The Orkney Islands are an archipelago in the Northern Isles of Scotland, situated off the north coast of Great Britain. Orkney comprises approximately 70 islands of which 20 are inhabited, totalling a population of approximate 21,349 people (2011 census).
Orkney’s main industries include farming, fishing and tourism, with power generation becoming an ever-larger employer. More than 90% of agricultural land is used for grazing for sheep and cattle, with cereal production utilising about 4%. The islands are renowned for their wind, wave and tidal energy resources.
In 2003, the electrical power required to meet local demand was sourced from mainland Scotland (via two 33 kV distribution subsea cables), gas turbines (e.g. on island of Flotta), the Kirkwall Power Station (16MWe diesel oil generator) and a small amount from renewable sources.
Reliance on electricity import via the subsea cable and fossil fuel generation technologies continues to decrease as the installed capacity of renewable energy technologies increase.
There are a variety of projects across the Orkney Islands which demonstrate innovative approaches to power generation, storage, distribution and demand side management; as well as local experience and expertise.
|Orkney world leading experience and expertise:
Due to the high cost of conventional grid reinforcement an innovative solution to Orkney’s grid capacity constraints was successfully developed, a form of smart grid known as Active Network Management.
In 2009, the fully operational Active Network Management (ANM) was switched on, making better use of the existing network by instructing generators to control their output, in real time, to match the available network capacity. It allows monitoring of the power flows at several points on the network. This is particular important given that approximately 30 large and 500 domestic wind turbines installed are connected to the grid (In 2014, the total power rating for installed wind turbines in Orkney was 48.4 MW. By comparison, the peak winter demand for the same period was 35.7 MW (SSE).
The ANM system allowed the connection of an additional 20 wind power generators with a combined maximum output of 24.2 MW. The Orkney Isles now have over 72 MW of distributed generation connected in addition to a further 5 MW of microgeneration.
All wind turbines in Orkney are connected to the grid and either have firm or non-firm generation connections, based upon their date of construction. New non-firm connections (NNFG) allow the distribution network operator, SSEN, to curtail a turbine, reducing its power output or stopping it completely. No compensation is available for under-production while an NNFG turbine is curtained – this presents an issue for renewable energy generators whose financial viability is effected by under-production.
ANM showcases the capabilities of the Scottish supply chain to provide energy solutions for an islanded network. The hardware that controls the ANM system was designed and manufactured by Smarter Grid Solution, a Glasgow based Scotland who have successfully exported their technology widely within the United States. The University of Strathclyde, again based in Glasgow, assisted with the design of the scheme, whilst it was implemented by another Scottish company, SSEN.
In 2013, SSEN installed a 2MW lithium ion battery at Kirkwall Power Station, and connected it to Orkney’s electricity distribution network. This pioneering trial, the first of its kind in the UK, aims to establish the viability of large scale batteries for electricity storage.
The 2MW lithium ion battery was provided by Mitsubishi, and has been integrated into the existing energy storage system within Orkney’s ANM network. The battery, which has already been trialled for two years in Japan, should make it easier to smooth out intermittent power generation from renewable sources by allowing the operator to store clean energy and release it when required. This ability to balance a variable energy output from renewable sources will become increasingly important as the world moves towards a decarbonised electricity generation mix.
Although the installation of the battery has not provided an immediate solution to constraints on the Orkney distribution network, it is hoped that the results of the study will help demonstrate that batteries could provide a cost effective way of freeing up capacity on the network and facilitating new connections in the long term.
District heating and heat storage
Heat Smart Orkney is based on three islands in the Orkney archipelago: Rousay, Egilsay and Wyre. The three islands have a population between them of about 260 people, where farming is the main economic activity.
Heat Smart Orkney (HSO) stemmed from several local needs: to reduce the curtailment impact of an ANM system (e.g. on a wind farm) and hence restore income for the community to forecast uncurtailed levels; and, to address fuel poverty by providing low cost supplementary heating using low cost electricity.
The principle behind the project is to convert excess electricity into heat to provide domestic heating and hot water. This is done via secondary domestic electrical heating systems which include: electric flow boilers, storage heaters and hot water immersion heaters. The primary heating system remains and is used when curtailment restriction do not apply.
