14 Nov 2018

Two of the UK’s most remote island communities get sustainable 24 hour electricity

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Wind and Sun Isles Installation Map Canna Sanday Fair Isle Title

The days of overnight power blackouts on Fair Isle, 25 miles south of Shetland, and on the islands of Canna and Sanday, off the west coast of Scotland, are being consigned to history thanks to new power systems supplied and installed this summer by  Wind & Sun.

Residents have ditched their diesel power generators in favour of new community-owned renewable electricity systems based on solar PV, wind, and battery storage technologies in a bid to cut fuel usage and costs.

Fair Isle

Located roughly halfway between Shetland and Orkney, Fair Isle is the UK’s most remote inhabited island and can be frequently cut off from the mainland for long periods due to weather and sea conditions. The 5km long island, famous for its’ knitwear and place in the shipping forecasts, is owned by the National Trust for Scotland and is home to a world renowned bird observatory (Fair Isle has been a focus of continuous scientific research into seabirds and bird migration since 1948).

Previously, power was supplied by a combination of wind and diesel, but homes were left without electricity between 11.30 pm and 7.30 am. Now all 55 inhabitants will discover the simple pleasures of instant power at any time.

Fair Isle Banner 02

Isles of Canna and Sanday

Canna is the westernmost of the Small Isles archipelago, in the Scottish Inner Hebrides approximately 25 miles from the mainland. It is linked to the neighbouring island of Sanday by a road bridge and sandbanks at low tide. The island is 4.3 miles (6.9 km) long and 1 mile (1.6 km) wide.

Also owned and managed by the National Trust for Scotland it was previously powered by diesel generators, but these were expensive to run and difficult to maintain.

Isles of Canna and Sanday Banner 02

Wind & Sun had been involved in helping develop the systems over the last five years after residents from Canna and Fair Isle visited our previous pioneering work on Isles of Eigg and Muck.

After shipping equipment from the mainland, Wind & Sun carried out the installation during several trips over the summer fitting the battery storage, inverter system and PV arrays (helped by our good friends from Solarkinetics and Pro-Fit Energy in Hereford). Finally the wind turbines were delivered, erected and connected up by Harbon Wind on Fair Isle and SD Wind Energy on the Isle of Canna/Sanday. SSE Contracting oversaw the projects as main contractors and carried out work including, installing control panel and new diesel generators; upgrading the island electrical networks; and connecting up new heating loads.

Wind & Sun then commissioned the system and in October they were both switched on!

The solar PV’s and wind turbines generate power for the island and charge the batteries. As batteries become full the frequency of the grid rises and this is used to automatically switch on heating loads located in community buildings to take advantage of windy weather using a number of frequency controlled switches.

In the event of insufficient renewable energy the back-up generator powers the island properties and re-charges the batteries. It is expected that this will be now needed less than 10% of the time.

The systems will be operated by local residents, both communities have established enterprises to own and operate the new equipment. Electricity will be provided to residents after which profits from the power generated will be used to cover operation and maintenance costs, and reduce bills for local homes and businesses

Wind & Sun have trained a local team to look after the scheme and will be providing on-going support to the islanders, monitoring performance and adjusting critical operating parameters remotely if required.

Steve Wade, Wind & Sun’s Managing Director said: "We’re pleased and proud to have built on our previous experience and completed our most challenging projects yet, both technically and in terms of logistics helping these island communities with some of the most sustainable electricity systems in the country."

Robert Mitchell, director of the Fair Isle Electricity Company, said: "It's a big day for the island, we've got our electricity project up and running and we're now going to be in the 21st century."

Canna Renewable Energy and Electrification Ltd (CREEL) director Geraldine MacKinnon said the community energy project had been a long standing ambition for islanders.
"The island is exposed to the full force of Atlantic gales and we can finally start to put that to good use. As well as reducing the noise and pollution from the generators the new scheme will give us the capacity to build additional houses here, so that we can increase the number of people who can make their home on this beautiful island. We're very grateful to all of our funders for their support in this vital project."

