Economic Analysis of Solid Oxide Fuel Cell Systems Utilizing Natural Gas as Fuel

Abstract

Solid oxide fuel cell power generation systems are devices that utilize solid electrolytes to transfer ions for electrochemical energy conversion. A wide range of gases can be used as fuel gas, including hydrogen, natural gas, and carbon monoxide. Considering the high cost of pure hydrogen, hydrogen production from natural gas reforming has become a hot research area. In this study, the 4F-LCA method was employed to construct an evaluation framework, with a particular emphasis on the cost analysis of solid oxide fuel cell power generation systems, and uses a bottom-up approach to build a system economic analysis model to visualize the major costs involved in the system. An economic benefit analysis and sensitivity analysis were carried out for the 2 kW natural gas solid oxide fuel cell as a case by taking the financial net present value (NPV), internal rate of return (IRR) and payback period into account. In this study, the investment cost and payback period of a 2 kW solid oxide fuel cell system are obtained, which can provide a reference for the project construction and operation of solid oxide fuel cell systems.

1. Introduction

The overconsumption of fossil energy and the continued increase in global greenhouse gas emissions have reached a new peak. In response, there is an opportunity for the diversified application of green renewable energy to address these challenges. The National Development and Reform Commission. China maps 2021–2035 plan on hydrogen energy development, which was promulgated by China in 2022, clarifies the strategic positioning of hydrogen energy in China’s green and low-carbon energy transition [1]. Hydrogen is a high-calorific-value clean energy source that can be combusted to produce thermal and kinetic energy, as well as electrical and thermal energy through fuel cells (FCs) [2]. A solid oxide fuel cell (SOFC) system is based on ceramic electrolyte and utilizes gas-reforming hydrogen for electrochemical energy conversion. It operates at temperatures ranging from 600 to 1000 °C [3] and boasts significantly higher power generation efficiency compared to other FCs [4]. The potential applications of SOFC systems include distributed power plants, commercial buildings, cogeneration systems, and offshore marine auxiliary power units [5,6,7,8]. While the commercialization of SOFC power generation systems in foreign nations has reached maturity, domestic technology still faces challenges [8]. Drawing on the existing research foundation and foreign results [9,10,11], an economic analysis of the SOFC system combined with practical cases will provide a theoretical framework for company cost reduction, as well as certain economic, environmental, and social benefits. This work outlines the primary production workflow for SOFC systems, establishes a model for the economic flow analysis of the system [12,13], and illustrates the cost analysis of economic evaluation indicators while considering factors affecting performance such as sensitivity and economic benefit analyses. The study focuses on a 2 kW SOFC system powered by pipeline natural gas. Additionally, it determines key economic elements while utilizing China’s carbon trading scheme to calculate greenhouse gas emission reductions’ impact on the main evaluation indexes.

2. Solid Oxide Fuel Cell System

The research object of this paper is a newly made SOFC power generation system with a constant output power of 2 kW (Wuxi, China). This product mainly includes the following processes:

• Production of ancillary equipment which includes choosing various steel types and forging in accordance with the design device’s dimensions. The reformer, desulphurization tanks, static mixing tanks, and other components were designed by the project unit independently;
• Pre-treatment of the fuel gas, the desulphurization of the raw gas using adsorbents;
• Single cell production, a complex manufacturing process that can be broken down into the following stages: powder treatment, paste printing, and monomer sintering [14];
• Cell stack production, in which the cut cell monomers are assembled with bipolar plates and seals;
• Operation of the cell stack system, in which the output power of the stack and the tail gas emission are analyzed.

Prior to the study, we conducted a literature review (

Table 1. Economic analysis of the SOFC—literature survey.

