1. Selling Storage What you need to know …. Dr Christian N Jardine
Technical Director, Joju Solar and Senior Researcher, Environmental Change Institute, University of Oxford

2. Residential Niches Commercial Rates of return Self-utilisation
Discharge
Motivations
Niches
Retrofit, solar+storage
Social housing
New builds
Commercial
High load factors
Other operational modes

3. Lets be honest about battery market
Huge interest in storage at present
The Tesla Effect
2015 – 500 domestic batteries nationwide (mainly trials)
2016 – batteries, new additions are sales
But ≈1500 installers offering batteries
Massively oversupplied
This won’t replace our old solar market
But an interesting additional product line

4. Classic load-shifting (autumn/spring)

5. Load-shifting (winter)

6. Load-shifting (summer)

7. So, broadly 3 modes of operation
Spring/Autumn
Broadly well balanced
Excess generation feeds battery
Discharges overnight
Winter
Not enough excess generation to fill battery
A kettle can empty it
Won’t last into the evening peak
Summer
Too much generation!
Battery can be full by mid morning
You end up exporting anyway
Damaging to grid = some smartness needed to control portfolios of batteries
All means you can’t have 100% self consumption
Clients need better understanding than just the classic model.

8. Domestic Solar PV rates of return
Price 3kW (£)
% self consumption
100% self consumption not possible in UK, beware missselling
Addition of battery broadly doesn’t change rate of return
But both lower than classic ’50% self consumption’ selling

9. What about discharge?
Batteries are brilliant technologies for storing electricity
They can soak up excess whenever it is available
But less thought given to discharge
This is when batteries are really valuable
Two broad models at present
Self-consumption
Peak shaving
In future
Flexible charge/discharge based on grid-wide fossil generation needed
Or other ancillary services

10. Self-consumption

11. Peak demand discharge

12. Market segmentation

13. It’s all a bit Brexit-y It’s all a bit Remain-y Motivations
Self-consumption
Peak shaving
Use your own generation
Discharge when most useful to system
Lower utilisation (battery might not empty)
High utilisation (battery empties)
“use it, or lose it”
“help get more renewables”
Insular, isolationist
Part of a larger system
Take back control
Be the control!
Self-reliance
Resilience in networks
It’s all a bit Brexit-y
It’s all a bit Remain-y
Know where you stand
This doesn’t work perfectly (yet) (ever?)
Would disconnect?
Wouldn’t disconnect
Ultimately VERY expensive
Networks reduce costs

14. Retrofit or Solar+storage
Better economics on solar+storage
Needs new customers, but:
Clear overall proposition
1 project = 1 lot of project management
So, lower overheads
5% VAT
Retrofit
Good access to customer base, but:
You might have sold solar on basis of 50% consumption
Poorer economics
20% VAT

15. Social Housing Council Purchases PV system Council Receives FiT
Pays back system
Tenant benefits from free electricity used (25%)

16. Tenant benefits from free electricity used (70%)
Social Housing
Council Purchases
PV system + battery
Council Receives FiT
Won’t pay back system
Tenant benefits from free electricity used (70%)

17. New Build market Increased interest in batteries for new build
But, new build market very CAPEX sensitive
Driven by Carbon legislation
Often see very small, poorly oriented/designed systems
Batteries add CAPEX
Batteries do not improve carbon under SAP
So no real driver here
Other than interest/experimentation

18. Commercial Storage Higher load factor in commercial buildings
Usage better aligned with solar
Implies opportunities for storing and shifting excess are lower
Low battery utilisation = poor economics

19. Commercial Storage Need to be cleverer Opportunities
Renewable generation time-shifting
Night/day time shifting
DUoS avoidance, TRIAD avoidance
Provision of ancillary services
Firm frequency response
Enhanced frequency response
Short-term operating reserve (STOR)
Fast reserve
But these need scale to access markets, even via aggregator
Probably need more than 1 to give adequate payback
Can you offer more than 1 service at once?

20. Conclusions 100% self-consumption not possible in UK
Be clear about what batteries can and can’t do
Especially seasonally
Better case for new solar+battery systems
Beware mis-selling when going back to old customers
Different motivations for batteries
Social housing & new build look difficult
Commercial demands has higher load factor
Commercial storage needs other income streams

21. Thank you for your attention!
@DrChrisJardine
jojusolar.co.uk