pv magazine test – February 2019 results

Share

The first chart to the right depicts the meteo station data (irradiance and ambient temperature) for February 2019. The monthly energy yield data for the months from September 2018 to February 2019 is given in the Energy yield ranking table below. The second chart to the right shows the total energy yield for February 2019. Bifacial and mono PERC products continue to occupy the top five positions.

Of the 28 days in February 2019, 20 were hazy days in Xi’an, due to the Chinese New Year firework activity. The bifacial boost in February almost doubled with respect to the January value. (See table below left for detailed information). Haze reduces direct irradiation, which results in lower yield from the front side, whereas the diffuse irradiation has a much higher impact on the rear side yield. In hazy conditions the diffuse portion is higher, therefore the bifacial boost goes up.

Bifacial and diffuse irradiation

Bifacial boost and diffuse irradiation stayed in sync for most of the month, except on Feb. 10th and 18th, when bifacial boost spiked to 55% and 22% respectively (normal range is 5% -10%). Our investigation of the hourly energy yield data as well as the review of the CCTV footage identified that the root cause was snow coverage on the monofacial modules on both days, which brought down the mono-facial energy yield and resulted in unusually high bifacial boost. It is known that bifacial modules produce energy from the rear side even when covered, which results in faster snow shedding. This, together with the increased albedo of snowed grounds gives a big advantage to bifacial modules in snow. George Touloupas

Bifacial boost data

Sep 2018 Wh/Wp

Oct 2018 Wh/Wp

Nov 2018 Wh/Wp

Dec 2018 Wh/Wp

Jan 2019 Wh/Wp

Feb 2019 Wh/Wp

Average monthly yield

99.60

123.28

74.53

65.49

65.12

75.31

Average monthly bifacial yield

103.19

127.55

76.90

67.52

67.00

79.46

Average monthly monofacial yield

98.94

122.50

73.89

64.99

64.64

74.28

Operation days

30

31

30

31

31

28

Average daily yield

3.32

3.98

2.48

2.11

2.10

2.69

Average daily bifacial yield

 

3.44

4.11

2.56

2.18

2.16

2.84

Average daily monofacial yield

3.30

3.95

2.46

2.10

2.09

2.65

Bifacial boost

4.3%

4.1%

4.1%

3.9%

3.7%

7.0%

Energy yield ranking

#

Product

Type

Total Sep 2018 Wh/Wp

Total Oct 2018 Wh/Wp

Total Nov 2018 Wh/Wp

Total Dec 2018 Wh/Wp

Total Jan 2019 Wh/Wp

Total Feb 2019 Wh/Wp

Grand Total Wh/Wp

Sep 2018 rank

Oct 2018 rank

Nov 2018 rank

Dec 2018 rank

Jan 2019 rank

Feb 2019 rank

18

LONGi LR6-60BP-300M

Bifacial Mono PERC

78.74

68.82

68.07

81.23

296.9

1

1

1

1

17

NSP D6L310L3A

Bifacial Mono PERC

103.64

128.10

76.51

67.05

66.96

78.91

914.3

1

1

3

2

2

2

1

Jolywood JW-D60N-305

Bifacial N-PERT

102.73

127.00

75.44

66.68

65.98

78.22

907.4

2

2

5

4

4

3

16

LONGi LR6-60PE-310M 2

Mono PERC

101.43

125.30

76.57

67.05

66.40

76.43

892.9

3

4

2

3

3

4

7

LONGi LR6-60PE-310M 1

Mono PERC

100.57

125.40

75.57

66.24

65.58

75.79

893.7

4

3

4

5

5

5

10

Recom RCM-275-6MB-4-BB21

Mono

99.46

123.30

74.09

65.31

65.06

74.62

876.3

6

6

7

6

7

6

12

NSP D6LM305E3A

Mono PERC

97.29

120.30

72.17

63.80

63.79

74.54

862.5

12

13

14

14

14

7

14

Sample 2

Mono PERC

96.85

121.70

73.92

65.12

64.79

74.50

871.0

13

9

8

9

8

8

4

Perlight PLM-300M-60

Mono PERC

98.77

122.40

73.68

65.14

65.15

74.48

876.1

9

8

9

8

6

9

20

Phono PS380MH-24/TH

Mono PERC

65.10

64.66

74.38

204.1

10

11

10

8

Aiduo AD280-60S

Mono

98.76

121.50

74.13

65.04

64.69

74.18

867.6

10

10

6

11

10

11

13

Sample 1

Mono

98.86

120.30

73.12

65.26

64.76

73.62

853.7

8

12

12

7

9

12

9

Aiduo AD265-60P

Multi

97.48

120.80

73.10

64.29

64.06

73.55

865.6

11

11

13

12

12

13

2

Phono MWT-60-280

Multi MWT

99.53

123.60

73.15

63.52

62.76

72.64

869.8

5

5

11

15

15

14

3

Risen RSM60-6-270P

Multi

99.39

122.90

73.28

63.99

64.02

72.61

868.9

7

7

10

13

13

15

 

Notes on the energy yield measurements:

  • The energy yield is given in Wh/Wp and calculated by dividing the energy produced by the module by the Pmax at STC of the module. This Pmax is the maximum STC power after a process of stabilization.
  • The results are grouped in categories, per module type.
  • The bifacial boost depends on many parameters: the bifaciality factor, the installation geometry, the albedo of the ground, and also the sun angle and diffuse irradiance. The ground in this case is a plastic cover simulating green grass.