passive detached single family house in aylesbury · energelio tél. :+33 (0)3.20.52.44.20 7 rue de...

ENERGELIO Tél. :+33 (0)3.20.52.44.20

7 rue de l’Hôpital Militaire E-mail : [email protected]

F-59800 LILLE

Passive detached single family house in

Aylesbury

Feasibility study of a photovoltaic self-consumption

system

PH+PV

29/04/2016

N°Affaire Phase Mission Indice Auteur Validé

16044 PH+PV Conseil 1 CT CC

| 27

SUMMARY

1 - MAIN FINDINGS DEVELOPPED IN THIS REPORT ____________________ 4

2 - INTRODUCTION ________________________________________________ 5

3 - PHOTOVOLTAIC SYSTEM _______________________________________ 5

4 - DEMAND ANALYSIS ____________________________________________ 6

4.1 - Domestic use _________________________________________________________ 6

4.2 - Domestic Hot Water ____________________________________________________ 7

4.3 - Heating system ________________________________________________________ 7

4.4 - Combined demand profile _______________________________________________ 8

4.5 - Load and generation ___________________________________________________ 8

5 - STATIC HOURLY MODEL _______________________________________ 10

5.1 - Protocol _____________________________________________________________ 10

5.2 - Profiles _____________________________________________________________ 10

5.2.1 - Heating _________________________________________________________________ 10

5.2.2 - DHW ___________________________________________________________________ 11

5.2.3 - Electricity demand (all uses except heating and DHW) _________________________ 11

5.3 - Daily consumption ____________________________________________________ 12

5.3.1 - Annual scale ____________________________________________________________ 12

5.3.2 - Focus on winter __________________________________________________________ 12

5.4 - Peak loads ___________________________________________________________ 13

6 - SOLAR AUTOCONSUMPTION RESULTS __________________________ 14

6.1 - Selfconsumption ratio _________________________________________________ 14

6.2 - Grid electricity purchase ___________________________________________ 15

| 27

6.3 - Detailed results with a 5 kWh battery ____________________________________ 16




6.7 - Grid electricity sales___________________________________________________ 18

6.7.1 - Annual scale ____________________________________________________________ 18

6.7.2 - 5 kWh grid sales _________________________________________________________ 19

6.7.3 - 10 kWh grid sales ________________________________________________________ 19

6.7.4 - 15 kWh grid sales ________________________________________________________ 20

6.7.5 - 40 kWh grid sales ________________________________________________________ 20

6.7.6 - Findings ________________________________________________________________ 21

7 - PEAK LOAD REDUCTION _______________________________________ 22

7.1 - Peak demand with no battery ___________________________________________ 23

7.2 - Peak demand with 5 kWh battery ________________________________________ 23

7.3 - Peak demand with 15 kWh battery _______________________________________ 24

7.4 - Peak demand with 40 kWh battery _______________________________________ 24

7.5 - Comparison with a classic housing ______________________________________ 25

8 - OTHER LEADS ________________________________________________ 26

8.1 - Smart system for solar self-consumption _________________________________ 26

8.1.1 - MyLight System’s Kit _____________________________________________________ 26

8.1.1 - Victron HUB 4 system _____________________________________________________ 27

| 27

1 - MAIN FINDINGS DEVELOPPED IN THIS REPORT

Electricity for Domestic use and Domestic Hot Water (DHW) system are the main electricity

consumers: this is the “Passivehouse effect”.

Thanks to the HP system, peak loads are very low. The maximum mean load observed is around 2.5 kW during winter.

In mid-season + summer, mean load is around 1 kW.

The solar self-consumption ratio, which represents the combination of PV generation directly

used + the battery charge used, presents a logarithmic behavior when the capacity increases.

This is very important to note that considering the high power level installed (12.4 kWc), the self-

consumption ratio without battery is already high. Installing a battery will rise up the ratio.

From our point of view, a ratio between 75% and 80% is a good value in individual housing. For

instance, a battery capacity around 13 kWh represents a 78.6% self-consumption ratio.

Concerning grid electricity purchases, we can also notice a logarithmic behavior: the first kWhs installed allow a grid electricity purchases reduction. However, the reduction is limited. This behavior is only due to the winter period.

