Smart Grids implemented
on Scottish islands
Ruth Kemsley
Senergy Econnect Ltd
United Kingdom
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
Overview
1
Practical application of Smart Grid technologies
in island power systems
2
Wider applications of this Smart Grid knowledge
3
Extension to renewable electric transport
Off-grid islands in Scotland
Smart Grids
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
Fair Isle, Shetland
Distributed load management
1982
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
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
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
Isle of Rum
dam and pipeline
hydro generators
Isle of Rum - typical operation
30
Heating load
controller
25
Kinloch village
+ Castle
20
kW
Total hydro
output
Kinloch
Castle
15
10
Kinloch village
5
Kinloch village
0
15 Jan
12:00
16 Jan
00:00
16 Jan
12:00
17 Jan
00:00
17 Jan
12:00
18 Jan
00:00
18 Jan
12:00
19 Jan
00:00
19 Jan
12:00
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)
Island of Foula - 2009
Island of Foula - 2009
3.3kV
T2
T3
T4
T5
T6
T8
T7
School
T9
DISTRIBUTION TRANSFORMERS
400V
PHOTOVOLTAICS
3.3kV cable network
19.2kWp
G
~
no change to HV
modified LV protection
15kW
HYDRO
~
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
SUNNY BOY
INVERTERS
=
CHANGEOVER
UNIT
18kW nom.
~
~
30kW
30kW
DIESEL GENERATORS
MAIN POWERHOUSE
SUNNY ISLAND
INVERTERS
33kW nom
BATTERIES
140 kWh
(C100)
~
=
Isle of Eigg, Small Isles
Early 20th century
Pier hydro
~2002
upgraded Pier hydro
Kildonnan hydro
local LV networks
LAIG
2007-8
POWERHOUSE
KILDONNAN
WIND FARM
PIER
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
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
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
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
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
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
Summary
1
2
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:
3
would significantly improve economic and environmental
sustainability
would provide most benefits in marine transport cost savings
Thank you for listening
Any questions?
ruth.kemsley@senergyworld.com
References & further information
http://www.fairisle.org.uk/FIECo/index.htm
www.windandsun.co.uk/Projects/foula.htm
www.windandsun.co.uk/Projects/eigg.htm
http://www.smallwindindustry.org/fileadmin/ewea_documents/documents/proje
cts/swiis/track_records/050511MUCKisland.pdf
www.senergyworld.com/products/productsandservices/senergyalternatives/ec
onnect/econnectproducts/islandgrids
www.senergyworld.com/products/productsandservices/senergyalternatives/ec
onnect/econnectproducts/powaplug