	Sizes	Form	Index
Andrea L. Facci [15]	25 kW /40 kW	SOFC-based CHCP plant	Cost minimization	PEC minimization	Payback period time	-
Moein Shamoushaki [16]	-	SOFC-GT	Cost per unit of time	fuel cost rate	Exergy destruction cost	Payback period time
R. Napoli [17]	1 kW	PEMFC and SOFC micro-CHP fuel cell systems	Net present value	-	-	-
Mehdi Aminyavari [18]	-	SOFC-GT hybrid power plant	Cost per unit of time	The unit cost of fuel	-	-
A Khandkar [19]	25 kW	Natural gas-fueled SOFC power system	Total capital cost	Operating cost	-	-
Ettore Bompard [20]	5 kW	High-temperature SOFC systems	Net present value	Internal Rate of Return	-	-
Mousa Meratizaman [21]	11–42.9 kW	SOFC-GT	Annualized capital/replacement/maintenance/operating cost	Net present value	Levelized cost of product	-
Valentina Zaccaria [22]	330 kW	SOFC-GT	Payback Period	Net Present Value	Internal Rate of Return	-
Khalid Al-Khori [23]	20 MW	Combined steam and power system with a SOFC unit	Net present value	Internal Rate of Return	Return of Investment	-
Beneta Eisavi [24]	-	SOFC-based hybrid systems	Total cost	Annual levelized capital investment	The capital recovery factor	-

) of SOFC life cycle cost assessments [15,16,17,18,19,20,21,22,23,24]. In the past few decades, the economic analysis of SOFCs has focused on the thermal economic research of SOFC and hybrid power systems, but seldom on life cycle cost and the profit analysis of the market potential. The team of Andrea L. Facci [15] used two strategies of minimum cost control and minimum PEC control to carry out 25 kW and 40 kW SOFC-based CHCP plants’ economic potential and analyzed three SOFC cost scenarios. The team of Moein Shamoushaki [16] studied the sensitivity analysis of change in objective functions with regard to the SOFC-GT fuel unit cost, and their economic indexes were cost per unit of time, fuel cost rate, exergy destruction cost, and payback period time. The team of R. Napoli [17] conducted economic analysis by comparing the net present value of 1 kW PEMFC and SOFC systems. The annualized cost, net present value, internal rate of return, and payback period time were mostly used in different sizes of high-power SOFC-GT systems by the researchers, Mousa Meratizaman [21], Valentina Zaccaria [22], Khalid Al-Khori [23], and Beneta Eisavi [24]. Similar to Ettore Bompard’s research [20] on 5 kW household systems, we aimed to study the economic features of the newly made 2 kW system for residential application.

3. Materials and Methods

In this study, the 4F-LCA methodology [25] was applied to build an evaluation framework and focus on the economic flow (Figure 1).

The whole system consumption cost of producing an SOFC system mainly includes the raw material input and pretreatment cost, initial investment in production cell equipment, plant operation cost, equipment maintenance cost, and labour cost, and the cost data were obtained through conducting questionnaire surveys with business managers.

3.1. Goal and Scope

The system economic flow analysis model is shown in Figure 2. In this study, the economic flow analysis adopted a bottom-up method, starting from raw material, equipment, land, labour, and utility capital inputs, selecting the appropriate economic indicators for evaluation.

3.2. Life Cycle Cost Inventory

3.2.1. Relevant Data Collection

The data collection related to promotion is based on the industry benchmark and product production status. Decided by the company’s senior leaders, the following provided data can be used for reference.

• Implementation schedule: the construction period is 3 years.
• Funding source: the fixed asset investment funding budget is totally CNY 3.3560 million.
• Depreciation of fixed assets and amortization of intangible and current assets: the depreciation life of fixed assets is 10 years, and the residual value rate is 5.0%; the residual value of intangible and current assets is 0.
• The industry benchmark return is 10%.
• The expected selling price of the system is set at around CNY 80,000 per piece.

3.2.2. Cost Estimation

The initial investment cost of the equipment includes the cost of fixed assets, intangible assets, and deferred assets The operation period is 10 years, with an annual interest rate of 10%, and the depreciation period of fixed assets is also 10 years, with a residual value rate of 5.0%.

Table 2. Main cost data.

Number	Project	Value/CNY Million	Operating Period /CNY Million·Year−1	Salvage Value /CNY Million
1	Fixed assets	335.60	54.61	16.78
2	Intangible assets and deferred assets	33.56	5.46	0.00
3	Money in circulation	300.00	0.00	0.00
4	Land use cost	30.00	0.00	0.00
Total		699.16	60.07	16.78

shows the main data of the economic analysis obtained from the calculation.

