1. Smart Grids implemented on Scottish islands
Ruth Kemsley
Senergy Econnect Ltd
United Kingdom

2. Senergy Econnect
Part of Senergy Alternative Energy
Offices around the world
Electrical engineering
All forms of renewables
50% of all wind commissioned in Great Britain
Smart Grid and Active Network technology group

3. Overview 1
Practical application of Smart Grid technologies in island power systems
Wider applications of this Smart Grid knowledge
Extension to renewable electric transport 2 3

4. Off-grid islands in Scotland

5. Smart Grids

6. Smart Grids
Features
distributed and diverse generation
high usage of renewables
variable energy tariffs
load management
energy storage
communications
All implemented (at small scale) on Scottish islands
All these islands have achieved 100% renewable operation

7. Fair Isle, Shetland Distributed load management 1982 1998 2009
60kW wind turbine with diesel back-up
bespoke control system
system frequency controlled by heating loads distributed around island
each house has 2 circuits - "heating" (cheaper) and "service" (more expensive)
1998
100kW wind turbine added
2009
operating successfully - frequent use of 100% wind
islanders considering adding energy storage to improve operability

8. Isle of Muck, Small Isles
Central control with radio communications
1999
2 x 25kW Vergnet wind turbines with diesel back-up
battery energy storage
PLC-based control and generator scheduling
radio-controlled load and tariff management
3.3kV network
2008
feasibility study to look at increasing battery capacity and improving operability

9. Isle of Rum, Small Isles Frequency-based load management
Early 20th century
DC hydro generator and accumulator energy storage
DC supply to Kinloch Castle
1970s
2nd hydro turbine added and AC distribution network
1984
system refurbishment
central heating loads in Castle absorb surplus hydro energy
bespoke heating load controller
1997
load-shedding Powaplugs added to prevent system overloads
2008
feasibility and design for addition of energy storage and increased hydro capacity

10. Isle of Rum
dam and pipeline
hydro generators

11. Isle of Rum - typical operation

12. Island of Foula, Shetland
Distributed generation and load management
1980s-90s
wind / hydro / diesel
bespoke control system using cable communications
frequency-based load management
variable tariffs
3.3kV distribution network
2007-8
refurbished hydro, distribution network, load management
Sunny Island inverter system
battery energy storage
PV / diesel
frequency-based generator management
(wind)

13. Island of Foula

14. DISTRIBUTION TRANSFORMERS
Island of Foula
3.3kV T2 T3 T4 T5 T6 T7
School T8 T9
DISTRIBUTION TRANSFORMERS
400V
PHOTOVOLTAICS
19.2kWp G
3.3kV cable network
no change to HV
modified LV protection
Revised renewables-based system
energy storage
planning issues with wind turbines
increase use of hydro resource
addition of PV for summer months
frequency-based power regulation
revised demand-side management
diesel generator back-up ~
15kW
HYDRO ~ =
SUNNY BOY
INVERTERS
18kW nom.
CHANGEOVER
UNIT
SUNNY ISLAND
INVERTERS ~ = ~ ~
33kW nom
30kW
30kW
DIESEL GENERATORS
BATTERIES
140 kWh (C100)
MAIN POWERHOUSE

15. Isle of Eigg, Small Isles
Early 20th century
Pier hydro
~2002
upgraded Pier hydro
Kildonnan hydro
local LV networks
LAIG
2007-8
Laig hydro
refurbished old hydros
11km 3.3kV cable network
Sunny Island system with battery energy storage
PV / diesel / wind
frequency-based generator and load management
POWERHOUSE
KILDONNAN
PIER
WIND FARM

16. Demand / generation profiles
Evaluating existing energy and power demand
Estimating future demand
growth in number of consumers
increased supply period (24-hour power)
increased range of consumer goods
possible use of renewable electrical heating (demand-side management)
new technologies (e.g. electric vehicle charging)
Estimating generation output
annual / monthly / daily
allowing for variations

17. Issues and technologies
Connecting renewables into electrical system
Foula, Eigg, Rum, Fair Isle - AC connected - more flexible
Muck - DC connected - generation close to batteries
Managing the power balance
variable renewable input
insufficient or surplus renewable power
energy storage - hydro storage, batteries, diesel fuel (!)
integrating battery inverter control with generator control
load management
Controlling voltage
generator / inverter control
careful system design

18. Issues and technologies
System management, operation and support
significant community involvement (more than on mainland)
robustness, reliability, and affordability are key to success
remote support from equipment suppliers is essential
Metering
manual meter reading
switching between multiple meters (frequency or radio) to change tariff
Smart Meters more expensive, but costs now falling
Load management
systems without energy storage need to make maximum use of available renewables
even systems with energy storage sometimes have surplus renewable power
can help to utilise surplus power
can also reduce peak power demand and avoid energisation problems

19. Applying these Smart Grid techniques
Distributed renewable generation
output needs to be controllable / constrainable to integrate with grid at high % renewable penetration
use simple and autonomous generator control as much as possible
Load management
helps with integration of variable renewable sources
control signalling required - cannot use system frequency on interconnected grids - communications systems needed
need to incentivise to encourage consumers to engage

20. Extending use of renewable electricity
Electric vehicles
not a "bonus" load - need to be charged
need to size renewable power system for charging
can vehicle charging be included in demand-side management?
typical vehicle storage values comparable with island battery capacities
Electric boats?
distances on islands are often small
distances to islands are large and ferry / transport fuel costs are high

21. 1 2 3 Summary Small island power systems in Scotland have already:
implemented a wide variety of Smart Grid technologies
achieved high usage of renewable energy
learned useful lessons from their experience
The Smart Grid knowledge gained:
can be applied to mainland grid situations
will help to improve sustainable energy use
may need to be adapted in some cases
Renewable electric transport:
would significantly improve economic and environmental sustainability
would provide most benefits in marine transport cost savings 2 3

22. Thank you for listening
Any questions?

23. References & further information
cts/swiis/track_records/050511MUCKisland.pdf
onnect/econnectproducts/islandgrids
onnect/econnectproducts/powaplug