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

Practical application of Smart Grid technologies in island power systems

Wider applications of this Smart Grid knowledge

Extension to renewable electric transport

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Off-grid islands in Scotland

Smart Grids

Smart Grids

Featuresdistributed 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

198260kW 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)

1998100kW wind turbine added

2009operating successfully - frequent use of 100% wind

islanders considering adding energy storage to improve operability

Isle of Muck, Small Isles

Central control with radio communications

19992 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

2008feasibility study to look at increasing battery capacity and improving operability

Isle of Rum, Small Isles

Frequency-based load managementEarly 20th century

DC hydro generator and accumulator energy storageDC supply to Kinloch Castle

1970s2nd hydro turbine added and AC distribution network

1984system refurbishmentcentral heating loads in Castle absorb surplus hydro energybespoke heating load controller

1997load-shedding Powaplugs added to prevent system overloads

2008feasibility and design for addition of energy storage and increased hydro capacity

Isle of Rum

dam and pipeline

hydro generators

Isle of Rum - typical operation

Total hydro output

Kinloch village + Castle

Kinloch village

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15 Jan12:00

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kW

Kinloch village

Kinloch Castle

Heating loadcontroller

Island of Foula, Shetland

Distributed generation and load management

1980s-90swind / hydro / diesel

bespoke control system using cable communications

frequency-based load management

variable tariffs

3.3kV distribution network

2007-8refurbished 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

T2 T3 T4 T5 T6 T7School

T8 T9

~HYDRO

3.3kV

400V

15kW

PHOTOVOLTAICS

19.2kWp

~=

G

~

MAIN POWERHOUSE

DIESEL GENERATORS

30kW

~ =SUNNY ISLAND

INVERTERS

BATTERIES

33kW nom~

30kW

CHANGEOVERUNIT

140 kWh (C100)

SUNNY BOYINVERTERS

18kW nom.

3.3kV cable networkno change to HVmodified LV protection

Revised renewables-based systemenergy storageplanning issues with wind turbinesincrease use of hydro resourceaddition of PV for summer monthsfrequency-based power regulationrevised demand-side managementdiesel generator back-up

DISTRIBUTION TRANSFORMERS

Isle of Eigg, Small Isles

KILDONNAN

WIND FARM

LAIG

POWERHOUSE

PIER

Early 20th centuryPier hydro

~2002upgraded Pier hydroKildonnan hydrolocal LV networks

2007-8Laig hydrorefurbished old hydros11km 3.3kV cable networkSunny Island system with battery energy storagePV / diesel / windfrequency-based generator and load management

Demand / generation profiles

Evaluating existing energy and power demand

Estimating future demandgrowth in number of consumersincreased supply period (24-hour power)increased range of consumer goodspossible use of renewable electrical heating (demand-side management)new technologies (e.g. electric vehicle charging)

Estimating generation outputannual / monthly / dailyallowing for variations

Issues and technologies

Connecting renewables into electrical systemFoula, Eigg, Rum, Fair Isle - AC connected - more flexibleMuck - DC connected - generation close to batteries

Managing the power balancevariable renewable inputinsufficient or surplus renewable powerenergy storage - hydro storage, batteries, diesel fuel (!)integrating battery inverter control with generator controlload management

Controlling voltagegenerator / inverter controlcareful system design

Issues and technologies

System management, operation and supportsignificant community involvement (more than on mainland)robustness, reliability, and affordability are key to success remote support from equipment suppliers is essential

Meteringmanual meter readingswitching between multiple meters (frequency or radio) to change tariffSmart Meters more expensive, but costs now falling

Load managementsystems without energy storage need to make maximum use of available renewableseven systems with energy storage sometimes have surplus renewable powercan help to utilise surplus powercan also reduce peak power demand and avoid energisation problems

Applying these Smart Grid techniques

Distributed renewable generationoutput needs to be controllable / constrainable to integrate with grid at high % renewable penetration

use simple and autonomous generator control as much as possible

Load managementhelps 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 vehiclesnot 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

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

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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/projects/swiis/track_records/050511MUCKisland.pdf

www.senergyworld.com/products/productsandservices/senergyalternatives/econnect/econnectproducts/islandgrids

www.senergyworld.com/products/productsandservices/senergyalternatives/econnect/econnectproducts/powaplug