Table 3. Annual expenditure.

Categories	Cost		Categories	Cost
Natural gas	CNY million·m3	0.00037	Powder j	CNY million·cylinders−1	0.0087
	Year/m3	6363.74		cylinders	88
N2	CNY million·cylinders−1	0.006	Catalysts	CNY million·kg−1	0.06
	cylinders	10		kg	5
Complementary facility	Material cost/ CNY million	110.4	Purified water	CNY million·barrel−1	0.0035
Stack	Material cost/ CNY million	120.96		barrel	256
	Coating cost/ CNY million	178.56	Print Cutting	CNY million	178.56
Powder a	CNY million·kg−1	0.096	Water	CNY million·t−1	0.00022
	kg	21		t	821.25
Powder b	CNY million·kg−1	0.0735	Desulphurization	CNY million·kg−1	0.028
	kg	148		kg	3
Powder c	CNY million·cylinders−1	0.0034	Reagents g	CNY million·cylinders−1	0.00144
	cylinders	26		cylinders	6
Powder d	CNY million·cylinders−1	0.0038	Powder h	CNY million·cylinders−1	0.0529
	cylinders	13		cylinders	9
Powder e	CNY million·kg−1	0.0105	Powder i	CNY million·cylinders−1	0.0015
	kg	51		cylinders	18
Powder f	CNY million·barrel−1	0.012	Electrical power	CNY million·kWh−1	0.000056
	barrel	10		kWh	32,871.48
Total	CNY million·Year−1	609.161

shows the annual cost of expenditures after the project is in operation.

Workers’ wages and welfare are included in the running cost, and there are 25 permanent employees, 18 operating employees, 4 management employees, and 3 leaders. The per capita salary of personnel is calculated at CNY 5000/month (without overtime working hours), and the per capita salary of management personnel is calculated at CNY 7000/month. Specific estimates are shown in

Table 4. Personnel wages.

	Staff	Managerial Staff
Number of staff	18	4
Wages/person—(CNY million-month−1)	0.5	0.7
Wages (CNY million-year−1)	108.0	33.6
Total/ CNY million-year−1	141.60

. The total cost is estimated in

Table 5. Total cost expense estimate.

Number	Project	Annual Running Cost/ CNY Million Year−1
1	Annual depreciation and amortization	60.07
2	Fuel gas	2.42
3	Total material	404.16
4	Total machining	184.32
5	Reagent cost	16.24
6	Water and electricity	2.02
7	Wages and benefits	141.60
9	Maintenance (1%)	3.36
	Total cost	814.19

.

As can be seen from Figure 3, the total annual running cost has the largest percentage of total material cost at 49.64%, followed by total processing cost at 22.641%, and workers’ welfare and salary cost at 17.39%. Figure 4 shows the cost of reagents required to manufacture 96 systems.

3.2.3. Sales Revenue and Tax Estimation

The revenue of this project comes from the SOFC system. The construction period of this project is 3 years, and the first year is 25% of the total investment, the second year is 50%, and the third year is 25%. During the second year of construction, the manufacturer can produce 4 power generation systems per month. In the sixth year and after the intelligent production, the manufacturer can steadily produce 800 units, and the price is CNY 80,000. The annual sales revenue and tax estimates are shown in

Table A1. Economic index of system sales.

