Project: ACCESS (Assisting Communities to Connect to Electric Sustainable Sources)
Technology: A virtual network linking a community-owned Hydro to local heat demand
Location: Mull and Iona
CARES funding: Local Energy Challenge Fund £1.8 million
Project timescale: March 2015 – May 2018


ACCESS (Assisting Communities to Connect to Electric Sustainable Sources) was a project launched by Community Energy Scotland in cooperation with project partners Element Energy, Mull and Iona Community Trust, SSE Retail, VCharge UK and project advisors SSEN.

ACCESS aimed to help local communities generate their own renewable energy by offering ‘flexible connections’ in areas were tapping into the existing grid is difficult. By using these connectors, it would be possible to manage the local energy network more effectively.

The ACCESS trial aimed to show that it would be possible to do this by virtually linking the output of an existing generator, the community-owned hydro on Mull, to local electrical demand in the form of smart storage heaters installed in local homes and businesses.

Project aims and objectives

Garmony Hydro is a 400kW run of river hydro scheme owned by Green Energy Mull on behalf of the Iona Community Trust at Garmony, on the eastern side of the Isle of Mull. It is estimated that Garmony Hydro should generate over 1GWh of power each year, or about 3.5% of the island’s consumption.

An increasing number of renewable energy installations cannot easily connect to the grid because of limitations on how much new generation can be accepted. As a result, many renewable energy projects are not able to progress.

ACCESS aimed to help more local communities generate their own renewable energy by offering ‘flexible connections’ in areas where tapping into the existing grid is difficult. These ‘flexible connections’ are especially important in areas where the electricity grid is already at full capacity (i.e. it cannot take any new electricity generation), or where the network wires need expensive upgrades or replacements.

By fitting remote-control devices to domestic heaters, hot water cylinders and other appliances, it is possible to effectively manage the local energy network. To avoid overloading the grid you simply turn the devices on/off to match the generation output of the local energy installation.

Controls were also installed at the hydro station, enabling generator output to be controlled remotely, providing a second, failsafe line of control should switching off the domestic heaters prove insufficient.

Importantly, comfort levels in people’s homes are still set by the inhabitants who remain in control of their heating requirements.

By using these ‘flexible connectors’, many more community projects will be able to circumvent existing limitations that would otherwise prevent the effective use of renewable energy installations. This in turn will reduce the amount of greenhouse gases associated with energy use and further support local economies.

Outcomes and achievements

Community Energy Scotland wanted to use Garmony Hydro to test the real-life application of ACCESS and recruited more than 75 households across Mull and Iona to take part.

They fitted the households with smart ‘Dynamo’ switches that could be used to manage the appliances remotely sometimes modifying or replacing their existing heating and/or hot water appliances in the process. They also fitted the Garmony Hydro generator with additional equipment to monitor the main electrical connection from the mainland to the island.

Both these measures allowed for a failsafe line of control that was used to mitigate grid constraints without jeopardising the comfort level of the participating households.
There were benefits to all parties in various ways. The generator benefits by increased output and householders benefit from increased use of local, low carbon energy generation, controlled levels of comfort and possible reduced energy consumption. The network benefits from reduced peaks and troughs in power flow leading to reduced thermal losses, and the Distribution Network Operator benefits from a better controlled part of the network. There are also clear environmental benefits as less power is wasted and more renewable energy generation is supported.

Lessons learned

The project clearly demonstrated that the ACCESS system is a robust, stable and responsive method of managing local energy demands in real-time. It also provides a practical and efficient commercial model for community groups that would otherwise be unable to take full advantage of their renewable energy installations.
As with all development projects, however, ACCESS faced several challenges and learning points were identified. These are summarised below.

Participant relations

ACCESS showed that clear, background information is required to build the confidence of participants but providing ‘just the right amount’ of information was challenging. It also highlighted that resolving issues quickly was important to protect the reputations of the local groups involved, and that with multiple customer-facing points a central coordinator for participant engagement was required.

Economic incentives

The current peak/ off peak structure is a barrier to the roll out of this approach but a local tariff proposition, similar to Radio Tele-Switch tariffs, could work. Additional revenues could also be realised by providing energy services to operators. This could widen the scope for community energy projects and provide an incentive to community energy groups to take part.

Installation and maintenance

The installation process must be simple to avoid the risks associated with installers fitting new devices. Reliable internet connections are particularly important but cannot be assumed, especially in rural areas. Locally based expertise will also be essential to install devices and deal with maintenance issues, although technical capability in the local area may take time to build up.

Control strategies for curtailment mitigation

The project demonstrated that residents use their heaters differently (in terms of frequency, controls and settings), for example) but that ultimately a project will need to work with the behaviour of those taking part rather than expecting people to immediately change their behaviour. More importantly, the project must ensure that there are no unforeseen or expensive consequences for participants who continue to use unorthodox control methods under a new system.

Project coordination

It is important to keep a continuity of trained staff in each partnership so that teams are kept up to date. Being aware of varying timescales, and not underestimating the time and resource needed to ‘join the dots’ across partners when addressing problems, is also required. Protecting the data of participants in a project with multiple stakeholders is also crucial.