Community scale renewable energy systems

The Scottish and UK Government has promoted local renewable energy systems through financial incentives and the provision of support through organisations such as Community Energy Scotland. This has helped encourage uptake of such systems in Communities who have been able to organise themselves to take advantage. Local jobs have been created to support the local energy infrastructure.

Findhorn and the Isle of Eigg

The Island of Eigg is off the main electricity grid and previously relied on diesel generators for electricity which were expensive, noisy and produced undesirable air pollutants and carbon emissions. Connection to the main electricity grid was considered but a cheaper alternative was to establish a local renewable network of hydro, PV and wind technologies with backup battery storage. This system has run successfully for several years, 6 part time jobs were created to maintain the system.

Figure 3.5 Eigg Renewable Electricity System, hydro, wind, PV and battery storage.

Findhorn and Fintry rural communities on the mainland have grid connected renewable electricity networks which allow import and export of electricity with associated financial transactions which generate revenues and allow them to continue to invest and expand their networks. Fintry includes anaerobic digestion (AD) of farm waste feeding a generator which provides electricity and heat. Both communities have renewable heat networks based on biomass and electrical heat pumps, there is the potential to use also the waste heat from the Fintry AD.

These Scottish community energy systems point to potentials for replication in Brazil in rural communities either in portable energy systems for camps or permanent off or on grid systems in settlements.

During the research modelling was carried out (using HOMER and MERIT software) of the renewable systems of Eigg and Findhorn, the models were validated against monitoring data in each case. These models are now being used to evaluate potential future expansions of the energy systems to cover electrical, heating, hot water and transport needs (electric vehicles). The optimisation objectives considered were either energy independence from grids based on fossil fuels ('energy autarky') or cost optimality or a combination of both. Modelling was also carried out to investigate the potential land area that would be required to produce biomass for heating in the two locations.

Figure 3.6 Calibrated Model Outputs of Eigg Renewable Electricity System (HOMER software)

Figure 3.7 Illustration of Findhorn - Wind and PV, low carbon buildings - and Calibrated Model output

Figure 3.8 Findhorn hydro resource mapping.

Figure 3.9 Modelled Potential Power Output from Findhorn River Hydro System (MERIT software)

The modelling software has also been used to map the renewable energy potentials in Brazil and is now being used to assess options for camps and settlements. The software uses global databases as reference for the solar and wind energy resources at any given location, these resources are then used together with validated models of renewable systems and storage to determine the optimum system configurations for the location and energy requirements of the particular communities.

Figure 3.10 Renewable energy system assessment: example, Quirinópolis camp (HOMER software).

Fintry

Fintry is a pioneer of new models of community ownership and community energy. In 2007, it acquired its own one megawatt wind turbine as part of a commercial development of the Earlsburn wind farm and set up a community development trust, Fintry Development Trust, (FDT), whose aim is to create a carbon neutral Fintry (FDT, 2011).

In 2007, Fintry Development Trust (FDT) became the first community in the UK to enter a joint venture with a windfarm developer (Falck Renewables). FDT owns 1/15th (2.5MW) of Earlsburn Windfarm. FDT set up this project and continues to manage the resulting income on behalf of the community. The aim of the development trust is to reduce local carbon emissions and enhance the sustainability of the Fintry community through the implementation of a wide range of energy related projects.

Fintry is a rural community set in the Campsie Fells, about 20 miles from Stirling and Glasgow and has a population of approximately 700 people. As with most small rural communities, Fintry struggles to be a viable economic centre for employment. The village is relatively wealthy as it is a largely commuter community and has high social capital with thriving community organisations. However, numbers at the primary school continue to decline as the population ages. Many services have closed down or moved to other villages, such as the shop, petrol station, nursery, after-school club, healthcare and post office. The lack of services and local employment in Fintry is thought to discourage families moving to the village. Nevertheless, small enterprises serve the existing population, for example: Fintry Sports Club provides a small shop for essential provisions and newspapers; a post office service is provided by a mobile van; The Fintry Inn has a micro-brewery and Knochraich Farm is a local dairy producing yogurt and ice cream.

With carbon neutrality in mind, FDT has targeted building energy efficiency and fuel sources. Since its inception, FDT has employed energy advisors to facilitate energy developments. The heat loss of 246 out of 333 homes has been assessed and their insulation improved. 120 renewable energy systems have been installed, including biomass boilers for commercial buildings, such as The Fintry Inn and Fintry Sports Club and a district heating system has been installed at Balgair Castle Holiday Park which supplies heating and hot water to 26 park homes. FDT has supported those in fuel poverty with a Warm Homes Fund and promoted renewable technologies through Fintry’s own Renewable Energy Show (FRESh in 2012 and 2014).

Historically, Fintry’s economy was based around agriculture and a cotton mill. The mill has long gone and the agriculture does not feed the local community. FDT have created raised beds for vegetable growing, planted a community orchard and promoted honey production and local growing, and Knockraich Creamery produces artisan yogurt and ice cream, but the community is still a long way from being sustainable in its own food production. With the absence of abattoirs and grazing suitable for finishing animals before slaughter, no meat is produced and consumed locally (Winther, 2014;Winther et al., 2015) .

Water continues to be an issue with abundance being the problem rather than drought. Natural watercourses and rainwater run-off have been connected to Fintry’s drainage systems, resulting in flood events at the sewage treatment works. In the first six months of 2014 46,000m3 of untreated diluted effluent were released in 340 flood events into the SAC river, the Endrick Water, which ultimately leads to the pristine waters of Loch Lomond (SNH, 2014).

Overall, consumption in Fintry is still not sustainable, despite leading the way in retro-fitting renewable energy technologies and insulation in homes and Fintry being a net exporter of energy. Food is still sourced from the global food supply chain through urban supermarkets and the community is still reliant on fossil fuels and internal combustion engine vehicles for transport. Constant funding constraints have resulted in nascent projects failing (such as the community car share scheme, Fintry Energy Efficient Transport). Projects are reliant on significant volunteer effort, which is not sustainable in the long term, as volunteers fatigue as they balance community volunteering with paid work and family responsibilities. Also, challenges in matching local energy generation to consumption means that the community is still reliant on fossil fuels for energy. It is this issue with which FDT is currently focussing.

Fintry sees itself as a place of innovation: in 2015 Fintry undertook a community-wide consultation to develop a Masterplan for the community and they have many projects that they would like to take on to create a thriving community. The opportunity to purchase the wind turbine acted as a catalyst for Fintry embarking on sustainable development. This has been enabled by technology and a joint venture with a global corporation, but this model has not been replicated to any great extent across Scotland.