrofitting |

${t}_{d1}$ | running time to reach ${P}_{d2}$ in peak shaving retrofitting |

${t}_{d2}$ | running time to reach ${P}_{d1}$ in peak shaving retrofitting |

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Retrofitted Target | Retrofitting Process | |
---|---|---|

1 | The minimum output power can be reduced to 15–20% of the rated power. | Ensure: A. The stable combustion of the boiler B. The proper working of the environmental protection devices, such as desulfurizer. |

2 | The maximum ramp rate can be increased to 4–11% of the rated power. | Optimize the steam outlet valve of the steam turbine or raise the fuel calorific value of the boiler. |

3 | Different thermal state of units have different start–stop times. Gas power units: 0.1–1 h Coal power units: 2–7 h | Optimize dispatching management measures. Control the inlet temperature and speed of the boiler. Reduce the start–stop time of the boiler and the steam engine. |

4 | CHP units are firstly used for heating in the cold winter, and the by-product is electricity. Therefore the amount of electricity depends on heat amount. Make heat and electricity independent. | Add heat storage tanks for CHP units. When the power demand in the grid is low, the heat from the CHP units will be stored in heat storage tanks; and once power demand is high in the grid, the heat will be reused to generate electricity. |

5 | Replace fossil fuel combustion equipment with biomass fuels or peat. | Boiler reformation, improve the thermal efficiency and heat utilization rate of boilers. |

**Table 2.**Conventional generator parameter list [32].

Node-Unit | ${\mathit{P}}_{\mathbf{max}}/\mathit{M}\mathit{W}$ | ${\mathit{P}}_{\mathbf{min}}/\mathit{M}\mathit{W}$ | $\mathit{R}\mathit{a}\mathit{m}\mathit{p}\text{-}\mathit{r}\mathit{a}\mathit{t}{\mathit{e}}_{\mathbf{max}}/\mathit{M}\mathit{W}\cdot {\mathbf{min}}^{-1}$ |
---|---|---|---|

30-1 | 350 | 100 | 3 |

31-2 | 1145 | 600 | 7.4 |

32-3 | 750 | 250 | 4.2 |

33-4 | 732 | 250 | 4.2 |

34-5 | 608 | 250 | 3.5 |

35-6 | 750 | 250 | 4.2 |

36-7 | 660 | 250 | 3.5 |

37-8 | 640 | 250 | 3.3 |

38-9 | 930 | 250 | 5.3 |

39-10 | 1100 | 600 | 6 |

Node-unit | S1 | S2 | S3 | S4 | S5 |
---|---|---|---|---|---|

30-1 | 4% | 5% | 6% | 7% | 8% |

14 | 17.5 | 21 | 24.5 | 28 | |

31-2 | 8% | 9% | 10% | 11% | 12% |

91.6 | 103.1 | 114.5 | 126 | 137.4 | |

32-3 | 6% | 7% | 8% | 9% | 10% |

45 | 52.5 | 60 | 67.5 | 70 | |

33-4 | 6% | 7% | 8% | 9% | 10% |

43.9 | 51.2 | 58.6 | 65.9 | 73.2 | |

34-5 | 5% | 6% | 7% | 8% | 9% |

30.4 | 36.5 | 42.6 | 48.6 | 54.7 | |

35-6 | 6% | 7% | 8% | 9% | 10% |

45.0 | 52.5 | 60.0 | 67.5 | 75.0 | |

36-7 | 5% | 6% | 7% | 8% | 9% |

33.0 | 39.6 | 46.2 | 52.8 | 59.4 | |

37-8 | 5% | 6% | 7% | 8% | 9% |

32.0 | 38.4 | 44.8 | 51.2 | 57.6 | |

38-9 | 7% | 8% | 9% | 10% | 11% |

65.1 | 74.4 | 83.7 | 93.0 | 102.3 | |

39-10 | 8% | 9% | 10% | 11% | 12% |

88 | 99 | 110 | 121 | 132 |

Unit | S2-S1 | S3-S2 | S4-S3 | S5-S4 | Optimized Range of Ramp Rate |
---|---|---|---|---|---|