In operation, the generating device (e.g. wind turbine) sends a signal to the HSO control system running on the Cloud. This happens just before the turbine is due to be switched off due to curtailment restrictions. This allows the control system to send a “switch on” signal to the secondary heating systems.
In theory, the use of the electrical secondary heating systems increases local electricity demand and should reduce the amount of wind turbine electricity output that is curtailed. This will operate independently of any existing contractual agreement or tariff already in place with the Distribution Network Operator (DNO) Scottish and Southern Energy (SSE).
The Building Innovative Green Hydrogen Systems in Isolated Territory (BIG HIT) is another project alleviating the impact of curtailment.
The project aims to demonstrate that Orkney Islands can become a replicable Hydrogen Territory, using curtailed renewable electricity generated locally can produce hydrogen to be used as clean energy for heat and transport.
In this project, hydrogen will be produced in Shapinsay by a hydrogen electrolyser using the curtailed energy generated from the Shapinsay Community Development Trusts (SDT) community wind turbine. Some of the hydrogen will be used to heat the Shapinsay primary school reducing the reliance on fossil fuels traditionally used for heat.
In addition to the local community projects, BIG HIT will demonstrate that hydrogen has a wider value to the local economy and will be transported to the mainland of Orkney on the inter-isles ferries through the use of a specially designed hydrogen tube trailers, which can be transported by local hauliers. The end uses for the hydrogen on the mainland of Orkney will include auxiliary power and heat for ferries in Kirkwall harbour, fuelling a fleet of electric/hydrogen hybrid vehicles through a purpose built hydrogen refuelling station (HRS) and potential to heat additional buildings in Kirkwall. The use of the hydrogen will be managed through the establishment of an Orkney hydrogen trading group.
Both projects highlight the innovation and forward thinking development of Scottish communities and their technical advisors, utilising local resources to implement solutions for the future that can be replicated on other grid constrained islands.
|Scottish partners (Heat Smart):
Scottish partners (BIG HIT):
Wave and tidal
European Marine Energy Centre (EMEC) operates 14 full-scale wave and tidal test berths – all fully occupied by marine technology developers. EMEC operates two smaller-scale wave and tidal sites for device, technique and component testing in less challenging sea conditions. EMEC’s team of specialists also provides a range of consultancy and support services, with their expertise much in demand from emerging and planned test sites around the world.
Numerous EU-funded marine projects are currently underway in Orkney, including the Scotrenewables-led Floating Tidal Energy Commercialisation (FloTEC) project, focused on the design and build of a mark 2 SR2000 tidal turbine a Scottish turbine designed and built in Scotland. Other successful Scottish tidal turbine developers include Nova Innovation, who have 3 turbines operating in Scottish waters and Nautricity.
Orkney has a fleet of over 100 electric vehicles from personal cars to commercial vans. Orkney Islands Council recently took delivery of the county’s first electric bus, which runs on the Kirkwall to Kirkwall airport route.
The Orkney Electric Vehicles project aimed to demonstrate the viability of electric vehicles (EV) in an island context for other island inhabitants, and to encourage further EV trials in Orkney, through each of the partner organisations leasing an EV from Arval for twenty-four months. It was hoped that the project would increase demand for free charging points, which would help the rate and ease of uptake of EV’s, and reduce ‘travel poverty’ in the islands. The island communities hope to reduce travel overheads for their respective Development Trusts, and this in turn brings the opportunity to link into demand side management studies, which (if scaled up) reduce constraint on community turbines. This would facilitate an increase in renewable energy generation by community owned wind turbines in the region, and resultant financial revenue created through their operation for investment in/use by the community.
The outcome has been positive, with a marked increase in the number of EVs on the three islands – it is noted that this is likely, in part at least, to be a result of the high level of publicity and direct contact between the Trust, the EVs and community members during the project period. For example, one of the leased vehicles was sent to the All Energy in Aberdeen conference two years running, while Project Officers also presented on the project at Community Energy Scotland’s Conference in Edinburgh in 2013. In addition, Trust overheads have been reduced through staff and Directors substituting the use of EVs for traditional non-renewable vehicles. It is also suggested that the project has encouraged the development of a smart EV charging project.