Installing batteries can reduce the annual grid sales, but not in summer. Again, we can notice a logarithmic behavior. Summer sales always represent a huge part.

Batteries can reduce peak demand. When we draw the reduced peak demand regarding battery capacity, we can find an optimal area around 15 kWh.

Compared to a classic housing, peak loads can be reduced here by more than 80%.

To go further, it can be very interesting to install a smart system to increase the self-consumption ratio.

0,5

0,55

0,6

0,65

0,7

0,75

0,8

0,85

0 5 10 15 20 25 30 35 40 45

SOLA

R A

UTO

CO

NSU

MP

TIO

N R

ATI

O

BATTERY CAPACITY (KWH)

Solar autoconsumption : gen directly used + battery

350

400

450

500

550

600

0 5 10 15 20 25 30 35 40 45

HO

UR

S /

YEA

R


Hours / year when peak load is above 1 kW

| 27

2 - INTRODUCTION

Lark Rise is a PassiveHouse standard project: the most advanced energy standard worldwide. This project is also equipped with a 12.4 kWp PV array on the roof. Moreover, it is very likely that this project be eligible for the new PassivHouse Plus label. The aim of the study is to quantify the self-consumption potential, and also to estimate how much the winter peak load demand can be reduced. In this report, we will focus on 3 main subjects:

1. What is the best battery size? 2. Can we reduce peak loads with a battery? 3. Compared to a classic building, is the winter

electrical load peak reduced?

3 - PHOTOVOLTAIC SYSTEM

The photovoltaic system of the passive house generates 12.4 kWp with

38 solar panels. Each panel is a Sunpower model with a 10-degree

angle with the horizontal. Regarding the location and the direction of the

house, 10,978 kWh of energy is produced every year.

According to our calculations, more than 45% of the annual photovoltaic production is not used and has to be injected into the grid. Regarding this figure, we propose to define which strategy can be set up in the passive house for controlling this energy production.

-

200

400

600

800

1 000

1 200

1 400

1 600

1 800

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Monthly solar PV generation

| 27

4 - DEMAND ANALYSIS

For our calculations, we built a consumption profile including: domestic use, DHW and heating demand.

Domestic use and Domestic Hot Water (DHW) system are the main electricity consumers: this is the

“Passivehouse effect”.

4.1 - Domestic use

The refrigerator, the freezer and the ventilation system need to be provided in electricity all the time, in a

constant way. It is constant demand.

Some appliances, such as the dishwashing and the clothes washing, need to be scheduled for immediate

and ulterior use. It is programmable demand.

Lighting, cooking and consumer electronics are considered as floating demand. These items consume

more electricity than the previous items and they are less predictable. But this demand can be easily

decreased. Indeed, they depend on the following parameters: family behavior, weather, etc.

286

251

200

285

321

32

128

500

176

-

500

1 000

1 500

2 000

2 500

kWh

/ye

ar

Electricity Demand

Consumer electronics

Cooking

Lighting

Ventilation

Freezing

Refrigerating

Small appliances

Clothes washing

Dishwashing

Constant demand

Programmable

demand

Floating demand

| 27

4.2 - Domestic Hot Water

DHW can be considered as a deferrable demand.

Water is heated, accumulated in a tank and can be

used later.

The domestic hot water consumption is equal to 844

kWh per year (according to PHPP with a 2.8

SCOP).

4.3 - Heating system

The heat pump covers 100% of space heating

demand.

Annual heating demand is equal to 15.1 kWh/m²

per year, that is to say 2702.9 kWh per year. With

a 2.8 SCOP, the annual heating consumption

remains very low: 991 kWh per year.

844

-

100

200

300

400

500

600

700

800

900

1 000

kWh

/ye

ar

DHW consumption (PHPP)


991

0

100

200

300

400

500

600

700

800

900

1000

kWh

/ye

ar

Annual heating consumption (PHPP)


| 27

4.4 - Combined demand profile

4.5 - Load and generation

Optimization of the photovoltaic production depends on balance between load and generation.