30-1 | 5.14 | 0.46 | 0.49 | 0.46 | 4–5% |

31-2 | 0.26 | 0.21 | 0.17 | 0.14 | 8–9% |

32-3 | 0.43 | 0.47 | 0.48 | 0.40 | 7–9% |

33-4 | 0.46 | 0.48 | 0.46 | 0.40 | 7–8% |

34-5 | 0.46 | 0.48 | 0.46 | 0.41 | 6–7% |

35-6 | 0.43 | 0.47 | 0.48 | 0.40 | 7–9% |

36-7 | 0.47 | 0.47 | 0.47 | 0.44 | 5–7% |

37-8 | 0.39 | 0.47 | 0.47 | 0.44 | 6–8% |

38-9 | 0.46 | 0.47 | 0.46 | 0.41 | 7–9% |

39-10 | 0.24 | 0.18 | 0.16 | 0.14 | 8–9% |

Node-Unit | ${\mathit{r}}_{\mathit{d}1}/\mathit{M}\mathit{W}\cdot {\mathbf{min}}^{-1}$ | ${\mathit{r}}_{\mathit{d}2}/\mathit{M}\mathit{W}\cdot {\mathbf{min}}^{-1}$ | ${\mathit{t}}_{\mathit{d}1}/\mathbf{min}$ (Running Time for Reaching the Target Depth) | ||||
---|---|---|---|---|---|---|---|

$35\%{\mathit{P}}_{\mathit{n}}$ | $30\%{\mathit{P}}_{\mathit{n}}$ | $25\%{\mathit{P}}_{\mathit{n}}$ | $20\%{\mathit{P}}_{\mathit{n}}$ | $15\%{\mathit{P}}_{\mathit{n}}$ | |||

30-1 | 3 | $4\%{P}_{n}$ | 18 * | 18 * | 19 * | 20 * | 20 * |

31-2 | 7.4 | $8\%{P}_{n}$ | 8 | 9 | 9 | 10 | 11 |

32-3 | 4.2 | $6\%{P}_{n}$ | 11 | 12 | 13 | 13 | 14 |

33-4 | 4.2 | $6\%{P}_{n}$ | 11 | 12 | 13 | 13 | 14 |

34-5 | 3.5 | $5\%{P}_{n}$ | 13 | 14 | 14 | 16 * | 17 * |

35-6 | 4.2 | $6\%{P}_{n}$ | 11 | 12 | 13 | 13 | 14 |

36-7 | 3.5 | $4\%{P}_{n}$ | 13 | 14 | 15 | 16 * | 21 * |

37-8 | 3.3 | $4\%{P}_{n}$ | 13 | 14 | 15 | 16 * | 21 * |

38-9 | 5.3 | $7\%{P}_{n}$ | 10 | 10 | 11 | 11 | 12 |

39-10 | 6 | $8\%{P}_{n}$ | 8 | 9 | 9 | 10 | 11 |

Node-Unit | A | B | C | D | Optimized Depth |
---|---|---|---|---|---|

31-2 | 0.36 | 0.28 | 0.44 | 0.04 | C |

32-3 | 0.36 | 0.18 | 0.53 | 0.06 | C |

33-4 | 0.36 | 0.16 | 0.55 | 0.06 | C |

35-6 | 0.36 | 0.18 | 0.53 | 0.06 | C |

38-9 | 0.36 | 0.28 | 0.43 | 0.05 | C |

39-10 | 0.36 | 0.21 | 0.51 | 0.04 | C |

_{n}; B represents the range of 25–30%P

_{n}; C represents the range of 20–25%P

_{n}; D represents the range of 15–20%P

_{n}.