Project	1st	2nd	3rd	4th	5th	6th	7th	8th	9th	10th	11th	12th	13th
Sales Volume	0	48	96	192	480	800	800	800	800	800	800	800	800
Annual Sales revenue	0	384	768	1536	3840	6400	6400	6400	6400	6400	6400	6400	6400
Taxes and surcharges	0	19.2	38.4	76.8	192	320	320	320	320	320	320	320	320
Main business cost	0	447.8595	754.119	1366.64	3204.2	5245.93	5246.59	5245.93	5245.925	5245.925	5245.925	5245.925	5245.925
Sales profit	0	−83.0595	−24.519	92.562	443.805	834.075	833.408	834.075	834.075	834.075	834.075	834.075	834.075
overhead	0	1.536	3.072	6.144	15.36	25.6	25.6	25.6	25.6	25.6	25.6	25.6	25.6
Selling expenses	0	0.768	1.536	3.072	7.68	12.8	12.8	12.8	12.8	12.8	12.8	12.8	12.8
Total profit	0	−85.3635	−29.127	83.346	420.765	795.675	795.008	795.675	795.675	795.675	795.675	795.675	795.675
Income tax	0	−12.8045	−4.3691	12.5019	63.1148	119.351	119.251	119.351	119.3513	119.35125	119.35125	119.3513	119.35125
Net profit	0	−72.559	−24.758	70.8441	357.65	676.324	675.757	676.324	676.3238	676.32375	676.32375	676.3238	676.32375
	1	2	3	4	5	6	7	8	9	10	11	12	13
Net cash flow	−699.16	−72.559	−24.758	70.8441	357.65	676.324	675.757	676.324	676.3238	676.32375	676.32375	676.3238	676.32375
Accumulated net cash flow	−699.16	−771.719	−796.48	−725.63	−367.98	308.341	984.098	1660.42	2336.746	3013.0695	3689.3933	4365.717	5042.0408
IRR	32.02%
Pt	5.544092
NPV	CNY 1976.01
	1	2	3	4	5	6	7	8	9	10	11	12	13
Discounted net cash flow	−699.16	−65.9627	−20.461	53.2262	244.28	419.944	381.447	347.061	315.51	286.82729	260.75208	237.0473	215.49759
Accumulated net cash flow discount	−699.16	−765.123	−785.58	−732.36	−488.08	−68.134	313.313	660.374	975.8845	1262.7118	1523.4638	1760.511	1976.0088
Dynamic Pt	6.178619

.

3.3. Life Cycle Cost Analysis

3.3.1. Economic Evaluation Indicators

The economic evaluation is in the form of a survey, analysis, and prediction of various relevant technical and economic factors and programme inputs and outputs during the calculation period of the project programme, and uses indicators to calculate and evaluate the economic effects. A comprehensive economic evaluation is conducted by analyzing the financial feasibility and economic feasibility. According to whether to consider the time value of the economy, economic evaluation indicators can be divided into static evaluation indicators and dynamic evaluation indicators. Static evaluation indicators do not consider the time value of money, and the advantage is easy to calculate and easy to understand, but cannot accurately reflect the actual situation of the investment project. Dynamic evaluation indicators consider the time value of money, such as payback period, net present value, internal rate of return, etc., which are more scientific and comprehensive than static evaluation indicators [25].

• Financial NPV

The Financial Net Present Value (NPV) refers to the cumulative value of the present value of the project according to the sector or industry benchmark rate of return or set discount rate. The net cash flow of each year of the calculation period discounted to the year of the starting point of the construction and is one of the important indicators of the dynamic evaluation of the project, as well as being the main examination of the project in the entire calculation period of the distribution of cash flow at the time of the analysis [26,27,28]. Its expression is:

$$NPV={{\mathsf{\sum }}_{t=1}^n\left(CI-CO\right)}_t{\left(1+i_0\right)}^{-t}$$

(1)

where CI—Cash Inflow, CNY million; CO—Cash Outflow, CNY million;

(CI − CO)_t—Net Cash Flow in year t, CNY million;

i₀—Baseline Discount Rate, %; n—typically the life of the project, years.

• Internal rate of return

The internal rate of return, also known as internal rate of return, is the discount rate when the total present value of capital inflows is equal to the total present value of capital flows and the net present value is equal to zero. It is the project’s maximum resistance to the risk of the initial investment or the project’s maximum rate of currency depreciation that it can withstand. Its expression is:

$${{\sum }_{t=1}^n\left(CI-CO\right)}_t{\left(1+IRR\right)}^{-t}=0$$

(2)

• Payback period

The payback period refers to the time needed to recover all the investment from the date of project construction, which is an indicator reflecting the investment recovery ability [26]. It can be divided into dynamic payback period and static payback period. Its expression is:

$${{\sum }_{t=1}^{P_t}\left(CI-CO\right)}_t=0$$

(3)

As shown in Table A1, the main operating cost of selling 96 units of a power generation system is CNY 7,541,900, the annual sales revenue is CNY 7,680,000, and the administrative expenses are CNY 30,720,000 (overhead rate of 0.4%), selling expenses are CNY 15,360,000 (selling rate of 0.2%), and taxes are CNY 384,000 (after sales tax is 5%). Calculated by the investment cash flow of the IRR of 32.02%, the financial NPV (i₀ = 10%) is CNY 19,763,300, static Pt is 5.544 years (including the construction period), dynamic Pt is 6.179 years (including the construction period), the profitability is better, the Pt is shorter, and the IRR is greater than the industry benchmark rate of return.