The management system has to be designed for consuming the generated energy for the following energy

consumption items:

- Constant demand is the first item which consumes solar generation;

- After constant demand, solar generation provides energy for domestic hot water. Water can be easily

heated and stored for a non-immediate use;

- If there is an electricity surplus, it can be used for programmable demand and also for heating.

286

251

200

285

321

32

128

500

176

844 991

-

500

1 000

1 500

2 000

2 500

Domestic Use DWH consumption Heating consumption

kWh

/ye

ar

Lark Rise - Annual Electricity Demand




Cooking

Lighting

Ventilation

Freezing

Refrigerating

Small appliances

Clothes washing

Dishwashing

| 27

On an annual basis, we can notice that the PV production is about 2.5 times higher than electricity demand.

Basically, with a monthly approach, the maximum energy consumption from the building doesn’t coincide

with the maximum energy generation from the photovoltaic system. There is an electricity surplus between

March and October.

844

991

10979

0

2000

4000

6000

8000

10000

12000

Global electricity Demand PV generation

kWh

/ye

ar

Lark Rise - Annual Electricity Demand

PV generation




Cooking

Lighting

Ventilation

Freezing

Refrigerating

Small appliances

Clothes washing

Dishwashing

-

200

400

600

800

1 000

1 200

1 400

1 600

1 800


Monthly solar PV generation vs Load

| 27

5 - STATIC HOURLY MODEL

5.1 - Protocol

The static model is based on an 8760 hours excel model and consists in comparing battery scenarios with

one demand profile. We allowed ourselves to use some methods developed in the Darke and Taylor’s excel

worksheet. The profile is considered as a constant demand per day from the domestic use, combined with

the heating system consumption and finally the DHW system.

5.2 - Profiles

5.2.1 - Heating

The heating profile is calculated with a dynamic model, based on a PH building with the same time constant

and adapted to the weather data.

(typical day)

0,0

1,0

2,0

3,0

4,0

5,0

6,0

12

75

54

98

23

10

97

13

71

16

45

19

19

21

93

24

67

27

41

30

15

32

89

35

63

38

37

41

11

43

85

46

59

49

33

52

07

54

81

57

55

60

29

63

03

65

77

68

51

71

25

73

99

76

73

79

47

82

21

84

95

THEORICAL HEATING DEMAND

| 27

5.2.2 - DHW

DHW is supposed to be launched during the day, when the PV is producing.

5.2.3 - Electricity demand (all uses except heating and DHW)

Electricity demand profile for all uses is following. During the day, we assume that the dishwasher and the

washing machine is programmed to run between 11am and 3pm.

| 27

5.3 - Daily consumption

5.3.1 - Annual scale

On an annual scale, the daily consumption is constant in mid-season and summer. In winter, peak consumption appears, due to the heating demand.

5.3.2 - Focus on winter

In winter, daily consumption is variable. However, it is interesting to note that mean consumption is around 19 kWh/day.

0

5

10

15

20

25

30

35

40

11

12

13

1

41

51

61

71

81

91

10

11

11

12

1

13

1

14

11

51

16

11

71

18

1

19

12

01

21

12

21

23

1

24

12

51

26

12

71

28

1

29

13

01

31

13

21

33

1

34

13

51

36

1

Daily consumption / Annual scale

Daily constant

consumption

Heating peaks

Mean

value :

19 kWh/day

| 27

5.4 - Peak loads

This graph is showing to main conclusions:

1. Thanks to the HP system, peak loads are very low. The maximum mean load observed is around 2.5 kW during winter, which is very low.

2. In mid-season + summer, mean load is around 1 kW. Here is a focus of peak loads in winter:

0,000

0,500

1,000

1,500

2,000

2,500

3,000

12

84

56

78

50

11

33

14

16

16

99

19

82

22

65

25

48

28

31

31

14

33

97

36

80

39

63

42

46

45

29

48

12

50

95

53

78

56

61

59

44

62

27

65

10

67

93

70

76

73

59

76

42

79

25

82

08

84

91

ANNUAL LOAD PROFILE

Max 2.5kW

Base : 1kW

| 27

6 - SOLAR AUTOCONSUMPTION RESULTS

6.1 - Selfconsumption ratio

We chose to look at the solar self-consumption ratio, which represents the combination of PV generation

directly used + the battery charge used.