More information about the systems can be seen here.

Technical Description
Fair Isle system comprises:
  • Seven 3-phase battery/inverter clusters with 3 x Sunny Island Inverters, (21 inverters - 126kW total)
  • SMA MultiCluster Box -36 to marshal inverter cabling and to connect island loads and back-up generator
  • Seven banks of Rolls batteries  (588kWh useable capacity total)
  • 51.8kWp PV System - 192 x REC Solar multi-crystalline PV modules ground mounted using 12 Schletter PVMax North frames, connected to 3 x  Sunny Tripower 15kW inverters
  • 3 x 60kW Harbon wind turbines
  • 2 x 80kW back-up diesel generators
  • Remote monitoring using an SMA Data Manager to allow performance to be viewed over the internet and parameters adjusted remotely if needed.
  • Data is also available using Modbusfor a Scada monitoring system.

The system provides power for:           

  • Houses for 55 inhabitants
  • Post Office and shop
  • B&B visitor accommodation 
  • Primary School
  • Community Hall
  • Two churches
  • Fire Station
  • Airstrip
  • Scottish Water facility
  • Harbour
  • Lighthouse
  • Fair Isle Bird Observatory
Isle of Canna/Sanday system comprises:
  • Three 3-phase battery/inverter clusters each with 3 x Sunny Island Inverters, (9 inverters - 54kW total)
  • SMA MultiCluster Box -12 to marshal inverter cabling and to connect island loads and back-up generator
  • Three banks of 48 x Rolls batteries (225kWh useable capacity total)
  • 34.56kWp PV System made up of 128 x REC-270PE multi-crystalline PV modules ground mounted using 8 Schletter PVMax North frames and connected to 2 x SMA Sunny Tripower 20kW 3ph inverters
  • 6 x 6kW SD wind turbines with SMA Wind inverters
  • 2 x 60kW back-up diesel generators (one used at a time)
  • Remote monitoring is enabled using an SMA Data Manager allowing us to view performance over the internet and adjust operating parameters remotely if needed. 

The system provides power for:           

  • Houses for 15 inhabitants
  • Cafe and shop
  • B&B visitor accommodation
  • Farm buildings and workshops
  • Primary School
  • Two churches
  • Harbour buildings

Fair Isle is not connected to the National Grid but has been a renewable energy innovator in the past. In 1982 it was the site of what it is thought to have been the first commercial use of wind energy in Europe, based on a single turbine.

Since then, power generation on the three mile long island has evolved to combine diesel generators and two turbines. The diesel generators were automatically switched off if wind turbines provided sufficient power. Excess capacity was distributed through a separate network for home heating, with remote frequency-sensitive programmable relays controlling water heaters and storage heaters in the buildings of the community. The old system did not include energy storage so on still nights the lights sometimes went out.

Recently, the turbines had become difficult to maintain and were de-commissioned. The diesel generators continued to run but homes were left without electricity between 11.30 pm and 7.30 am.

With a total cost of over £3 million, funding for the new project has come from a range of sources – including a £1 million contribution from the Scottish Government using money from the EU.

Other funders include the Big Lottery Fund, Shetland Islands Council, Fair Isle Electricity Company, National Trust for Scotland and Highlands & Islands Enterprise.

Canna is not connected to the National Grid and power was supplied by diesel generators, but these were expensive to run and difficult to maintain.

A study was carried out in 2009 by IT Power into renewable energy options and in 2014 Wind & Sun were commissioned to produce an update to this based on the successful system we had recently installed on the Isle of Muck. After planning permission and funding was secured work started in early 2018.

The venture secured over £983,000 from the Big Lottery Fund and £150,000 from the Scottish Government, on top of an additional £100,000 from the SSE Highland Sustainable Development Fund. £50,000 each was also provided by Highlands and Islands Enterprise and the National Trust for Scotland.