pv system analysis

Photovoltaic System Analysis

The following analysis was produced to predict the best photovoltaic system that would yield the

highest annual savings and the fastest return period with high performance. The energy consumption for

the building was first calculated to address the PV system size requirements. Table 1: Building

Consumption has the designated kWh/day required for this facility and the available roof area for the

solar panels.

With this information a better cost comparison was created. Table 2: Cost Analysis compares the

four distinct solar panels that have qualified for CPS rebate and have high performance. The first option

was the one UTSA has used, the second is one of the panels with the highest wattage in the market, and

the last two have the lowest price to wattage ratio. All solar panels have high performance ratings.

Moreover, Table 2 predicts the daily production of kWh/day and the PV system size for each distinct

solar panel. Table 2: Cost Analysis takes into account the prices of the panels (obtained from

http://www.affordable-solar.com). The installation cost was estimated by 411 Energy LLC, who is a

solar rebate contractor that meets the qualifications for CPS rebate by being NABCEP Certified. The

North American Board of Certified Energy Practitioners (NABCEP) is the “gold standard” for PV and

solar heating installation certification. This certification is designed to raise industry standards and

promote consumer confidence. In terms of rebate, the $100,000 comes from the CPS Energy Solar

Initiative Rebate Program. This rebate program provides tiered incentives ranging from $1.30 to $2.50

per AC watt based on the calculated expected performance of the system with a rebate of up to $100,000

for commercial installations. With this information the total cost for each system was acquired.

After estimating the system’s cost, Table 3: Financial Performance was constructed to do the

final comparison of the electric monthly bill, monthly savings, return period and price per kW. This

table was populated through the use of the result acquired from tables 4-7. The four different system’s

financial projections, see table 4-7, were constructed using the following assumptions. A 6.95 cents per

kWh current electrical cost with a 4.35% annual increase, and an annual kWh production degradation of

0.05% per year based on manufacturer’s warranty guideline. The projected kWh production was based

on the National Renewable Energy Laboratory’s “PV Watts" Performance Calculator. Table 4-7 have

the calculations for all four PV systems return period.

In summary, efficient option 2 (CS6P 240 Canadian Solar) has the lowest return period, lowest

cost per kW, second to the highest percentage of solar energy bill, and second to the highest monthly

savings as seen in Table 3: Financial Performance. For these reasons this will be the chosen solar panel.

The final PV system will be a 87.2 kW system with 167,935 kWh average annual production and

$14,282 average yearly savings. Additionally, a 30% tax credit will be applicable under the Federal Tax

Credits for Consumer Energy Efficiency.

http://www.affordable-solar.com/

Table 1: Building Consumption

Size sq. ft. 23,000.00

Building Energy Consumption kWh/day 1,474.52

Solar Panel Roof Area sq. ft. 6,300

Table 2: System Cost Analysis

1 2 3 4 5

Type UTSA Option E-20-435 Efficient Option 1 Efficient Option 2 No Solar Power

Size (kW) 84.00 117.79 86.84 87.23 -

Cost of each panel $314.12 - $342.00 $280.59 -

Cost of System $109,942.00 $ 6 per watt $104,213.13 $101,977.54 -

Cost of Installation $336,000.00 $706,718.19 $347,377.11 $348,902.11 -

Cost of Inverters, etc. $40,000.00 $40,000.00 $40,000.00

*CPS Rebate $100,000.00 $100,000.00 $100,000.00 $100,000.00 -

Total System Cost $385,942 $606,718 $391,590 $390,880 -

Comparison of the four chosen panels that qualify for the CPS rebate and outputs the total system cost.

*This estimate presumes that the local utility, CPS Energy, provides close to $100,000 as part of their renewable

energy incentive program. The actual value may differ depending on circumstances interpretation, date

restrictions, and other incentive guidelines.