Node-Unit | S_{d1} | S_{d2} | S_{d3} | S_{d4} |
---|---|---|---|---|

30-1 | $4\%{P}_{n},20\%{P}_{n}$ | $5\%{P}_{n},20\%{P}_{n}$ | $6\%{P}_{n},20\%{P}_{n}$ | $7\%{P}_{n},20\%{P}_{n}$ |

31-2 | $8\%{P}_{n},20\%{P}_{n}$ | $9\%{P}_{n},20\%{P}_{n}$ | $10\%{P}_{n},20\%{P}_{n}$ | $11\%{P}_{n},20\%{P}_{n}$ |

32-3 | $6\%{P}_{n},20\%{P}_{n}$ | $7\%{P}_{n},20\%{P}_{n}$ | $8\%{P}_{n},20\%{P}_{n}$ | $9\%{P}_{n},20\%{P}_{n}$ |

33-4 | $6\%{P}_{n},20\%{P}_{n}$ | $7\%{P}_{n},20\%{P}_{n}$ | $8\%{P}_{n},20\%{P}_{n}$ | $9\%{P}_{n},20\%{P}_{n}$ |

34-5 | $5\%{P}_{n},20\%{P}_{n}$ | $6\%{P}_{n},20\%{P}_{n}$ | $7\%{P}_{n},20\%{P}_{n}$ | $8\%{P}_{n},20\%{P}_{n}$ |

35-6 | $6\%{P}_{n},20\%{P}_{n}$ | $7\%{P}_{n},20\%{P}_{n}$ | $8\%{P}_{n},20\%{P}_{n}$ | $9\%{P}_{n},20\%{P}_{n}$ |

36-7 | $5\%{P}_{n},20\%{P}_{n}$ | $6\%{P}_{n},20\%{P}_{n}$ | $7\%{P}_{n},20\%{P}_{n}$ | $8\%{P}_{n},20\%{P}_{n}$ |

37-8 | $5\%{P}_{n},20\%{P}_{n}$ | $6\%{P}_{n},20\%{P}_{n}$ | $7\%{P}_{n},20\%{P}_{n}$ | $8\%{P}_{n},20\%{P}_{n}$ |

38-9 | $7\%{P}_{n},20\%{P}_{n}$ | $8\%{P}_{n},20\%{P}_{n}$ | $9\%{P}_{n},20\%{P}_{n}$ | $10\%{P}_{n},20\%{P}_{n}$ |

39-10 | $8\%{P}_{n},20\%{P}_{n}$ | $9\%{P}_{n},20\%{P}_{n}$ | $10\%{P}_{n},20\%{P}_{n}$ | $11\%{P}_{n},20\%{P}_{n}$ |

Unit | ${\mathit{t}}_{\mathit{d}1}/\mathbf{min}$ under Different ${\mathit{r}}_{\mathit{s}\mathit{d}2}/\mathbf{MW}\cdot {\mathbf{min}}^{-1}$ Reaching the Target of $20\%{\mathit{P}}_{\mathit{n}}$ | ||||
---|---|---|---|---|---|