3.3.2. Economic Benefits Impact Factor Analysis

This paper selects system material costs, total processing costs (including coating costs and cutting costs), other raw material costs (reagent costs and fuel costs, etc.), construction investment costs, sales prices, wages, and benefits as the influencing factors. Raw materials, materials, and processing costs are shown in Figure 5.

Figure 6 shows the break-even analysis. When the annual production and sales need to reach 19.38% of the design capacity, the goal of break-even can be achieved.

3.3.3. Economic Sensitivity Analysis

The sensitivity analysis of the NPV is presented in the

Table 6. Sensitivity analysis of the NPV of each factor.

Rate of Change	−20%	−10%	0	10%	20%
Stack Materials	0.0408	0.0459	0.051	0.0561	0.0612
The changed material costs	345.408	374.784	404.16	433.536	462.912
The changed business costs	695.367	724.743	754.119	783.495	812.871
NPV/CNY	3802.30	2889.31	1976.33	1063.34	150.36
The changed material costs	323.328	363.744	404.16	444.576	484.992
The changed business costs	732.039	743.079	754.119	765.159	776.199
NPV/CNY	2662.56	2319.44	1976.33	1633.21	1290.10
The changed Sales profits	6.4	7.2	8	8.8	9.6
NPV/CNY	-	−276.90	1976.33	4229.50	6482.78
The changed wages	113.28	127.44	141.6	155.76	169.92
The changed business cost	755.999	770.159	784.319	798.479	812.639
NPV/CNY	2140.35	2058.34	1976.33	1894.32	1812.31
The changed processing cost	147.456	165.888	184.32	202.752	221.184
The changed business cost	688.503	736.311	784.319	831.927	879.735
NPV/CNY	3122.04	2549.18	1976.33	1403.47	830.62
The changed raw material cost	12.9952	14.6196	16.244	17.8684	19.4928
The changed business cost	750.8702	752.4946	754.119	755.7434	757.3678
NPV/CNY	2077.30	2026.81	1976.33	1925.84	1875.36
The changed initial investment	559.328	629.244	699.16	769.076	838.992
NPV/CNY	2116.16	2046.24	1976.33	1906.41	1836.50

.

As can be seen from Figure 7, when the sales price increases, the financial NPV shows a linear growth trend. When the stacking material cost, auxiliary facility material cost, total processing cost, wages and benefits, raw material cost, and construction investment cost increase, the financial NPV shows a decreasing trend. The biggest influence on the NPV among the influencing factors is the sales price: when the sales price decreases by 10%, the financial NPV decreases from CNY 19,763,300 to CNY −2,769,900. This is followed by the stack material cost: when the influencing factor increases from −20% to 20%, the financial NPV decreases from CNY 38,023,000 to CNY 1,503,600.

The sensitivity analysis of the IRR is presented in

Table 7. Sensitivity analysis of the IRR of each factor.

Rate of Change	−20%	−10%	0	10%	20%
Stack Materials	0.0408	0.0459	0.051	0.0561	0.0612
The changed material costs	345.408	374.784	404.16	433.536	462.912
The changed business costs	695.367	724.743	754.119	783.495	812.871
IRR	44.81%	38.87%	32.02%	23.70%	12.41%
The changed material costs	323.328	363.744	404.16	444.576	484.992
The changed business costs	732.039	743.079	754.119	765.159	776.199
IRR	37.27%	34.73%	32.02%	29.12%	25.96%
The changed Sales profits	6.4	7.2	8	8.8	9.6
IRR	-	4.78%	32.02%	47.37%	59.21%
The changed wages	113.28	127.44	141.6	155.76	169.92
The changed business cost	755.999	770.159	784.319	798.479	812.639
IRR	33.99%	33.00%	32.02%	31.05%	30.09%
The changed processing cost	147.456	165.888	184.32	202.752	221.184
The changed business cost	688.503	736.311	784.319	831.927	879.735
IRR	40.46%	36.45%	32.02%	27.03%	21.21%
The changed raw material cost	12.9952	14.6196	16.244	17.8684	19.4928
The changed business cost	750.8702	752.4946	754.119	755.7434	757.3678
IRR	32.84%	32.43%	32.02%	31.61%	31.19%
The changed initial investment	559.328	629.244	699.16	769.076	838.992
IRR	36.31%	34.02%	32.02%	30.25%	28.66%