Table 3: Financial Performance

Type 1

UTSA Option

2

E-20-435

3

Efficient Option 1

4

Efficient Option 2

5

No Solar Power

Total Electric Cost

monthly $2,176 $1,797 $2,147 $2,140 $3,117

Monthly Savings $941 $1,320 $971 $977 0

Return Period (yr.) 21.3 23.1 21.2 21.1

$/kW $4,594.55 $5,151.01 $4,509.11 $4,481.25

Table 4: UTSA OPTION

Year

Solar Electric Energy

Generation (kWh/yr.) Price/kWh

Avoided Cost

from Electric

Generation

Cumulative

Savings

1 162,421 0.070 $11,288 $11,288

2 163,981 0.073 $11,892 $23,181

3 163,899 0.076 $12,404 $35,584

4 163,817 0.079 $12,937 $48,521

5 163,735 0.082 $13,493 $62,013

6 163,653 0.086 $14,073 $76,086

7 163,571 0.090 $14,677 $90,763

8 163,490 0.094 $15,308 $106,071

9 163,408 0.098 $15,966 $122,038

10 163,326 0.102 $16,652 $138,690

11 163,245 0.106 $17,368 $156,058

12 163,163 0.111 $18,114 $174,172

13 163,081 0.116 $18,893 $193,065

14 163,000 0.121 $19,705 $212,770

15 162,918 0.126 $20,552 $233,322

16 162,837 0.132 $21,435 $254,757

17 162,755 0.137 $22,356 $277,113

18 162,674 0.143 $23,317 $300,430

19 162,593 0.150 $24,319 $324,749

20 162,511 0.156 $25,364 $350,114

21 162,430 0.163 $26,455 $376,568

22 162,349 0.170 $27,592 $404,160

Key Metrics Value

PV System $485,942

CPS Rebate $100,000

Total System $385,942

Estimated Simple Payback 21.3 years

Table 5: E-20-435

Year



Avoided Cost

from Electric

Generation

Cumulative

Savings

1 227,858 0.070 $15,836 $15,836

2 227,858 0.073 $16,525 $32,361

3 227,744 0.076 $17,235 $49,596

4 227,630 0.079 $17,976 $67,572

5 227,516 0.082 $18,749 $86,321

6 227,402 0.086 $19,554 $105,875

7 227,289 0.090 $20,395 $126,270

8 227,175 0.094 $21,271 $147,541

9 227,061 0.098 $22,185 $169,726

10 226,948 0.102 $23,139 $192,865

11 226,834 0.106 $24,133 $216,999

12 226,721 0.111 $25,171 $242,169

13 226,608 0.116 $26,252 $268,422

14 226,494 0.121 $27,381 $295,802

15 226,381 0.126 $28,557 $324,360

16 226,268 0.132 $29,785 $354,145

17 226,155 0.137 $31,065 $385,209

18 226,042 0.143 $32,400 $417,609

19 225,929 0.150 $33,792 $451,402

20 225,816 0.156 $35,245 $486,647

21 225,703 0.163 $36,760 $523,406

22 225,590 0.170 $38,339 $561,746

23 225,477 0.177 $39,987 $601,733

24 225,364 0.185 $41,706 $643,439

Key Metrics Value

PV System $706,718

CPS Rebate $100,000



Table 6: Efficient Option 1

Year



Avoided Cost

from Electric

Generation

Cumulative

Savings

1 168,000 0.070 $11,676 $11,676

2 168,000 0.073 $12,184 $23,860

3 167,916 0.076 $12,708 $36,568

4 167,832 0.079 $13,254 $49,821

5 167,748 0.082 $13,823 $63,645

6 167,665 0.086 $14,417 $78,062

7 167,581 0.090 $15,037 $93,099

8 167,497 0.094 $15,683 $108,782

9 167,413 0.098 $16,357 $125,140

10 167,329 0.102 $17,060 $142,200

11 167,246 0.106 $17,794 $159,994

12 167,162 0.111 $18,558 $178,552

13 167,079 0.116 $19,356 $197,908

14 166,995 0.121 $20,188 $218,096

15 166,912 0.126 $21,055 $239,152

16 166,828 0.132 $21,960 $261,112

17 166,745 0.137 $22,904 $284,016

18 166,661 0.143 $23,889 $307,905

19 166,578 0.150 $24,915 $332,820

20 166,495 0.156 $25,986 $358,806

21 166,411 0.163 $27,103 $385,909

22 166,328 0.170 $28,268 $414,177

Key Metrics Value

PV System $491,590

CPS Rebate $100,000



Table 7: Efficient Option 2

Year



Avoided Cost

from Electric

Generation

Cumulative

Savings

1 168,738 0.070 $11,727 $11,727

2 168,738 0.073 $12,237 $23,965

3 168,653 0.076 $12,763 $36,728

4 168,569 0.079 $13,312 $50,040

5 168,485 0.082 $13,884 $63,924

6 168,401 0.086 $14,481 $78,405

7 168,316 0.090 $15,103 $93,508

8 168,232 0.094 $15,752 $109,260

9 168,148 0.098 $16,429 $125,689

10 168,064 0.102 $17,135 $142,824

11 167,980 0.106 $17,872 $160,696

12 167,896 0.111 $18,640 $179,336

13 167,812 0.116 $19,441 $198,777

14 167,728 0.121 $20,276 $219,053

15 167,644 0.126 $21,148 $240,201

16 167,560 0.132 $22,057 $262,258

17 167,477 0.137 $23,005 $285,263

18 167,393 0.143 $23,994 $309,257

19 167,309 0.150 $25,025 $334,281

20 167,226 0.156 $26,100 $360,381

21 167,142 0.163 $27,222 $387,603

22 167,058 0.170 $28,392 $415,995

Key Metrics Value

PV System $490,880

CPS Rebate $100,000



pv system analysis

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