S_{d1} | S_{d2} | S_{d3} | S_{d4} | ||

30-1 | ${r}_{sd2}$ | 14.0 | 17.5 | 21.0 | 24.5 |

${t}_{d1}$ | 20.0 * | 16.0* | 13.3 | 11.4 | |

31-2 | ${r}_{sd2}$ | 91.6 | 103.1 | 114.5 | 126.0 |

${t}_{d1}$ | 10.0 | 8.9 | 8.0 | 7.3 | |

32-3 | ${r}_{sd2}$ | 45.0 | 52.5 | 60.0 | 67.5 |

${t}_{d1}$ | 13.3 | 11.4 | 10.0 | 8.9 | |

33-4 | ${r}_{sd2}$ | 43.9 | 51.2 | 58.6 | 65.9 |

${t}_{d1}$ | 13.3 | 11.4 | 10.0 | 8.9 | |

34-5 | ${r}_{sd2}$ | 30.4 | 36.5 | 42.6 | 48.6 |

${t}_{d1}$ | 16.0 * | 13.3 | 11.4 | 10.0 | |

35-6 | ${r}_{sd2}$ | 45.0 | 52.5 | 60.0 | 67.5 |

${t}_{d1}$ | 13.3 | 11.4 | 10.0 | 8.9 | |

36-7 | ${r}_{sd2}$ | 33.0 | 39.6 | 46.2 | 52.8 |

${t}_{d1}$ | 16.0 * | 13.3 | 11.4 | 10.0 | |

37-8 | ${r}_{sd2}$ | 32.0 | 38.4 | 44.8 | 51.2 |

${t}_{d1}$ | 16.0 * | 13.3 | 11.4 | 10.0 | |

38-9 | ${r}_{sd2}$ | 65.1 | 74.4 | 83.7 | 93.0 |

${t}_{d1}$ | 11.4 | 10.0 | 8.9 | 8.0 | |

39-10 | ${r}_{sd2}$ | 88.0 | 99.0 | 110.0 | 121.0 |

${t}_{d1}$ | 10.0 | 8.9 | 8.0 | 7.3 |

Node-Unit | S_{d2}-S_{d1} | S_{d3}-S_{d2} | S_{d4}-S_{d3} | Optimized Downward Ramp Rate |
---|---|---|---|---|

30-1 | 1.89 | 21.03 | 0.11 | 5–6% |

31-2 | 0.07 | 0.06 | 0.05 | 8–9% |

32-3 | 0.12 | 0.09 | 0.08 | 6–7% |

33-4 | 0.12 | 0.11 | 0.07 | 6–7% |

34-5 | 20.61 | 0.13 | 0.08 | 5–6% |

35-6 | 0.12 | 0.09 | 0.08 | 7–8% |

36-7 | 20.53 | 0.14 | 0.09 | 5–6% |

37-8 | 20.52 | 0.13 | 0.09 | 5–6% |

38-9 | 0.10 | 0.08 | 0.06 | 7–8% |

39-10 | 0.07 | 0.06 | 0.05 | 8–9% |

Depth ($\mathit{H}$) | 0.55 | 0.60 | 0.65 | 0.70 | 0.75 | 0.80 | 0.85 |
---|---|---|---|---|---|---|---|

Per Cost (${10}^{3}$ yuan/MW) | 50 | 75 | 100 | 125 | 150 | 175 | 200 |

${C}_{f}$ (${10}^{6}$ yuan) | 1.5 | 4.5 | 9.0 | 15.0 | 22.5 | 31.5 | 42.0 |

Before Retrofitting | After Retrofitting | ||||||
---|---|---|---|---|---|---|---|