.

As can be seen from Figure 8, similar to the change rule of the financial NPV, the IRR is affected by factors with a wide range of changes in the sales price. When the sales price decreases by 10%, the IRR decreases from 32.02% to 4.78%; when the cost of stack materials increases from −10% to 10%, the IRR decreases from 38.87% to 23.70%; when ancillary facilities materials costs, wages and benefits, raw material costs, and total machining costs increase, the IRR return falls slightly.

The sensitivity analysis of P_t is presented in

Table 8. Sensitivity analysis of P_t of each factor.

Rate of Change	−20%	−10%	0	10%	20%
Stack Materials	0.0408	0.0459	0.051	0.0561	0.0612
The changed material costs	345.408	374.784	404.16	433.536	462.912
The changed business costs	695.367	724.743	754.119	783.495	812.871
Pt	4.907	5.176	5.544	6.239	8.046
The changed material costs	323.328	363.744	404.16	444.576	484.992
The changed business costs	732.039	743.079	754.119	765.159	776.199
Pt	5.250	5.382	5.544	5.749	6.015
The changed Sales profits	6.4	7.2	8	8.8	9.6
Pt	-	10.478	5.544	4.766	4.302
The changed wages	113.28	127.44	141.6	155.76	169.92
The changed business cost	755.999	770.159	784.319	798.479	812.639
Pt	5.388	5.465	5.544	5.626	5.712
The changed processing cost	147.456	165.888	184.32	202.752	221.184
The changed business cost	688.503	736.311	784.319	831.927	879.735
Pt	5.108	5.291	5.544	5.918	6.528
The changed raw material cost	12.9952	14.6196	16.244	17.8684	19.4928
The changed business cost	750.8702	752.4946	754.119	755.7434	757.3678
Pt	5.493	5.518	5.544	5.571	5.599
The changed initial investment	559.328	629.244	699.16	769.076	838.992
Pt	5.337	5.441	5.544	5.647	5.751

.

As can be seen from Figure 9, the Pt decreases when the selling price increases, and the Pt increases when the stack material cost increases. The Pt increases slowly when the remaining ancillary facility material costs, raw material costs, wage and benefit costs, total processing costs, and construction investment cost variables increase, while it increases significantly when the sales price decreases by 10%, indicating that it will be in the red for a long period of time if the sales pricing decreases by −10%.

From the previous study, it is known that the whole life cycle greenhouse gas emissions of the 2 kW SOFC power generation system are converted to 5592 kg of CO₂ [13], and the whole life cycle greenhouse gas emissions of the same power thermal power generation system [29] are converted to 8638 kg of CO₂. If the thermal power generation system is replaced by this SOFC power generation system, it can reduce CO₂ by 6670.74 kg/y. The pilot policy of China’s carbon trading market has a positive impact on the enterprise’s green innovation [30], and the trading price of the carbon market in the Jiangsu and Zhejiang provinces is generally 50~70 CNY/t [31]. Based on the above economic analysis model, assuming the thermal power generation’s CO₂ emissions for the project’s original carbon credits, the daily trading price is taken as a 10% rate of change and the other values remain unchanged (

Table A2. Economic index of system sales after carbon market trading.

