Oxford case study on storing and sharing solar-generated electricity:

Insights from Project ERIC

Energy Storage Summit, 28 April 2016 Twickenham

Drivers for the project from the local authority’s perspectives and

experience with the project

Debbie Haynes Oxford City Council

Getting started … (in Rose Hill)

• Fear of the new … But • Lots of inspiring and bright people • Strong community input • Area of high % of social housing • Strong joint commitment and drive • Previously had ‘piloted’ 5 solar PV and 2 Maslow installs So … OCC – commitment of 30 solar PV installs and batteries

Oxford City Council: Aims project met

• Reduce energy bill of tenants • Generate long term income • Reduce carbon footprint of the

city • Increase sense of community and

positive environmental interest • Support innovative research

project • Promote community energy

What was/is it?

• 49 Solar PV installs into our social housing (Joju Solar) • 49 battery installs (Maslows) • Some LED lighting (DC powered) • Data monitoring and interviews

What this actually involved

• Desktop PV analysis of 2kWp and SW to SE orientation/ no shading = PV shortlist

• Roof replacement/ tenant interest checks • Property surveys - numerous • Building surveyor managed project for OCC • Tenant liaison officer (part time) supported Bioregional • Regular project meetings coordinated • Considerable input in terms of resources • Sometimes varied from specification (1.25 to 3kWp)

Council resources

Building Surveyor • Project managed all work/surveys • Technical/legislative liaison • Electrical/structural issues and checks Tenant liaison officer • Coordinated surveys • Produced literature with visual aids. Promote benefits and

understanding • On hand to deal with problems/worries

What we learned (site)

• Site survey must quickly follow desktop survey • Access to homes difficult • Number of surveys high and intrusive • Tenants – may not want PV/batteries “our housing project, their home”

• Metering/ broadband problems • Electrical checks vital • Stick to specification • Generally good feedback – even ‘PV envy’

What we learned (broader)

• Additional requirements of Maslow battery • Local area – need to be fair (specification) • Trial means teething problems • Data protection agreements • Call outs/maintenance issues • Tenant liaison vital • Can’t predict everything…

Also …

• PV and Moixa batteries in Rose Hill Community Centre

project ericre-energising communities

Chris WrightCTOMoixa Technologychris@moixaenergy.com

www.moixatechnology.comwww.meetmaslow.com

Moixa Technology Maslowenergy storage system

GridShareTM

VPP cloud platform

Moixa hardware and aggregation platform

The Moixa Technology offering: • The Maslow proprietary hardware, all-in-one energy-storage solution • The GridShare™ SaaS platform that monitors and controls distributed energy

resources in the field, and aggregates them into groups to trade on to the energy market.

Proprietary Maslow hardware

Software GridShare™ aggregation platform

Analysis and control tools

Trading to energy markets

GridShare™ VPP cloud platform

National Grid

dashboards Maslow systems

3rd party systems integration

Bi-directional EV charge Chademo - Nissan

TCPip

analytics

HyperCat energy integration

Project Eric dispatch: Substation monitoring

Testing local grid effects:

28th April test dispatch of a small subset of 20 houses, 1hr dispatch event.

This is visible on the sub-station monitoring installed by SSE PD for the project.

Revenue & payback model The revenue model below illustrates a financed system over 10 years @ 6% for a household with an existing solar PV system.

Example revenue steam: trading

24 Oct 15 Average October day £120/MWh trading range

16 May 15 High wind day, market is long £70/MWh available Payment to take energy

Project evaluation to date

Prof Rajat Gupta & Dr Adorkor Bruce Oxford Brookes University

Evaluation methodology

• Monitoring: – Household electricity consumption – Solar PV electricity generation – Contribution of smart electricity storage

• Conducting dwelling and household surveys • Undertaking energy audits of electrical appliances Data for evaluation obtained from multiple sources

Project evaluation and findings to date

Evaluation elements: • Dwelling and household characteristics • Feedback from household interviews • Household baseline electricity consumption • PV generated electricity • Contribution of smart electricity storage –

household and community level

ERIC dwellings in Rose Hill

• 82 households in Rose Hill – 74 social rented – 8 owner-occupied

• All households have solar PV systems (1.5 – 4kWp)

• 2kWh Maslow battery installed in all households

• 60 out of 82 households interviewed (73% response rate)

Dwelling and household characteristics

• Gas central heating in all dwellings • Energy efficiency rating B to D • Variety of household sizes - 1 to 8 householders • Variety of household types – e.g. families with dependent children, single person over 65 • Variety of occupancy patterns – e.g.

always occupied, evenings and weekends only

• 55% of the households are always occupied

Bungalows

Flats

Older dwellings

New dwellings

Householders energy attitudes and feedback

Energy attitudes

• 75% of ERIC householders are concerned about rising energy prices

• 80% frequently think about their household energy use

• 72% are concerned about climate change

• 60% are concerned about energy supplies

Feedback

• Different stakeholders have different reasons for participation in Project ERIC – owner-occupied householders

are interested in promoting new technology

• Generally good experience with the installation of the Maslow unit

Household baseline electricity use

• Average daily household electricity use range from 2.9kWh to 21.7kWh Median = 6.9kWh, Mean = 7.3kWh