P/MW | Depth | kg/MWh | yuan/MWh | P/MW | Depth | kg/MWh | yuan/MWh |

600 | 0 | 299.6 | 179.8 | 600 | 0 | 299.6 | 179.8 |

550 | 0.08 | 319.7 | 191.4 | 550 | 0.08 | 320.7 | 192.4 |

500 | 0.16 | 339.4 | 203.6 | 500 | 0.16 | 340.8 | 204.5 |

450 | 0.25 | 359.8 | 215.9 | 450 | 0.25 | 360.9 | 216.5 |

400 | 0.33 | 377.6 | 226.6 | 400 | 0.33 | 380.0 | 228.0 |

350 | 0.42 | 389.0 | 233.4 | 350 | 0.42 | 395.1 | 237.1 |

300 | 0.50 | 399.3 | 239.6 | 300 | 0.50 | 414.2 | 248.5 |

- | - | - | - | 250 | 0.58 | 433.3 | 260.0 |

- | - | - | - | 200 | 0.67 | 452.4 | 271.4 |

- | - | - | - | 150 | 0.75 | 463.0 | 277.8 |

- | - | - | - | 90 | 0.85 | 472.4 | 283.4 |

Depth | 0–0.50 | 0.50–0.60 | 0.60–0.70 | 0.70–0.85 |

${r}_{\mathrm{B}}$ | 0 | 0.0004 | 0.0006 | 0.0008 |

Depth | 0–0.40 | 0.40–0.85 | ||

${r}_{P}$ | 0.0004 | 0.001 | 0.001 | 0.001 |

$H$ | (0.50, 0.60] | (0.60, 0.70] | (0.70, 0.85] |

${r}_{B}(H)$ | 0.0004 | 0.0006 | 0.0008 |

$n$ | (55, 305] | (203, 355] | (277, 402] |

Total annual peak shaving running hours $n\cdot T$ | |||

$T=0.25\text{\hspace{0.17em}}\mathrm{h}$ | (14, 76] | (51, 89] | (69, 101] |

$T=0.50\text{\hspace{0.17em}}\mathrm{h}$ | (28, 152] | (102, 198] | (138, 201] |

$T=0.75\text{\hspace{0.17em}}\mathrm{h}$ | (42, 228] | (153, 267] | (207, 303] |

$T=1.0\text{\hspace{0.17em}}\mathrm{h}$ | (55, 305] | (203, 355] | (277, 402] |

$H$ | (0.50, 0.60] | (0.60, 0.70] | (0.70, 0.85] |

${r}_{P}(H)$ | 0.001 | ||

$n$ | (22, 322] | ||

Total annual peak shaving running hours $n\cdot T$ | |||

T = 0.25 h | (4, 81] | ||

T = 0.50 h | (8, 162] | ||

T = 0.75 h | (12, 243] | ||

T = 1.0 h | (22, 322] |

Items | Jilin Province | |
---|---|---|

Curtailed wind power (GWh) | 2900 | |

Total coal power flexibility retrofitting capacity(GW) | 13.30 | |

Peak shaving operation hours (h) | the depth from 0.50 to 0.60 | 2180 |

the depth from 0.5 to 0.70 | 1090 | |

the depth from 0.50 to 0.85 | 727 |

$H$ | (0.50, 0.60] | (0.60, 0.70] | (0.70, 0.85] | ||

${r}_{B}(H)$ | 0.0004 | 0.0006 | 0.0008 | ||

$H*$ | $n=100$ | 0.5182 | 0.5382 | 0.5582 | |

Decision and compensation standard | Yes, enough for $\le H*$ | No, not enough | No, not enough | ||

$n=300$ | 0.5982 | 0.6582 | 0.7182 | ||

Decision and compensation standard | Yes, enough for $\le H*$ | Yes, enough for $\le H*$ | Yes, enough for $\le H*$ | ||

$n=500$ | 0.6782 | 0.7782 | 0.8782 | ||

Decision and compensation standard | Yes, high | Yes, high | Yes, high | ||

${r}_{P}(H)$ | 0.001 | ||||

$H*$, Decision and compensation standard | $n=100$ | 0.5782, Yes, enough for $\le H*$ | |||

$n=300$ | 0.7782, Yes, enough for $\le H*$ | ||||

$n=500$ | 0.9782, Yes, high compensation standard |

Conclusions | Determinants | |
---|---|---|

1 | Upward ramp rate | Upward elastic coefficient |

Downward ramp rate | Downward elastic coefficient | |

Peak shaving depth | Peak shaving elastic coefficient | |

2 | Economic decision-making | Depth, compensation standard, times |

Compensation standard | Depth, times |

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Na, C.; Yuan, J.; Zhu, Y.; Xue, L.
Economic Decision-Making for Coal Power Flexibility Retrofitting and Compensation in China. *Sustainability* **2018**, *10*, 348.
https://doi.org/10.3390/su10020348

**AMA Style**

Na C, Yuan J, Zhu Y, Xue L.
Economic Decision-Making for Coal Power Flexibility Retrofitting and Compensation in China. *Sustainability*. 2018; 10(2):348.
https://doi.org/10.3390/su10020348

**Chicago/Turabian Style**

Na, Chunning, Jiahai Yuan, Yuhong Zhu, and Li Xue.
2018. "Economic Decision-Making for Coal Power Flexibility Retrofitting and Compensation in China" *Sustainability* 10, no. 2: 348.
https://doi.org/10.3390/su10020348