As expected, we notice a logarithmic behavior: the first kWh is most effective.

This is very important to note that considering the high power level installed (12.4 kWp), the self-consumption

ratio without battery is already high. Installing a battery will rise up the ratio.

From our point of view, a ratio between 75% and 80% is a good value in individual housing. For instance,

a battery capacity around 13 kWh represents a 78.6% self-consumption ratio.

0,5

0,55

0,6

0,65

0,7

0,75

0,8

0,85

0 5 10 15 20 25 30 35 40 45

SOLA

R A

UTO

CO

NSU

MP

TIO

N R

ATI

O


Solar autoconsumption : gen directly used + battery

| 27

6.2 - Grid electricity purchase

The following curve shows the grid electricity purchase linked to the battery capacity. For this indicator, we can also notice a logarithmic behavior: the first kWhs installed allow a reduction of grid electricity purchase. However, the reduction is limited. This behavior is due to the winter period.

0

500

1000

1500

2000

2500

0 5 10 15 20 25 30 35 40 45

KW

H /

YEA

R


Grid electricity purchase

| 27

6.3 - Detailed results with a 5 kWh battery


189 199 238 255

287 287 295 281 227

202 175 175

61 83

104 83 63 51 55 69

89 111

69 58

368

234 85

4 0 0 0 0 22 37

243

408

-

100

200

300

400

500

600

700


5 kWh- Monthly dataDirect autoconsumption Battery Charge Used Grid Electricity

189 199 238 255

287 287 295 281 227 202 175 175

96 134

138 88 63 51 55 69

105 133

113 86

333 183

52

0 0 0 0 0 6 14

199

380

-

100

200

300

400

500

600

700



| 27



189 199 238 255

287 287 295 281 227 202 175 175

114

166

158 88

63 51 55 69 111 142

130 94

315 152

32

0 0 0 0 0 0 6

182

372

-

100

200

300

400

500

600

700



189 199 238 255

287 287 295 281 227

202 175 175

156 195

186 88

63 51 55 69

111 148 193

95

273 122

4

0 0 0 0 0 0 0

119 371

-

100

200

300

400

500

600

700



| 27

6.7 - Grid electricity sales

6.7.1 - Annual scale

Installing batteries can reduce the annual grid sales, but not in Summer. Again, we can notice a logarithmic behavior. Summer sales always represent a huge part. We can see this phenomenon with the detailed graphs below:

6500

7000

7500

8000

8500

9000

0 5 10 15 20 25 30 35 40 45

KW

H /

YEA

R


Annual Grid sales

0

2

4

6

8

10

12

12

84

56

78

50

11

33

14

16

16

99

19

82

22

65

25

48

28

31

31

14

33

97

36

80

39

63

42

46

45

29

48

12

50

95

53

78

56

61

59

44

62

27

65

10

67

93

70

76

73

59

76

42

79

25

82

08

84

91

KW

GRID REINJECTION

| 27

6.7.2 - 5 kWh grid sales


96 221

512

845

1 160 1 180 1 218

1 075

669

340

157 38 -

200

400

600

800

1 000

1 200

1 400


5 kWh - Monthly dataGrid sales

62 168

473

840

1 160 1 180 1 218

1 075

652

320

112 9 -

200

400

600

800

1 000

1 200

1 400



| 27



44 133

449

840

1 160 1 180 1 218

1 075

646

316

94 1 -

200

400

600

800

1 000

1 200

1 400



8 81

421

840

1 160 1 180 1 218

1 075

646

316

43 - -

200

400

600

800

1 000

1 200

1 400



| 27

6.7.6 - Findings

Those detailed graph show that even if we install a huge battery capacity (40 kWh here), grid sales cannot be reduced during the March October period. It also means that batteries cannot reduce peak reinjection loads into the grid.

| 27

7 - PEAK LOAD REDUCTION

As seen previously, peak loads reach about 2.5 kW. Normal load represents 1 kW. Besides, we noticed to choose a battery size, we miss a parameter. Self-consumption ratio is not sufficient. Considering this, we would like to know what size of battery could authorize a peak load reduction from 2.5 kW to 1kW in winter.