0

2

4

6

8

10

12

14

16

18

20

22

24

H64

H75

H17

H34

H74

H63

H07

H67

H12

H68

H65

H73

H35

H70

H59

H44

H20

H84

H62

H83

H71

H11

H23

H05

H79

H55

H21

H30

H81

H36

H37

H14

H18

H16

H49

H15

H60

H39

H33

H10

H38

H40

H31

H46

H42

H25

H53

H24

H57

H09

H19

H85

H80

H08

Aver

age

daily

hou

seho

ld e

lect

ricity

use

(kW

h)

ERIC Households

Characteristics of electricity use Weak correlation between household size and average daily electricity use (r2 = 0.33)

Weak correlation between number of appliances owned and average daily electricity use (r2 = 0.27)

0

5

10

15

20

25

30

35

40

45

50

0

5

10

15

20

25

H64

H75

H17

H34

H74

H63

H07

H67

H12

H68

H65

H73

H35

H70

H59

H44

H20

H84

H62

H83

H71

H11

H23

H05

H79

H55

H21

H81

H30

H36

H37

H14

H18

H16

H49

H15

H60

H39

H32

H10

H38

H40

H31

H46

H42

H25

H53

H24

H57

H09

H19

H85

H80

H08

Num

ber o

f app

lianc

es o

wne

d

Aver

age

daily

hou

seho

ld e

lect

ricity

use

(kW

h)

ERIC Households

Ave daily electricity use Number of appliances owned

0

1

2

3

4

5

6

7

8

9

10

0

5

10

15

20

25

H64

H75

H17

H34

H74

H63

H07

H67

H12

H68

H65

H73

H35

H70

H59

H44

H20

H84

H62

H83

H71

H11

H23

H05

H79

H55

H21

H81

H30

H36

H37

H14

H18

H16

H49

H15

H60

H39

H32

H10

H38

H40

H31

H46

H42

H25

H53

H24

H57

H09

H19

H85

H80

H08

Num

ber o

f hou

seho

lder

s

Aver

age

daily

hou

seho

ld e

lect

ricity

use

(kW

h)

ERIC Households

Ave daily household electricity use Number of householders

PV generated electricity

• Approximately 91MWh of electricity has been generated since April 2015

0

500

1000

1500

2000

2500

3000

3500

4000

H85

H01

H02

H04

H06

H07

H09

H10

H11

H12

H13

H14

H15

H16

H17

H18

H19

H20

H21

H22

H25

H26

H27

H28

H29

H30

H08

H24

H23

H80

H81

H66

H67

H70

H71

H72

H73

H74

H75

H76

H77

H65

H68

H59

H60

H61

H62

H63

H64

2kWp

2.5kWp 2.753.25 3.5 3.8 4 1.5kWp 2kWp 3kWp

2.5kWp

Generation in 1 year Generation in 7 months

PV g

ener

ated

ele

ctric

ity (k

Wh)

Generation in 1 year: Apr-15 - Mar-16 Generation in 7 months: Sep-15 - Mar-16

Contribution of smart electricity storage – household level

0

20

40

60

80

100

0

0.2

0.4

0.6

0.8

1

1.2

00 02 04 06 08 10 12 14 16 18 20 22

Elec

tric

cha

rge

in M

aslo

w (A

h)

Elec

tric

ity co

nsum

ptio

n an

d ge

nera

tion

(kW

h)

Hour of day

Household consumption (with Maslow) PV generation

Household consumption (without Maslow) Charge in Maslow

1) Electric charge in the Maslow starts to increase when PV electricity generation is greater than household consumption

2) Power from the Maslow is discharged when PV electricity generation is less than household consumption

3) Saving from use of stored electricity (reduced grid electricity demand)

Contribution of smart electricity storage – community level (n=40)

Aggregated electricity consumption and generation (March 2016)

Total consumption 9,831 kWh

Total PV generation 5,219 kWh

Total energy from Maslow 656 kWh

Total PV electricity consumed (assuming 50% used + storage)

3,266 kWh

% increase in PV electricity consumption 12.6%

% reduction in peak grid demand 11.2%

0

500

1000

1500

2000

2500

3000

3500

4000

0

5

10

15

20

25

30

35

40

00 02 04 06 08 10 12 14 16 18 20 22El

ectr

ic c

harg

e in

Mas

low

(Ah)

Elec

tric

ity co

nsum

ptio

n an

d ge

nera

tion

(kW

h)

Hour of day

Total electricity consumption (with Maslow) Total PV electricity generationTotal electricity consumption (without Maslow) Total charge in Maslow

Key findings

• There is a good range of households participating in Project ERIC – e.g. tenure, household size and occupancy patterns.

• Multiple sources of data have been useful to ensure reliability and accuracy of monitored data.

• There is currently limited householder understanding of the installed systems, particularly of the battery units, in the social-rented households.

• Relevant feedback on the performance of the technologies will help householders in optimising their behaviours in order to maximise the energy savings.

Oxford Brookes University | Low Carbon Buildings Group Prof Rajat Gupta | rgupta@brookes.ac.uk

Oxford City Council |Debbie Haynes (Energy Efficiency Projects Officer)

dhaynes@oxford.gov.uk | 01865 252566

Moixa Technology Ltd |Chris Wright (CTO) chris@moixaenergy.com

www.moixatechnology.com | www.meetmaslow.com

Thank you!