Project	1st	2nd	3rd	4th	5th	6th	7th	8th	9th	10th	11th	12th	13th
Sales Volume	0	48	96	192	480	800	800	800	800	800	800	800	800
Annual Sales revenue	0	384	768	1536	3840	6400	6400	6400	6400	6400	6400	6400	6400
Taxes and surcharges	0	19.2	38.4	76.8	192	320	320	320	320	320	320	320	320
Main business cost	0	447.8595	754.119	1366.638	3204.195	5245.925	5245.925	5245.925	5245.925	5245.925	5245.925	5245.925	5245.925
Sales profit	0	−83.0595	−24.519	92.562	443.805	834.075	834.075	834.075	834.075	834.075	834.075	834.075	834.075
overhead	0	1.536	3.072	6.144	15.36	25.6	25.6	25.6	25.6	25.6	25.6	25.6	25.6
Selling expenses	0	0.768	1.536	3.072	7.68	12.8	12.8	12.8	12.8	12.8	12.8	12.8	12.8
Total profit	0	−85.3635	−29.127	83.346	420.765	795.675	795.675	795.675	795.675	795.675	795.675	795.675	795.675
Income tax	0	−12.804525	−4.36905	12.5019	63.11475	119.35125	119.35125	119.35125	119.35125	119.35125	119.35125	119.35125	119.35125
Carbon trading price	0	2.113290432	4.226580864	8.453161728	21.13290432	35.2215072	35.2215072	35.2215072	35.2215072	35.2215072	35.2215072	35.2215072	35.2215072
Net profit	0	−70.445684	−20.531369	79.29726173	378.7831543	711.5452572	711.5452572	711.5452572	711.5452572	711.5452572	711.5452572	711.5452572	711.5452572
	1	2	3	4	5	6	7	8	9	10	11	12	13
Net cash flow	−699.16	−70.445684	−20.531369	79.29726173	378.7831543	711.5452572	711.5452572	711.5452572	711.5452572	711.5452572	711.5452572	711.5452572	711.5452572
Accumulated net cash flow	−699.16	−769.60568	−790.13705	−710.839792	−332.05663	379.4886195	1091.033877	1802.579134	2514.124391	3225.669648	3937.214906	4648.760163	5360.30542
IRR	33.27%
Pt	5.466669736
NPV	¥2130.87
	1	2	3	4	5	6	7	8	9	10	11	12	13
Discounted net cash flow	−699.16	−64.041531	−16.968073	59.57720641	258.7139911	441.8136225	401.6487477	365.1352252	331.9411138	301.7646489	274.331499	249.3922719	226.7202471
Accumulated net cash flow discount	−699.16	−763.20153	−780.16960	−720.59239	−461.87840	−20.0647851	381.5839626	746.7191879	1078.660302	1380.424951	1654.75645	1904.148722	2130.868969
Dynamic Pt	6.04995605

), then the impact of the changed results on the project’s financial NPV and IRR is shown in Figure 10.

As can be seen from Figure 10, the daily carbon trading price changes in the financial NPV and IRR impact are consistent, and the higher the daily carbon trading price, the higher the financial NPV and IRR. In the low carbon context, promoting SOFC systems has economic potential compared to traditional energy generation modes.

4. Conclusions

This paper presents an economic analysis of the 2 kW SOFC system by modelling the economic flow analysis. With respect to previous research, this paper expands the economic analysis of the life cycle of low-power household SOFC systems, and makes it easier for enterprises to adjust the cost structure by evaluating the cost at each stage of the product. On the basis of comprehensive economic indicators such as the NPV, Pt, and IRR, an economic analysis of carbon market trading is conducted compared with traditional power generation systems, and the economic potential of SOFC systems for market promotion is evaluated based on case data. The results show that the construction period of the project is 3 years, the operating life is 10 years, the depreciation life of fixed assets is 10 years, the annual rate of return is about 10%, and the total material cost accounts for the largest proportion of 49.64%, followed by the total processing cost of 22.641%. Workers’ welfare and salary costs accounted for 17.39%, and when the annual production and sales need to reach 19.38% of the design capacity, the goal of break-even can be achieved. Changes in the daily carbon trading price have a consistent impact on the financial NPV and IRR. The higher the daily carbon trading price, the higher the financial NPV and IRR increase, and in the low carbon context, compared with the traditional energy generation model, promoting SOFC systems seems to have a good economic potential and prospects for large-scale commercialization and expansion.