0,000

0,500

1,000

1,500

2,000

2,500

3,000

12

84

56

78

50

11

33

14

16

16

99

19

82

22

65

25

48

28

31

31

14

33

97

36

80

39

63

42

46

45

29

48

12

50

95

53

78

56

61

59

44

62

27

65

10

67

93

70

76

73

59

76

42

79

25

82

08

84

91

ANNUAL LOAD PROFILE

Max 2.5kW

Base : 1kW

350

400

450

500

550

600

0 5 10 15 20 25 30 35 40 45

HO

UR

S /

YEA

R


Hours / year when peak load is above 1 kW

Optimal area

| 27

7.1 - Peak demand with no battery

7.2 - Peak demand with 5 kWh battery

0

0,5

1

1,5

2

2,5

12

67

53

37

99

10

65

13

31

15

97

18

63

21

29

23

95

26

61

29

27

31

93

34

59

37

25

39

91

42

57

45

23

47

89

50

55

53

21

55

87

58

53

61

19

63

85

66

51

69

17

71

83

74

49

77

15

79

81

82

47

85

13

GRID PEAK DEMAND - 0 KWH

0

0,5

1

1,5

2

2,5

12

67

53

37

99

10

65

13

31

15

97

18

63

21

29

23

95

26

61

29

27

31

93

34

59

37

25

39

91

42

57

45

23

47

89

50

55

53

21

55

87

58

53

61

19

63

85

66

51

69

17

71

83

74

49

77

15

79

81

82

47

85

13


| 27


15 kWh appears to be a good compromise between investment and peak load reduction here.


We can see here that even with a 40 kWh battery, peak demand above 1 kW still exists and happens in Winter.

0

0,5

1

1,5

2

2,5

12

67

53

37

99

10

65

13

31

15

97

18

63

21

29

23

95

26

61

29

27

31

93

34

59

37

25

39

91

42

57

45

23

47

89

50

55

53

21

55

87

58

53

61

19

63

85

66

51

69

17

71

83

74

49

77

15

79

81

82

47

85

13


0

0,5

1

1,5

2

2,5

12

67

53

37

99

10

65

13

31

15

97

18

63

21

29

23

95

26

61

29

27

31

93

34

59

37

25

39

91

42

57

45

23

47

89

50

55

53

21

55

87

58

53

61

19

63

85

66

51

69

17

71

83

74

49

77

15

79

81

82

47

85

13


| 27

7.5 - Comparison with a classic housing

We can see here that compared to a classic house, the Lark Rise project with a 15 kWh battery reduces its peak load demand by more than 80%.

0

2

4

6

8

10

12

14

16

18

20

11

17

23

33

49

46

55

81

69

78

13

92

91

04

51

16

11

27

71

39

31

50

91

62

51

74

11

85

71

97

32

08

92

20

52

32

12

43

72

55

32

66

92

78

52

90

13

01

73

13

33

24

93

36

5

PEA

K LO

AD

-KW

WI NTER PERI OD

Grid - Classic Housing Grid - PH + 15 kWh battery

| 27

8 - OTHER LEADS

8.1 - Smart system for solar self-consumption

In order to increase the self-consumption ratio, two systems are suggested and described below.

8.1.1 - MyLight System’s Kit

Optimization of consumption and production is achieved with these two components:

- A Central Control Unit which manages and optimizes electricity flow in the house;

- Several SmartPlugs.

By combining their functions, domestic hot water and electrical appliances are used when electricity

production from solar energy is its maximum.

| 27

8.1.1 - Victron HUB 4 system

The Victron HUB 4 System is distributed by Victron Energy, based in Glasgow. This system is a grid-parallel energy storage system. It can be added in any existing photovoltaic system. The system is mainly constituted by these products:

- Batteries, any type of battery can be used; - A Victron colour control GX to monitor and control the system; - A Carlo Gavazzi energy meter for export/import measures, so the system is able to determine

when the battery must be charged or discharged; - The other components are the initial elements of the photovoltaic system.

passive detached single family house in aylesbury · energelio tél. :+33 (0)3.20.52.44.20 7 rue de...

Documents